Reefs at Risk - University of Floridaufdcimages.uflib.ufl.edu/UF/00/09/58/88/00001/reefs.pdfREEFS AT RISK A Map-Based Indicator of Threats to the World’s Coral Reefs D IRK B RYANT•

REEFSAT RISK

A M a p - B a s e d I n d i c a t o r

o f T h r e a t s t o t h e

W o r l d ’ s C o r a l R e e f s

D I R K B R Y A N T • L A U R E T T A B U R K E

J O H N M C M A N U S • M A R K S P A L D I N G

More than forty years ago, I slipped into a sunlitocean, clear as air, not far from Miami, Florida, andglided into a kaleidoscope forest of lavender sea fans,cavernous sponges, and giant stands of elkhorn coral.Thousands of fish moved about like animated frag-ments of stained glass, and other creatures—red starfish,black urchins, pink cucumbers, translucent anemones,blue shrimp, brown crabs, silver hydroids, and numer-ous others I could not name—embroidered every inchof aquatic real estate as far as I could see in all direc-tions. I witnessed that afternoon—my first of thousandsof dives on coral reefs around the world—a fair crosssection of the major divisions of life that have everexisted on this planet. Nearly all of the major phyla ofanimals and plants, as well as microbes, have at leastsome representation in the sea, and most include coralreef species. Only about half occur on the land, even inthe richest forests, swamps, and grasslands, Diving intoa healthy, productive coral reef system as I did on thatafternoon long ago, I traveled far into the history of lifeon earth, a surreal journey into time.

Recently, I returned hoping to relocate that under-water Garden of Eden, but found only barren coralskeletons shrouded with gray-brown sediment. Again, it seemed that I had traveled in time, only now the direc-tion was a swift fast-forward fantasy, a glimpse of thefuture. In my lifetime, I had witnessed change on a geo-logical scale, wrought by my species. The rapid growth ofpopulation in central and south Florida has had hiddencosts—the consumption, in decades, of species and nat-ural ecosystems millions of years in the making.

Worldwide, including in some parts of Florida, thereare coral reefs and entire reef systems that appear to beas pristine today as they were in ages past, but there isno doubt that there is an alarming global trend ofdecline. Until half a century ago, the worst threats tocoral reefs were storms, volcanic eruptions, periodic iceages, and occasional comets striking the Earth. However,since the 1950s, and at an accelerating pace, humankindhas added significant new pressures ranging from out-right mining of coral for building materials, widespreadpollution, and destructive fishing practices to loss ofvital related mangrove and seagrass ecosystems.

Concern has been growing for decades about the fateof coral reefs, especially in recent years as more andmore people have access to these underwater worldsand have come to realize their value for reasons thatboth embrace and transcend aesthetic, scientific, eco-nomic, and environmental considerations. Many morewho have not seen these notorious “rainforests of thesea” for themselves have been made aware of theirimportance and are motivated to want to do somethingto stay their swift loss. In 1997, which the UnitedNations declared as the “International Year of the Reef,”many questions were raised about just how widespreadthe problems are and what can be done to help protectwhat remains of healthy systems—and restore thosethat are damaged.

Although coral reefs have become the subject of thou-sands of research projects in the past few years, remark-ably little has been done to attempt a global assessmentof where and what are the most pressing problems. Yet,such information is vital if effective action plans are tobe devised. The authors of this report have taken aningenious approach to gauge the areas most at risk, aswell as to highlight those with varying degrees of sanc-tity, by correlating what is known about the distributionof reefs with the distribution of known human impacts.The result is a monumental overview, one that can beused to help guide conservation efforts on a grandscale—as well as up close, locally.

As human population grows, so will the pressures onthe natural systems that sustain us. Reefs at Risk: A Map-Based Indicator of Threats to the World’s Coral Reefs makesit possible to pull back and gain perspective on pastproblems as an effective way to anticipate—and perhapsprevent—potential disasters in the making. The fate ofcoral reefs, the ocean, and humankind forty years fromnow and forevermore will depend on the intelligence,motivation, and caring of people now alive. In that spirit, this report provides hope that we may succeed.

Sylvia A. EarleExplorer-in-Residence, National Geographic Society

Chairman, Deep Ocean Explorationand Research Organization

“In some areas human activity has destroyed entire reefs, converting them to algal-covered rubble. Who knows what

species, known and unknown alike, have already been wiped out? Who can say which ones will be winking out in

the near future, their intricate genetic codes, formed over millennia, suddenly gone. . . .”

—Osha Gray Davidson, The Enchanted Braid

ii R E E F S A T R I S K

A M a p - B a s e d I n d i c a t o r

o f T h r e a t s t o t h e

W o r l d ’ s C o r a l R e e f s

D I R K B R Y A N T • L A U R E T T A B U R K E

J O H N M C M A N U S • M A R K S P A L D I N G

Contributing Authors: Maria Carmen Ablan, Charles Victor Barber, Cindy Cabote, Herman Cesar, Terry Done,Maharlina Luz Gorospe, Hector Guzman, Pamela Hallock, Julie Hawkins, Art Hayman, Gregor Hodgson,

Stephen Jameson, Jim Maragos, Don McAllister, Lambert Meñez, Chou Loke Ming, Sara Moola, N.A. Muthiga,Kathleen P. K. Reyes, Callum Roberts, Frederick Schueler, Irene Uy, Sheila Vergara, Alan White, Clive Wilkinson

A joint publication by World Resources Institute (WRI), International Center for Living Aquatic Resources Management(ICLARM), World Conservation Monitoring Centre (WCMC), United Nations Environment Programme (UNEP)

REEFSAT RISK

Carol RosenPublications Director

Hyacinth BillingsProduction Manager

Cover Photograph byJan C. PostWorld Bank

Each World Resources Institute Report represents a timely, scholarly treatment of a subject of public concern. WRI takesresponsibility for choosing the study topics and guaranteeing its authors and researchers freedom of inquiry. It also solicitsand responds to the guidance of advisory panels and expert reviewers. Unless otherwise stated, however, all the interpreta-

tion and findings set forth in WRI publications are those of the authors.

Copyright © 1998 World Resources Institute. All rights reserved.ISBN 1-55963-257-4

Library of Congress Catalog Card No. 98-86375Printed in the United States of America on Recycled Paper

R E E F S A T R I S K 3

ContentsAcknowledgments ................................................................................................4Foreword ..............................................................................................................5Key Findings ........................................................................................................6Introduction ..........................................................................................................7Reefs and People: What Is at Stake? ....................................................................8Threats to Reefs ..................................................................................................11The Reefs at Risk Indicator ................................................................................17Status of the World’s Coral Reefs ......................................................................20Twelve Reefs at Risk ............................................................................................32Improving Our Knowledge Base ........................................................................38Protecting the Health of Coral Reef Ecosystems ..............................................41Technical Notes ..................................................................................................47About the Authors ......................................................................................................53Endnotes ..............................................................................................................54

MAPSINSIDE THE FRONT COVER:

Coral Reefs of the World Classified by Potential Threat from Human Activities ..................................................................................................................ii

MAP 1: Coral Bleaching Has Been Observed Worldwide................................................................13MAP 2: Destructive Fishing is Widespread in Southeast Asia ........................................................16MAP 3: Most Areas with High Reef Fish Species Diversity Are Threatened… ..............................30MAP 4: … And Most Areas With High Reef Fish Species Diversity Are Not Protected ................31MAP 5: Threatened Reefs and Signs of Promise—Reef Locations ..................................................33MAP 6: Marine Protected Areas of the World..................................................................................45MAP 7: Regions Used for Summary Statistics ..................................................................................50

REGIONAL MAPS:

Tropical Americas ............................................................................................................................22Indian Ocean ....................................................................................................................................23Seas of the Middle East ....................................................................................................................25East Asia ............................................................................................................................................26Pacific Ocean ............................................................................................................................28–29

The World Resources Institute would like to acknowledgethe United Nations Environment Programme, The BayFoundation, The David & Lucile Packard Foundation,The Henry Foundation, The Swedish InternationalDevelopment Cooperation Agency, and the United StatesEnvironmental Protection Agency for their encouragementand financial support.

The Reefs at Risk analysis would not have been possiblewithout the data and expert advice provided by our collab-orators—the World Conservation Monitoring Centre andthe International Center for Living Aquatic ResourcesManagement. We also wish to acknowledge the manyexperts who reviewed the Reefs at Risk methodology andresults:

Attended the methodology review workshop, August,1997 in Washington, DC: Tundy Agardy (ConservationInternational), Nicole Glineaur (World Bank), MareaHatziolos (World Bank), Jan Post (World Bank), JackSobel (Center for Marine Conservation), Edward Towle(Island Resources Foundation), John Tschirkey (TheNature Conservancy), John Waugh (IUCN-US).

Attended the workshop on methodology and results forthe world, September, 1997 in Manila: Chou LokeMing (Dept of Zoology-National University of Singapore),Terry Done (Australian Institute of Marine Science), CliveWilkinson (Global Coral Reef Monitoring Network,Australian Institute of Marine Science), Gregor Hodgson(Institute for Environment and Sustainable DevelopmentResearch Centre, Hong Kong University of Science andTechnology), Jim Canon (Conservation International),Perry Alino (Marine Science Institute, University of thePhilippines), Alan White (Coastal Resource ManagementProject), Pamela Hallock (Dept of Marine Science,University of South Florida), James Maragos (East-WestCenter), Malikusworo Hutomo (Research andDevelopment Center for Oceanography, IndonesianInstitute of the Sciences), Hector Guzman (SmithsonianTropical Research Institute, Panama).

Others who provided input (on methodology and/orresults): Bruce Potter (Island Resources Foundation),Don McAllister (Ocean Voice International), JaneLubchenco (Dept of Zoology, Oregon State University),

Bob Stallard (U.S. Geological Survey), John Milliman(VIMS, University of Virginia), Stephen Jameson (CoralSeas), Herman Cesar (World Bank), Lynne Z. Hale(University of Rhode Island).

Individuals who contributed to the species richness vsrisk analysis: Callum Roberts (University of York), DonMcAllister (Ocean Voice International), Julie Hawkins(University of York), Fred Schueler (Ocean VoiceInternational).

Staff from partner organizations involved inSeptember workshop and/or otherwise helped with themethodology: Mark Spalding (WCMC), John McManus(ICLARM), Sheila Vergara (ICLARM), Maria CarmenAblan (ICLARM), Irene Uy (ICLARM), Lambert Meñez(ICLARM), Maharlina Luz Gorospe (ICLARM),Kathleen P. K. Reyes (ICLARM).

Other external reviewers of draft: Sylvia Earle(National Geographic), Stephen Colwell (Coral ReefAlliance), Paul Holthus (World Wildlife Fund), RodneySalm (World Conservation Union—IUCN), Sue Wells(World Wildlife Fund), George Woodwell (Woods HoleResearch Center).

WRI staff involved in the workshops, reviewed thedraft and/or otherwise helped with the methodology(excludes authors): Walt Reid, Siobhan Murray, SheilaFerguson, Charles Barber, Allen Hammond, DanTunstall, Daniel Nielsen, Eric Rodenburg, Sara Moola,Jake Brunner, Norbert Henninger, Carmen Revenga.

WRI staff who assisted with fundraising, production ofthe report, and communication of results: Kevin Parker,Julie Harlan, Hyacinth Billings, Valerie Schwartz, CarolRosen, Frank Dexter Brown, and Mary Houser.

Special thanks to: Kate Sebastian (University ofMaryland) for assistance with map design, Rick Bunchand Walt Reid for consultations on color blindness, VicKlemas (University of Delaware) for providing data onriver sediment plumes used to calibrate the watershedmodel, and Siobhan Murray for assistance implementingthe watershed model.

4 R E E F S A T R I S K

Acknowledgments

Coral reefs, which are among the most biologicallydiverse ecosystems on the planet, are also some ofthe most ancient. They first appeared in the Mesozoicera some 225 million years ago and some living coralreefs may be as much as 2.5 million years old.Outstanding examples of our biological and naturalheritage, coral reefs are an important asset to localcommunities—serving as a source of seafood, provid-ing materials for new medicines, generating incomefrom tourism, and buffering coastal cities and settle-ments from storm damage. Yet, in just a few decades,human activities have devastated many of these bio-logically rich, ancient ecosystems. In the next two orthree decades, more are destined for destruction.

Until recently, almost nothing was known about theextent and condition of coral reefs. Unlike the changein rainforests, that in coral reefs is difficult to assessfrom satellites, and information on their status hasbeen scattered, anecdotal, and relatively inaccessible.The state of knowledge began to improve in 1988,when the World Conservation Monitoring Centre(WCMC) completed work on a three-volume collectionof preliminary reports on coral reef problems in 108nations, which was published by the United NationsEnvironment Programme and the World ConservationUnion. In 1993, ReefBase, a global database on coralreefs, was established by the International Center forLiving Aquatic Resources Management (ICLARM), andWCMC. This resulted in the first global map depictingthe location of shallow reefs around the world, pub-lished by WCMC in 1996. Eighty nations now partici-pate in a Global Coral Reef Monitoring Network, toassess the health of reef ecosystems. This network andother efforts will provide a clearer picture of the impactof human activities on coral reefs. However, it will takeyears to assemble a comprehensive picture of the statusof reefs based on field research.

Reefs at Risk: A Map-based Indicator of Threats to theWorld’s Coral Reefs provides the first map-based globalanalysis of the condition of coral reefs. As such, itmarks a significant advance in understanding the con-dition of coral reefs and should help stimulate furtherdata gathering that will improve subsequent reporting.This study draws on 14 global datasets that are indica-

tors of development pressure, information on 800ReefBase sites that are known to be degraded, plus sci-entific expertise—to model areas where existing humanpressures indicate that reefs are threatened by sedimen-tation, pollution, overfishing, and other factors.

The analysis offers a stark warning: the pressure ofhuman activities poses grave danger to reefs in most ofthe world’s oceans, and irreparable damage is occur-ring rapidly. The exceptions are places still isolatedfrom intense human pressures and those few placesthat have implemented effective measures to protectreefs. That is the key. Action is needed, and action ispossible to protect these treasuries of ocean wealth.

Many of the protective measures needed to ensurethe health of these ecosystems are “win-win” optionsfor both reefs and people. For example, creatingmarine parks and sanctuaries may enrich local com-munities by attracting tourists and may benefit near-by fisheries by protecting breeding stock of targetspecies. Eliminating perverse and often costly subsi-dies to fisheries and agriculture, for example, mayreduce overfishing, sedimentation, and pollution ofreefs, and building sewage treatment facilities withincoastal communities may provide both environmen-tal and health benefits.

We deeply appreciate support for this project fromthe United Nations Environment Programme, theSwedish International Development CooperationAgency, the David and Lucile Packard Foundation,the Bay Foundation, the Henry Foundation, and theU.S. Environmental Protection Agency.

Mark Collins Meryl J. WilliamsChief Executive Director GeneralWCMC ICLARM

Jonathan LashPresident

World Resources Institute


Foreword

This report presents the first-ever detailed, map-basedassessment of potential threats to coral reef ecosys-tems around the world. “Reefs at Risk” draws on 14data sets (including maps of land cover, ports, settle-ments, and shipping lanes), information on 800 sitesknown to be degraded by people, and scientificexpertise to model areas where reef degradation ispredicted to occur, given existing human pressureson these areas. Results are an indicator of potentialthreat (risk), not a measure of actual condition. Insome places, particularly where good management ispracticed, reefs may be at risk but remain relativelyhealthy. In others, this indicator underestimates thedegree to which reefs are threatened and degraded.Our results indicate that:

■ Fifty-eight percent of the world’s reefs are poten-tially threatened by human activity—rangingfrom coastal development and destructive fishingpractices to overexploitation of resources, marinepollution, and runoff from inland deforestationand farming.

■ Coral reefs of Southeast Asia, the most species-rich on earth, are the most threatened of anyregion. More than 80 percent are at risk (undermedium and high potential threat), and over halfare at high risk, primarily from coastal develop-ment and fishing-related pressures.

■ Overexploitation and coastal development posethe greatest potential threat of the four risk cate-gories considered in this study. Each, individually,affects a third of all reefs.

■ The Pacific, which houses more reef area than anyother region, is also the least threatened. About60 percent of reefs here are at low risk.

■ Outside of the Pacific, 70 percent of all reefs areat risk.

■ At least 11 percent of the world’s coral reefs con-tain high levels of reef fish biodiversity and areunder high threat from human activities. These“hot spot” areas include almost all Philippine

reefs, and coral communities off the coasts ofIndonesia, Tanzania, the Comoros, and the LesserAntilles in the Caribbean.

■ Almost half a billion people—8 percent of thetotal global population—live within 100 kilome-ters of a coral reef.

■ Globally, more than 400 marine parks, sanctuar-ies, and reserves (marine protected areas) containcoral reefs. Most of these sites are very small—more than 150 are under one square kilometer insize.

■ At least 40 countries lack any marine protectedareas for conserving their coral reef systems.


KEY FINDINGS

Although they occupy less than one quarter of 1 percent of the marine environment, coral reefs arehome to more than a quarter of all known marinefish species.1 These habitats have been called the rainforests of the marine world: highly productive,rich in species, and—because they predominate inmany regions noted for extreme poverty and highpopulation growth rates—particularly vulnerable to future degradation.

Seventy percent of the planet is covered by oceans,yet humans have barely begun to catalog the biotafound within marine environments. Over recentdecades, scientists, policy-makers, and the publichave become increasingly aware of the magnitude of destruction of terrestrial habitats, especially thebiologically rich tropical rainforests, and the need to stem the onslaught of human pressures onremaining natural places. Knowledge has proved keyto raising awareness: by at least roughly gauging—through such figures as deforestation rates and esti-mates of species loss—the extent and magnitude ofhuman impact on terrestrial biodiversity, scientistshave demonstrated what is at stake should poorlyplanned development continue unchecked.

Midway through the 1998 “Year of the Ocean” and following the 1997 “Year of the Reef”—two campaigns aimed at raising global awareness of the importance of our marine heritage—we still lack comprehensive estimates regarding the status of, and the magnitude of threats to, these aquaticecosystems. In terms of addressing knowledge gaps,coral reefs are a priority because of their extraordinar-ily high biological richness and the multitude of products and ecosystem services they provide to human beings.

This report presents a detailed, map-based analysis ofthreats to (and pressures on) the world’s coral reefs.Until now the only information on the status ofcoral reefs worldwide was an estimate, first publishedin 1993, which indicated that 10 percent of theworld’s reefs were dead, and that 30 percent were likely to die within 10 to 20 years.2 These fig-ures, which have since been widely quoted, were

based on guesswork by a number of scientists and onanecdotal evidence. Reefs at Risk—the first systematicand data-driven global assessment of these habitats—confirms that coral reefs are seriously threatened inmost parts of the world. The maps in this report provide a detailed picture of where reefs are in jeopardy, identify reefs at risk that are of high biodiversity value, and show where reefs lack protec-tion through parks, sanctuaries, and reserves.

Our results serve as an indicator of the threats to theseecosystems, not as an actual measure of degradation.Scientists do not know the actual condition of thevast majority of the world’s reefs. In the Pacific, forexample, 90 percent of the coral reefs have neverbeen assessed.3 In the absence of complete informa-tion on reef condition, we have drawn together avail-able global maps and other data sets that measurehuman activity and, using a geographic informationsystem and more than 800 mapped ReefBase sites*known to be degraded by humans, have modeledareas where one might predict degradation to occur,given existing anthropogenic pressures on the land-and seascape. Reefs at Risk draws on 14 distinct datasets and the input of coral reef experts and scientistsfrom around the world.


INTRODUCTION

*ReefBase—a database produced by the International Center forLiving Aquatic Resources Management—is the most comprehen-sive source of global information available on coral reefs.


Coral reefs are among the most valuable ecosystems on earth because of their

immense biological wealth and the economic and environmental services they

provide to millions of people. According to one estimate, reef habitats provide

humans with living resources (such as fish) and services (such as tourism returns and

coastal protection) worth about $375 billion each year.4

What Is at Stake?REEFS AND PEOPLE:

Coral reefs are important for the following reasons:

Biodiversity: Coral reefs are among the most biologi-cally rich ecosystems on earth. About 4,000 species offish and 800 species of reef-building corals have beendescribed to date.5 However, experts have barely begunto catalog the total number of species found within

these habitats. One prominent scientist, MarjorieReaka-Kudla, estimates there may be between one andnine million species associated with coral reefs.* Usingthis figure and rough estimates of human-caused reefdegradation, Dr. Reaka-Kudla projected that over a mil-lion of these species may face extinction within thecoming four decades.6

Likened to the tropical rainforests, coral reefs possess a wealth of diversity.

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Reef-associated plants and animals provide people with:

Seafood: Much of the world’s poor, most of whom arelocated within the coastal zones of developing regions,depend directly on reef species for their protein needs.Globally, one-fifth of all animal protein consumed byhumans comes from marine environments—an annualcatch valued at $50 billion to $100 billion.12 In devel-oping countries, coral reefs contribute about one-quar-ter of the total fish catch, providing food, according toone estimate, for one billion people in Asia alone.13, 14 Ifproperly managed, reefs can yield, on average, 15 tonsof fish and other seafood per square kilometer per year.However, in many areas of the world, fishers are deplet-ing this resource through overexploitation and destruc-tive fishing practices. According to a World Bank esti-mate, Indonesia forfeits more than $10 million a year

in lost productivity, coastal protection, and other bene-fits through large-scale poison fishing alone. Throughcareful management, these reefs could support a $320 million industry, employing 10,000 Indonesianfishers.15

New medicines: In recent years, human bacterial infec-tions have become increasingly resistant to existingantibiotics. Scientists are turning to the oceans in thesearch for new cures for these and other diseases. Coralreef species offer particular promise because of thearray of chemicals produced by many of these organ-isms for self-protection. This potential has only barelybeen explored. Corals are already being used for bonegrafts, and chemicals found within several speciesappear useful for treating viruses. Chemicals withinreef-associated species may offer new treatments forleukemia, skin cancer, and other tumors.16 According toone estimate, one-half of all new cancer drug researchnow focuses on marine organisms.17, 18

Other products: Reef ecosystems yield a host of othereconomic goods, ranging from corals and shells made


Coral reefs resemble tropical rainforests in two ways: both thriveunder nutrient-poor conditions (where nutrients are largely tiedup in living matter), yet support rich communities through incred-ibly efficient recycling processes. Additionally, both exhibit veryhigh levels of species diversity. Coral reefs and other marineecosystems, however, contain more varied life forms than do landhabitats. All but one of the world’s 33 phyla (major kinds oforganisms) are found in marine environments—15 exclusively so.7

Coral reefs are noted for some of the highest levels of total(gross) productivity on earth. Coral polyps—the thin livinglayer covering reef structures—provide much of the energythat fuels these communities. These tiny animals containalgae, which convert sunlight to fuel, deriving nutrients frompolyp wastes in the process. Reef-building corals and certaincalcareous algae (which may constitute more than half of areef’s stony substance) lay down a foundation of calcium car-bonate. Over generations this accumulation results in oftenmassive structures, providing homes and hiding places forcountless other creatures. Coral reefs, then, are the net resultof thousands of years of growth. As such, many are among theplanet’s oldest living communities.

In general, coral reefs are found in shallow waters,between the Tropic of Capricorn and the Tropic of Cancer.

Their total extent is unknown, although it probably exceeds600,000 square kilometers.8 The World ConservationMonitoring Centre recently mapped the global distributionof shallow reefs (the base maps for this study). Using thesedata, Mark Spalding and A. M. Grenfell estimated the totalglobal area of near-surface reefs (these being the mostdiverse, productive and economically important reefs) to be some 255,000 square kilometers.9 Coral reefs repre-sent less than 0.2 percent of the total area of oceans (andcover an area equivalent to 4 percent of the world’s crop-land area).

Levels of species diversity vary within these ecosystems,depending on location. The most species-rich reefs are foundin a swath extending through Southeast Asia to the GreatBarrier Reef, off northeastern Australia. More than 700species of corals alone are found in this region. Within theGreat Barrier Reef, 1,500 species of fish and 4,000 speciesof mollusks have been counted. Reefs outside this region areimportant for the distinct populations and species they con-tain. For example, although fewer types of corals are found inthe Red Sea, this basin contains more endemics (speciesfound nowhere else) than other portions of the EasternIndian Ocean.10, 11

Coral Reef Ecosystems

* Reaka-Kudla’s figures may be high. Scientists who helped preparethe Global Biodiversity Assessment (United Nations EnvironmentProgramme, 1992) estimated that there are perhaps 14 millionspecies altogether, counting those within land and aquatic environ-ments. Others suggest even greater diversity is possible, when micro-bial life is fully considered.

into jewelry and tourism curios to live fish and coralsused in aquariums, to sand and limestone used by theconstruction industry. However, such extractive activi-ties are usually damaging to these habitats.

Coral reefs offer a wide range of environmental ser-vices, some of which are difficult to quantify, but are ofenormous importance to nearby inhabitants. These ser-vices include:

Recreational value: The tourism industry is one of thefastest growing sectors of the global economy. Coralreefs are a major draw for snorkelers, scuba divers,recreational fishers, and those seeking vacations in thesun (some of the finest beaches are maintainedthrough the natural erosion of nearby reefs). More than100 countries stand to benefit from the recreationalvalue provided by their reefs. Florida’s reefs pump $1.6 billion into the economy each year from tourismalone.19 Caribbean countries, which attract millions of

visitors annually to their beaches and reefs, derive, onaverage, half of their gross national product from thetourism industry, valued at $8.9 billion in 1990.20

Coastal protection: Coral reefs buffer adjacent shore-lines from wave action and the impact of storms. Thebenefits from this protection are widespread, and rangefrom maintenance of highly productive mangrove fish-eries and wetlands to supporting local economies builtaround ports and harbors, where, as is often the case inthe tropics, these are sheltered by nearby reefs.

Globally, we estimate almost half a billion people livewithin 100 kilometers of a coral reef, benefiting fromthe production and protection these ecosystems pro-vide (see Figure 1). A recent study found that the costsof destroying just one kilometer of reef range fromabout $137,000 to almost $1.2 million over a 25-yearperiod, when fishery, tourism, and protection valuesalone are considered.21


Complex chemistry—the clownfish is immune to and protected by thestinging tentacles of the sea anemones.

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Diving and snorkeling allow up-close viewing of some of the wondersof the undersea world.

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Pacific

Southeast Asia

Indian Ocean

Middle East

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FIGURE 1. Almost Half a Billion People Live Near ReefsNumber of People Within 100 km. of a Coral Reef

Millions

Coral reefs around the world are

threatened by an onslaught of

human activities. These include:

Effects of coastal development: The growth ofcoastal cities and towns generates a range of threats tonearby coral reefs. Where space is limited, airportsand other construction projects are built upon reefcommunities. Dredging of harbors and shippingchannels and the dumping of spoils result in the out-right destruction of these habitats. In many areas,coral ecosystems are mined for construction materi-als—sand and limestone, which is made intocement—for new buildings.

The indirect effects of development are the mostdamaging. Reef-building corals—specifically the algae(zooxanthellae) within their coral polyps, which gener-ate energy through photosynthesis—require sunlit

waters to survive. Algal blooms resulting from excessnutrients that come from sewage releases and othersources block sunlight, reducing coral growth.Shoreline construction and modification disturbs sedi-ments, which smother corals. Nutrient-rich runoff pro-motes the growth of bottom-dwelling algal competitorsand interferes with coral reproduction. Other threatsinclude hot-water discharges from power plants, andmine runoff and industrial toxic waste effluents, whichpoison reef communities.22, 23, 24

Even tourism, where it is unregulated, can pose athreat. Swimmers and divers in the Gulf of Aqaba(bounded by Saudi Arabia, Jordan, Israel, and Egypt),for example, have destroyed corals through trampling,while boat anchors create further damage to someareas.25 In many other places, hotels and resorts dis-charge sewage directly into the ocean, polluting reefwaters and promoting algal growth. Demand for foodfish and tourism curios results in overfishing of keyreef species.


THREATS TO REEFS

Nutrient pollution and sediments from coastal development canblock sunlight, essential for coral growth.

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Overexploitation and destructive fishing practices:Although measured together in the Reefs at Risk indica-tor, overexploitation and destructive fishing can be sep-arated into two types of threats.

Overexploitation affects the vast majority of theworld’s reefs. (See box “Overfishing of Target Species.”) Ata minimum, overfishing results in shifts in fish size,abundance, and species composition within reef com-munities. Evidence suggests that removal of key herbi-vore and predator species may ultimately affect large-scale ecosystem changes. For example, removal of trig-gerfish has been linked with explosions in burrowingurchin populations, their prey, who subsequently accel-erate reef erosion through feeding activities.

In the Caribbean, decades of overfishing has led, inmany places, to very low levels of grazing fish species.Because of this, herbivorous sea urchins (a nonburrow-ing species) have played an increasingly important rolein keeping down algal growth. In the early 1980s, hugenumbers of these urchins succumbed to disease.Without grazing fish or urchin populations, andspurred on in many areas by organic pollution, algaequickly dominated the reefs, inhibiting coral settlementand sometimes overgrowing living corals. In areas such

as Jamaica, hurricanes further compounded the dam-age, reducing coral to rubble. Formerly thriving reefswere replaced by low-diversity and low-productivityalgal systems. Some scientists claim this is a harbingerof events to come, as reefs around the world continueto be overfished. Others argue that these major ecosys-tem effects may be reversible in the short term, ifdegradation has not gone too far.26, 27, 28, 29

Destructive fishing: Blast fishing; fishing with cyanideand other poisonous chemicals; muro-ami netting(pounding reefs with weighted bags to scare fish out ofcrevices); and in deeper waters, trawling directly dam-age corals. Because these methods are generally nonse-lective, large numbers of other species, along withundersized target species, may be swept up in nets orkilled by poisons or explosives in the process. (See box“Cyanide Fishing.”) As not all fishing methods aredestructive, this is less of a widespread threat than over-exploitation.

Impact from inland pollution and erosion: Sediment,pesticides, and pollution from human activities inlandcan damage coral reefs when transported by rivers intocoastal waters. These result in the smothering of corals,


The live fish trade is leaving many reefs devoid of showcase species.

Pollution and erosion from land-clearing activities far inland contribute to reef sedimentation.

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reduced light levels (affecting growth), andovernutrification of reef communities.Pollution is a particular threat to coral reefsnear the mouths of small and medium-sized watersheds, as the high volume offreshwater flow and sediments carried bymajor rivers naturally inhibits coral growth.Land clearing can expand the extent of thisno-growth zone. Watersheds cleared of theirforests and other vegetation cover are vulnerable to erosion and flooding. Duringhigh water periods, silt and pollutants with-in these basins are carried far beyond thenormal “plume,” or the area where coralreef growth would normally be limited byriver discharges, had they been intact.30, 31

Marine-based pollution: In comparison tothe other stresses, oil spills and the deliberatedischarge of oily ballast water by passing


Many reef species, including giant clams, sea cucumbers,sharks, lobsters, large groupers, snappers, and wrasses, arenow fetching high prices both on domestic markets and inter-nationally. In order to capture these “target species,” commer-cial fisheries operations are moving further and further afield,and now regularly visit even the most remote reefs in theworld. In many areas such harvesting is clearly unsustainable.

Fishers sweep reefs of their valuable species and thenmove on, eliminating entire populations within the areas theyleave behind. Two examples from the Philippines illustrate thisthreat. During the 1960s and 1970s, several giant clamspecies became locally extinct due to overharvest for foodand for their large shells, which are popular as decorations,sinks, and bird baths. As recently as 1987, the sea urchinTripneustes gratilla was found in dense populations across a24-square-kilometer sea grass bed on a reef flat in Bolinao.Exploitation rates increased suddenly with the appearance ofa trader from China and by 1995 the sea urchin was believedto have become locally extinct.32

There are increasing reports of buyers for specialtymarkets appearing in reef areas and overfishing species tolocal extinction. Sea urchin and sea cucumber havereportedly disappeared from certain reefs in theGalapagos and the western Caribbean. Concerns aboutthe overexploitation of sea horses for Chinese medicineand the aquarium trade have prompted the initiation ofsuccessful projects in the Philippines to educate villagers

to properly manage the wild stocks and to grow sea horsesfor controlled export.

A very obvious change to many of the world’s reefs is thelack of large, predatory fish. A long-standing symbol of coralreefs, the large grouper is becoming a rarity. Much of theproblem is related to the ease with which these often verysociable fish can be shot with spear guns. Rampant blast fish-ing has also contributed to their demise. The capture of sharksfor sharkfin soup and other products has made sharks rare onmany reefs, especially in the Southeast Asian region. Of par-ticular importance is the loss of large reef fish in connectionwith the live fish trade supplying Chinese restaurants. Thistrade has led to widespread reductions of populations ofgroupers, humphead wrasses, and others.33

Experts contributing to the Reefs at Risk study concluded,during a 1997 mapping workshop held in Manila, that targetspecies fishing now occurs on most of the world’s reefs. Thisfact was confirmed during the recent Reef Check volunteersurvey covering hundreds of reefs around the world, whichshowed that even some of the most isolated reefs on the planet are affected. Because this activity is so widespread anddifficult to document, the threat of target species overfishingis underrepresented in the Reefs at Risk indicator. Although,to date, few marine species are known to have become com-pletely extinct, the important message is that because of thepervasive nature of this threat, very few reefs can truly be con-sidered pristine.

Overfishing of Target Species

Destructive fishing practices, such as the use of cyanide, and overfishing pose thegreatest threats to the integrity of coral reefs.

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When corals undergo certain kinds of stress, much of thezooxanthellae—the symbiotic algae that provide coral polypswith nutrients—are expelled from the coral tissue. Ultimately,weakened corals may die. Bleaching is a frequent symptom ofpollution-induced stress, as well as a response to natural fac-tors such as changes in water temperature, salinity levels, andpossibly ultraviolet light.34

During the El Niño of 1982–83, large areas of coral reefaround the world were severely damaged by high water tem-peratures, which resulted in coral bleaching. Scientific studieshave linked bleaching events to temporary “hot spots,” localareas of unusually high temperatures caused by changes inatmospheric circulation during the El Niño oceanographicevents. (Map 1 provides a sense of the wide incidence of coralreef bleaching.) The effects of the severe El Niño that startedin 1997 have yet to be documented.

35, 36

Coral ReefBleaching

Coral bleaching occurs rapidly in response to a wide range ofstresses.

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ships pose an unknown, but probably less significant,threat to coral reefs. Studies on the impact of some 8–9million barrels of oil discharged into the Arabian Gulfduring the Iran–Iraq and Gulf Wars found that spillsappeared to be related to short-term declines in many fish

and other species. In 1986, a major spill off the mouth ofthe Panama Canal was linked by scientists to significantlosses of coral diversity and cover in heavily affected areas.In the longer term, oil spills may leave reef communitiesmore vulnerable to other types of disturbances.37, 38, 39

MAP 1.

In many cases it is difficult to pinpoint the exactcauses of coral reef declines now occurring around theworld. Scientists believe that degradation frequentlyoccurs through the interaction of a combination ofhuman-caused factors, which then leaves reef commu-nities less resistant to periodic natural disturbances.Disease, temperature extremes, pest outbreaks, tropicalcyclones, and other natural events periodically devas-tate corals, with resulting ecosystem-wide repercus-sions. However, healthy reefs are resilient, and willrecover with time. The impact of multiple stressors,both natural and human caused, can have a multiplica-tive effect on reef ecosystems. Evidence, much of itanecdotal, suggests that human-damaged reefs may bemore vulnerable to some types of natural disturbancesand take longer to recover.40 For example, some expertsbelieve pollution contributed to the recent die-offs ofFlorida Key reefs in the United States from white poxdisease.41

Even where they are not directly affected byhuman activity, coral reefs may be threatened by the

degradation of nearby mangroves, seagrass beds, and other associated habitats, which serve as nurs-eries for many reef species. In addition, mangrovesplay an important role in filtering out sedimentswashed into coastal areas from upstream runoff.In many parts of the world, mangroves are beinghacked away for fuel wood, creation of aqua-ulture ponds, and to make room for coastal development.42, 43

One other long-term threat is global climatechange. Current models predict that climate changewill elevate sea surface temperatures in many places,cause sea levels to rise, and result in greater frequencyand intensity of storms. Although regional and localpatterns in these changes are harder to model, theeffects on coral reefs are likely to include greater physi-cal damage by storms and more frequent instances ofcoral bleaching. (See box “Coral Reef Bleaching.”) Thisincrease in “natural” stress levels will leave coral reefsin many parts of the world more vulnerable to humandisturbances.44


The use of cyanide to stun and capture live coral reef fishbegan in the 1960s in the Philippines to supply the growingmarket for aquarium fish in Europe and North America, amarket now worth more than $200 million a year. Since thelate 1970s, the poison has also been used to capture largerlive reef fish (primarily grouper species) for sale to specialtyrestaurants in Hong Kong and other Asian cities with largeChinese populations. Selected and plucked live from a restau-rant tank, some species can fetch up to $300 per plate, andare an essential status symbol for major celebrations and busi-ness occasions. As the East Asian economy boomed over thepast several decades, live reef food fish became a businessworth some $1 billion annually.

Despite the fact that cyanide fishing is nominally illegal in vir-tually all Indo-Pacific countries, the high premium paid for livereef fish, weak enforcement capacities, and frequent corruptionhave spread the use of the poison across the entire region—home to the vast majority of the planet’s coral reefs. Since the1960s, more than one million kilograms of cyanide has beensquirted onto Philippine reefs, and the vast Indonesian archipel-ago now faces an even greater cyanide problem. As stocks inone country are depleted, the trade moves on to new frontiers,

and cyanide fishing is now confirmed or suspected in countriesstretching from the central Pacific to the shores of East Africa.Sadly, the most pristine reefs, far from the usual threats of sedi-mentation, coral mining, and coastal development, are the pri-mary target for cyanide fishing operations.

Systematic scientific testing of the impact of cyanide onreefs is scanty, but tests show that cyanide kills corals, and itstoxic effects on fish are well known. Anecdotal evidence ofthe poison’s lethal effects on the reef comes from countlessscuba-diving operators, field researchers, and cyanide fisher-men themselves. The process of cyanide fishing itself indis-putably wreaks havoc on coral reefs. The divers crush cyanidetablets into plastic squirt bottles of sea water and puff the solu-tion at fish on coral heads. The fish often flee into crevices,obliging the divers to pry and hammer the reefs apart to col-lect their stunned prey. Cyanide fishing also poses humanhealth risks: to fishermen, through accidental exposure to thepoison and careless use of often shoddy compressed-airdiving gear by untrained divers.

Cyanide fishing can be attacked, as experience shows in thePhilippines, the only country so far to take concrete actionagainst the problem. That country’s Cyanide Fishing Reform

Cyanide Fishing: A Poison Tide on the Reef

(continued on page 16)

Program, a unique partnership between the government andthe International Marinelife Alliance (IMA), a local non-gov-ernmental organization, has trained thousands of fishermen touse alternatives to cyanide such as fine-mesh barrier netsdraped over a reef section to catch aquarium-sized fish andhook-and-line techniques to catch larger fish for the restauranttrade. The government has stepped up enforcement of anti-cyanide fishing laws by establishing a network of cyanide detec-tion laboratories, operated by IMA, that randomly sample fishexports at shipment points throughout the country and monitorall aspects of the trade. New regulations are slated to maketesting a requirement for all live fish exports and to tighten con-trols on import and distribution of cyanide. A public awarenesscampaign in the media and public schools is helping to educateFilipinos about the value of coral reefs and the threats posed bycyanide and other destructive fishing practices. Cyanide fishing

has not ceased in the Philippines, but it has certainly beenreduced as a result of these efforts.

Currently, IMA, the World Resources Institute, and otherpartners are implementing the only on-the-ground program inIndonesia to train cyanide fishermen in alternative capturetechniques, and are collaborating in the Indo-PacificDestructive Fishing Reform Program to assist governments inat least half a dozen countries in Southeast Asia and the Pacificto combat this poison tide sweeping the planet’s largest andmost diverse expanse of coral reefs.

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MAP 2.

Our analysis covers potential threats from (1) coastaldevelopment, (2) overexploitation and destructive fish-ing practices, (3) the impact of inland pollution anderosion, and (4) marine pollution. This assessmentdoes not include likely future threats posed by popula-tion growth or climate change, nor does it considerthreats resulting from coral diseases, bleaching, andother factors considered largely natural in origin.

Our results are based on a series of distance relation-ships correlating mapped locations of human activitysuch as ports and towns, oil wells, coastal mining activi-ties, and shipping lanes (“component indicators”), withpredicted risk zones of likely environmental degrada-tion. Detailed subnational statistics on population den-sity, size of urban areas, and land cover type were alsoincorporated into the analysis. In addition, we useddata on rainfall and topography to help estimate poten-tial runoff within watersheds, from inland deforestation(and other land clearing), and from agriculture.

Distance rules defining threat zones were establishedfor each component indicator using information on theknown locations of more than 800 reef sites docu-mented as degraded by human activity by one of thefour factors (for example, coastal development) consid-ered in this analysis. Minimum distances were estab-lished through expert review and input, and by deter-mining the most conservative set of rules that, whentaken in aggregation for any one of the four threat cate-gories, assured that we encompassed at least two-thirdsof all known degraded sites affected by activities relatedto that category. Tables 1 and 2 present the componentindicators used and the decision rules established tograde any one reef as under “low,” “medium,” or “high”threat. (A more detailed description of the implementa-tion of the Reefs at Risk Indicator can be found in theTechnical Notes at the end of this publication.)

Draft risk maps were revised and vetted at a globalworkshop attended by coral reef experts from around the


THE REEFS ATRISK INDICATOR

“R eefs at Risk” is an indicator: it flags problem areas around the world

where, in the absence of good management, coral reef degradation might

be expected, or predicted to occur shortly, given ongoing levels of human

activity. Such degradation includes major changes in the species composition, relative species

abundance, and/or the productivity of coral reef communities, attributable to human distur-

bance. As noted above, this indicator measures potential risk associated with human activity,

not actual reef condition.

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THREAT FACTOR: COASTAL DEVELOPMENT

Component Indicator Qualifier High Medium

Cities population over 5 million within 30 km 30–60 kmCities population over 1 million within 20 km 20–40 kmCities population over 100,000, with

little sewage treatment within 10 km 10–25 kmCities population over 100,000, with

moderate sewage treatment — within 10 kmSettlements any size — within 8 kmAirports and military bases military and civilian airports — within 10 kmMines any type within 10 km —Tourist resorts including diving facilities — within 8 km

THREAT FACTOR: MARINE POLLUTION


Ports large size within 20 km within 50 kmPorts medium size within 10 km within 30 kmPorts small size — within 10 kmOil tanks and wells any size within 4 km within 10 km“Shipping threat areas” known major shipping

routes with areas of relativelynarrow passage — defined zone

THREAT FACTOR: OVEREXPLOITATION AND DESTRUCTIVE FISHING


Population density coastal population density within 20 km —exceeds 100 persons per sq. km.

Population density coastal population density — within 20 kmexceeds 20 persons per sq. km.

Destructive fishing expert-defined areas where blast or cyanide fishing occur within 20 km —

THREAT FACTOR: INLAND POLLUTION AND EROSION


Modeled relative erosion based on the relative slope, scaled to modeled river flow scaled to modeled river flowpotential (REP) land cover class, and

precipitation in an area

Notes:Table 1 defines zones for high and medium threat only. Areas notdefined as under high or medium threat default to low threat.

Within the coastal development threat factor, areas classified asbeing under medium threat from any individual component thatwere also identified as an embayment or lagoon were reclassifed tohigh threat to reflect the elevated threat to reefs in enclosed waters.

Within the overexploitation threat factor, only countries where theper capita gross national product is less than $10,000 per year or theper capita fish consumption is greater than 50 kilograms per personper year were included.

Further description of the methodology can be found in theTechnical Notes at the back of this publication.

TABLE 1. REEFS AT RISK INDICATOR: DECISION RULES FOR COMPONENT INDICATORS

world. At that workshop, scientists also mapped areasunder high threat from destructive fishing practices, andareas of intense shipping within narrow passages or“shipping threat areas”—two additional data setsincorporated into this analysis. Final draft mapsunderwent a second series of review by these andother experts. (Experts who helped us with the map-ping or otherwise contributed to this study are listedin the acknowledgments.)

Overall, the Reefs at Risk indicator accurately classi-fies over 80 percent of sites known to be degraded byhumans as “at risk.”* In some cases, where we knowthe condition of reefs, those mapped as at risk never-theless remain relatively healthy due to good planningand management by local governments and people, orbecause currents, topography, and other factors renderthese reefs less sensitive to the impact of human acti-vity. In other cases, a review of the literature and expertopinion show that degradation is actually worse thanour indicator suggests. (Experts’ comments on the finalReefs at Risk Indicator results can be found in theTechnical Notes.)

Finally, it is important to note that reefs classified asbeing at low risk are not necessarily healthy: these sites

may be affected by pressures not captured by this indi-cator (overfishing within remote areas, undocumentedby our experts), or by new activities not captured byour base maps and statistics, many of which are alreadyout-of-date (for example, development of a new mineor sedimentation from newly cleared land upstreamfrom a reef). For these reasons, we have likely under-reported risk in regions where the availability of recenthigh-quality data is poor and in areas, such as portionsof the Pacific, where many reefs are distant fromhuman settlements. The maps presented here are a static picture of pressures on reefs: sites at low risktoday may be under heavy pressure, and as a result beseriously degraded, within the next few years.


TABLE 2. CLASSIFICATION RULES FOR RANKING RISK

Data reflecting coral reef locations were initially classified by indi-vidual threat factors and finally by the combined (integrated)results for all four threat factors as follows:

Reefs classified as high threat in at least one of the threat factorsare assigned High Threat overall;

Reefs classified as medium threat in at least one threat factor areassigned Medium Threat overall; and

Reefs classified as low threat in all four threat factors are assignedLow Threat overall.

* We compared Reefs at Risk results with 800 sites documented with-in ICLARM’s ReefBase (version 2) database as having been degradedby human activity. This analysis showed that 80 percent of the time,our results accurately classified these areas as “at risk” (under medi-um or high threat).

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These figures are tempered by the relatively low threatfaced by coral reefs in the Pacific—home to more reefsthan any other part of the world. Forty-one percent ofreefs in the Pacific are estimated to be at risk. Outsideof this region, 70 percent of all reefs are at risk (almost40 percent at high risk). Figure 4 presents a summaryof coral reef area and combined threat classification by

region, while Figure 5 shows the same information forseveral countries. (Definitions for regional groupingscan be found in the Technical Notes section.)


STATUS OF THEWORLD’S CORAL

REEFS

Over- Exploitation

Coastal Development

Inland Pollution

Marine- Based Pollution

5%

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Medium Threat

High 27%

67,900 sq. km

Medium 31%

79,000 sq. km

Low 42%

108,400 sq. km

FIGURE 2. FIFTY-EIGHT PERCENT OF THE WORLD’SREEFS ARE AT RISK

More than a quarter of the world’s reefs are at high risk, and just under a third

of these habitats are at moderate risk, from human disturbance. Of the four

broad categories of potential threat to coral reefs evaluated, overexploitation

of marine resources, including destructive fishing practices, and coastal development present

the greatest threat. Globally, 36 percent of all reefs were classified as threatened by overex-

ploitation, 30 percent by coastal development, 22 percent by inland pollution and erosion,

and 12 percent by marine pollution. When these threats are combined, 58 percent of the

world’s reefs are at risk (defined as medium and high risk). (See Figures 2 and 3.)

FIGURE 3. OVEREXPLOITATION AND COASTALDEVELOPMENT POSE THE GREATEST THREAT TO REEFS

Percentage of Reefs at High, Medium and Low Risk

Percentage of Global Reefs at Risk by Individual Threat Factors

Note: Figures 2 and 3 are based upon coral reef area totals (equaling255,000 square kilometers) derived from the World ConservationMonitoring Centre base maps used in this study.

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A. Regional Statistics

B. Selected Country and Geographic Grouping Statistics

a. Reef Area Estimates by Region and Threat Category (sq. km.) and percentagesReef area estimates are based on WCMC’s dataset Shallow Coral Reefs of the World and Spalding and Grenfell (1997).Estimates of shallow reef area for Australia, Indonesia and the Philippines are significantly smaller than other published estimates.

b. Average Coastal Population Density (pp/sq.km. )Statistics are for populated areas within 60 kilometers of the coastline. Population data come from Gridded Population ofthe World data set from the National Center for Geographic Information and Analysis — Global Demography Project. Data are unavailable for some small island areas.

c. Marine Protected Areas (Number and Area Estimates)Marine protected area counts and area estimates are summaries of the WCMC data set Marine Protected Areas of the World, and are incomplete for some countries. Area statistics for protected sites are for the entire protected area, which include non-reef areas and can include substantial land areas.

Reef Area in Square Kilometers Percentages Coastal Population

Coastal Population

Marine By Threat Categorya Densityb Protected Areasc

Region Total Low High Low MediumMedium

MediumMedium

High Number Area (sq. km.)

Middle East 20,000 7,800 9,200 3,000 39% 46% 15% 24 10 11,845

Caribbean 20,000 7,800 6,400 5,800 39% 32% 29% 63 139 38,914

Atlantic (excl. Caribbean) 3,100 400 1,000 1,700 13% 32% 29% 64 3 368

Indian Ocean 36,100 16,600 10,500 9,000 46% 29% 25% 135 66 15,100

Southeast Asia 68,100 12,300 18,000 37,800 18% 26% 56% 128 57 36,263

Pacific 108,000 63,500 33,900 10,600 59% 31% 10% 98 92 372,809

Global Total 255,300 108,400 79,000 67,900 42% 31% 27% 101 367 475,298

Reef Area in Square Kilometers Percentages MarineBy Threat Categorya Densityb Protected Areas

Region Total Low High Low High (pp/sq.km.) Number Area (sq. km.)

Australia 48,000 33,700 13,700 600 70% 29% 1% 12 374,967

Fiji 10,000 3,300 4,800 1,900 33% 48% 19% 91 1

French Polynesia 6,000 4,900 1,100 0 82% 18% 0% 38 124

India 6,000 1,400 500 4,100 23% 8% 68% 241 288

Indonesia 42,000 7,000 14,000 21,000 17% 33% 50% 39 30,405

Lesser Antilles 1,500 0 300 1,200 0% 20% 80% 159 253

Maldives 9,000 7,900 1,100 0 88% 12% 0% NA NA

Marshall Islands 6,000 5,800 200 0 97% 3% 0% NA 163

New Caledonia 6,000 5,000 800 200 83% 13% 3% 6 530

Papua New Guinea 12,000 6,000 4,500 1,500 50% 38% 13% 7 2,149

Philippines 13,000 50 1,900 11,050 0% 15% 85% 174 458

Saudi Arabia 7,000 2,500 4,100 400 36% 59% 6% 15 4,500

Solomon Islands 6,000 3,000 2,500 500 50% 42% 8% 8 0

US - Hawaii 1,200 650 450 100 54% 38% 8% 50

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Most disturbing is the status of reefs in SoutheastAsia—a global hot spot of coral and fish diversity (seebox “Biodiversity and Reefs at Risk”). As with tropicalrainforests in this region, reef ecosystems are undertremendous threat. More than 80 percent of theseecosystems are potentially at risk, primarily fromcoastal development, overfishing, and destructive fish-ing practices.

Results from the Reefs at Risk analysis are presentedin Table 3 and in the five regional maps included inthis report. Regional highlights follow.

Caribbean and Atlantic Ocean: About 9 percent of theworld’s mapped reefs are found in this region, most ofwhich are located along the Central American coast andoff the Caribbean islands. Our results indicate that almosttwo-thirds of reefs here are at risk (about one-third at highrisk). Sedimentation from upland deforestation, poor agri-cultural practices, coastal development, pollution, andoverfishing are major threats to many reefs here.45, 46 Mostreefs of the Antilles and Lesser Antilles (including Haiti,the Dominican Republic, Puerto Rico, Dominica, andBarbados) are under high potential threat. Virtually all ofthe reefs of the Lesser Antilles are at risk. Almost all reefsof the Florida Keys are at moderate threat, largely fromcoastal development, inappropriate agricultural practices,overfishing of target species such as conch and lobster,and pollution associated with development and farming.Those of the Bahamas and the Yucatan Peninsula and theremoter reefs off Belize, Honduras, and Nicaragua arelargely at low risk from mapped human activity.

Indian Ocean: Over half of the region’s reefs are atrisk. Almost all of the reefs off India and Sri Lanka areunder high potential threat. Destructive fishing prac-

tices, overexploitation, pollution, sedimentation fromland clearings, and coral mining for lime have all beenblamed for the widespread degradation of Sri Lankanreefs.47, 48 Off East Africa, most documented damage tocoastal habitats occurs near major towns and cities, dueto sewage discharge and overexploitation. Blast fishingand agricultural runoff also pose significant threats.Our results indicate that the great majority of reefs ofthe Chagos Archipelago and Maldive Islands are underlow potential threat (according to this study, close to90 percent of reefs in the Maldives are at low risk). Alltold, the Indian Ocean accounts for roughly 15 percentof the world’s mapped reefs.

Middle East (Red Sea and Arabian Gulf): Although inthe past most of the region’s reefs have been reported tobe in good condition, about 60 percent of these habitatswere assessed as at risk primarily due to coastal develop-ment, overfishing, and the potential threat of oil spills inthe heavily trafficked Arabian Gulf and southern end ofthe Red Sea. Almost two-thirds of Gulf reefs are at risk,largely because over 30 percent of the world’s oil tankersmove through this area each year.49 Industrial pollutionand coastal development are threats in some areas.Corals in many parts of the Gulf of Aqaba have beendegraded through tourism impact and related develop-ment. Reefs in the northern Red Sea and the ArabianGulf are espe-cially vulnerable to degradation due tolimited water circulation and temperature extremes.About 8 percent of the world’s mapped reefs are foundin the Middle East.

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FIGURE 5. SIX COUNTRIES CONTAIN OVER HALF OF THEWORLD’S REEFS

100,000

120,000

Low

Medium

High

Middle East

Caribbean Indian Ocean

Southeast Asia

Pacific

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sFIGURE 4. MOST LOW RISK REEFS ARE IN THE PACIFIC

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Southeast Asia: Over 80percent of the reefs in thisregion are at risk, and overhalf (56 percent) are athigh risk. Most of the coralreefs of the Philippines,Sabah, Eastern Sumatra,Java, and Sulawesi wereassessed at high potentialthreat from disturbance.More than 70 percent of theregion’s people live withinthe coastal zone, puttingheavy pressure on nearbymarine resources.50

Overfishing, destructivefishing practices, sedimen-tation, and pollution asso-ciated with coastal develop-ment are the biggest threats.51

Southeast Asia contains one-quarter of the world’smapped reefs. Indonesia and the Philippines accountfor a major portion of these habitats. Reefs in bothcountries are noted for extraordinarily high levels ofdiversity, each containing at least 2,500 species of fish.52

Studies suggest that only 30 percent of reefs off bothcountries are in good or excellent condition (as mea-sured by live coral cover).53, 54 Our results, which includethreats from overfishing, indicate that virtually all ofPhilippine reefs, and 83 percent of Indonesia’s reefs, areat risk. Because of the reef area they contain, coastalzone policy and management decisions made by thesetwo countries will have a major impact on the globalheritage of coral reef diversity for future generations.

Pacific: Reefs here appear to be in the best shape of anyregion: almost 60 percent were assessed at low risk. About40 percent of the world’s mapped reefs are found in thePacific, many of which are located around remote atollsand within the Great Barrier Reef tract. Although reef com-munities in many uninhabited areas remain in good con-dition, others have been affected by the long-term impactsof historic nuclear testing and other military activities andby poaching of rare species.55 Several areas, particularlythose near population centers, face significant humanpressures. These include many of the reef communities off southeastern Papua New Guinea, the SolomonIslands, Vanuatu, Fiji, and Hawaii. Almost half of theHawaiian and Solomon Island reefs (the latter noted fortheir high biodiversity) are potentially threatened. Two-thirds of the reefs off Fiji are at risk. Overfishing, coastaldevelopment, logging, and agricultural erosion are docu-

mented threats to these ecosystems. Fiji’s reefs are animportant tourist draw and, according to a 1992 estimate,a major source of food for local people, generating closeto $200 million annually in fisheries and tourism revenues alone.56

Seventy percent of Australia’s reefs are at low risk.Although some parts of the inner Great Barrier Reef arepotentially threatened, good management has largelymaintained these as healthy ecosystems (see sectiontitled “Protecting the Health of Coral Reef Ecosystems”).


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R E E F S A T R I S K 11 R E E F S A T R I S K


Some threatened reefs stand out as particularly importantfrom a biodiversity perspective. As part of this analysis, weworked with collaborators at the University of York in England,and Ocean Voice International in Canada to integrate data onreef fish species diversity with our data on potential threats tocoral reefs. This allows for analysis of the likely degree ofthreat in areas of high reef fish richness—those having speciescounts in the top 20 percent of values found around the world.As noted below, our results are rudimentary, given the incom-pleteness of the fish species dataset.

At least 11 percent of the world’s reefs qualify as “biodiversityhot spots”: areas of high species richness that are also underhigh threat. As Map 3 shows in red, most of these sites arelocated in Southeast Asia (almost a quarter of this region’s reefsclassify), especially in waters off the Philippines, Indonesia, andJapan. As a proportion of total reef area, the Caribbeanemerges as another large hot spot: about 18 percent ofCaribbean reefs exhibit high coral reef fish species counts, andare at high risk. This includes most of the coral communities ofJamaica, Puerto Rico, and the Lesser Antilles (Guadeloupe,Dominica, Martinique, and other islands).*Additional hot spotareas were identified off the Comoros, Tanzania, and Fiji.

What does this imply, in terms of priorities for immediateprotection? Some scientists advocate taking a “portfolioapproach” to selecting new sites for protection as parks andreserves.57 They say that planners and managers should pro-tect important biodiversity sites that are threatened and siteswhere human pressure and human disturbance are low—where it is easier to create and maintain parks and reserves.About 17 percent of the world’s reefs exhibit high coral reeffish species richness, and are presently classified at low riskfrom human activities. More than half of these low-risk, high-diversity sites (shown in blue on the map) are located in thecentral and western Pacific, especially within waters offAustralia and Papua New Guinea. Large tracts of qualifying

reefs occur off the Maldives, Chagos Archipelago, Cuba, theBahamas, Belize, and southern Mexico.

It should be noted that there are many ways to defineimportant biodiversity areas beyond simply looking at totalspecies count (species richness). These include endemism (theproportion of species found nowhere else), the number andpercentage of rare species found, and protection of uniquetypes of coral reef communities (ecosystem representation),among others. An ideal assessment would examine conserva-tion importance at both the species level (examining endemicsand total species) and the ecosystem level (examining uniquehabitats). This analysis considers only total species count forone taxonomic group—coral fish species—and not the totalcount of all species. In choosing priorities for protection, manyplanners also consider nonbiological criteria, such as identify-ing sites to protect on the basis of economic and social val-ues.58 One major consideration in identifying conservation pri-orities is the degree to which sites are already protected asparks and reserves. Unfortunately, the data and maps used forthis analysis were too coarse to allow detailed examination ofprotected area gaps (existing marine protected area data arealso incomplete and/or are not adequately spatially refer-enced). Map 4 provides an idea of some of the possible gaps inprotection in Southeast Asia. Many areas in the Philippinesand Indonesia have high species diversity, are highly threat-ened, and are not protected.

*It should be noted that the analysis of areas of high reef fish biodiversity isbiased in favor of coral reef areas that are more intensively surveyed. Forexample, the analysis suggests that there are no hot spots in the MiddleEast, but, in fact, levels of biodiversity in parts of the Red Sea reach similarlevels to the hot spots in the Caribbean. Because a greater proportion ofspecies present in the Caribbean were sampled relative to other areas,these areas achieve relatively high species counts, warranting inclusion inthis analysis. Several other areas likely to have comparable diversity thatwere not included are the reefs off the coast of Vietnam and the SpratlyIslands.

Biodiversity and Reefs at Risk


Note: This map shows areas of known highreef fish species diversity (areas in excess of210 species), classified by estimated threat to rooks in that area.

MAP 3.

MAP 4.


Reef name: FLORIDA KEYS REEFSLocation: Southeastern United States

Description: These reefs extend from Miami to the Dry Tortugas, near Key West. Outside of those of theBahamas and Bermuda, they are the northernmost reefsfound within the western Atlantic. The Florida Keys areprobably home to more marine fish species than anyother coastal region of the mainland United States.59

Reefs here are a major tourism draw—over one milliondivers visit this area each year. Commercial and recre-ational fisheries are an additional and important sourceof income for local communities. For example, the spinylobster catch generated $10 million in 1980 alone.60

Threats: The coral reefs of the Florida Keys exemplify thecomplexity of threats to reef resources. They naturally lienear the temperature limits for reef building. Strong win-ter cold fronts have episodically killed Acropora thicketsthroughout the Keys. Florida reefs have been repeatedlystressed in the past 25 years by bleaching events in 1973,1983, 1987, 1991, and 1997. Disease is an even moreserious problem: two of the most important reef-builderspecies (Acropora palmata and A. cervicornis) are now rela-tively uncommon due to white-band disease, while oth-ers have proved particularly susceptible to black-banddisease. New coral diseases are being reported eachsummer.

The two major threats to these reefs are pollutedwaters from Florida Bay and anthropogenic nutrientsfrom storm runoff, discharge from sewage-laden ground-waters, and from agricultural sources. Even distantsources are involved: waters from the heavily pollutedMississippi River periodically reach the Keys whileSaharan dust has been implicated as an origin of nutri-ents and possibly disease spores particularly during ElNiño years. Finally, direct human activity is damaging

reef resources here. Activities such as boating, fishing,and diving individually cause minimal damage, butbecause of sheer numbers of participants result in chronicstress. The all too frequent groundings of large vesselshave resulted in loss of significant percentages of indi-vidual reefs. Aside from boating activities and despiteyears of research, it is difficult to lay blame for damageon specific anthropogenic stresses. However, it is clearthat human activity compounds the natural regional vul-nerability of Florida’s reefs, thereby severely threateningthe future integrity of these ecosystems.

Reef name: REEFS OF BAHIA LAS MINASLocation: Caribbean Panama

Description: Bahia Las Minas forms part of one ofPanama’s most extensive stretches of coral reef andmangrove along the Caribbean coast. These ecosystemsprovide an important source of food fish for local com-munities.61

Threats: A major crude oil spill occurred in April 1986from a ruptured storage tank at a local refinery just eastof the Caribbean entrance to the Panama Canal. Oilslicks from the refinery landfill and from mangroves(whose soils retained oil from the original spill) are stillcommon there after 10 years. The spill affected a widerange of reef community species. The cover, size, anddiversity of live corals decreased greatly on oiled reefs(for example, total coral cover declined by 76 percent inwaters three meters deep). The species Acropora palmata,a major Caribbean reef-building coral, was practicallyeliminated. Sublethal but long-term consequences forcorals include decreased growth, reproduction, andrecruitment, which suggest little prospect for rapid recov-ery. The spill also damaged nearby sea grass and man-grove communities.62, 63, 64

TWELVE REEFS AT RISK

The following profiles, contributed by some of the experts who helped us with this

assessment, illustrate the types of threats faced by reefs around the world and what

is at stake should these ecosystems continue to be degraded.

Reef name: JAMAICA’S REEFSLocation: Jamaica, Caribbean

Description: The entire island is surrounded by reefs,although those of the north coast once contained themost coral cover and are the most diverse. Reefs are anintegral part of the Jamaican economy, supporting fish-ing, and tourism, the country’s most important industry.65

Threats: Virtually all reef communities here have beenaffected by human and natural causes. Overfishing inparticular, as well as pollution from sewage disposal,industry and agricultural runoff, siltation due to poorland use practices, and tourism-related activities, haveseriously degraded Jamaica’s reefs. Storm damage fromhurricanes, coral reef bleaching due to periodic high seawater temperatures, and, with the decline of sea urchinsand other algae grazers, the unchecked algal overgrowthof corals have compounded the problem. The reefs sur-rounding Montego Bay are perhaps the most seriouslydegraded, even though they are protected, in part, by amarine park. The original park, established in 1966, wastoo small and was completely unmanaged. Althoughreestablished and expanded in 1990, with a financialbase and staff that works closely with town authorities,

reefs in the park continue to be affected by poaching,pollution from the nearby city and airport, and runofffrom inland agricultural activity.

Reef name: HIKKADUWA REEFSLocation: The Hikkaduwa Marine Sanctuary and thesurrounding reef, located in southwestern Sri Lanka,Indian Ocean

Description: Hikkaduwa is one of the most denselydeveloped tourism sites in Sri Lanka and encompassesthe first national marine sanctuary, established in1979. Coastal tourism is a mainstay of the country’seconomy. With 80 percent of all tourism infrastructurein coastal areas, the industry generates about $200 mil-lion each year. The tourism economy of Hikkaduwa isalmost entirely dependent on the quality of the beachand coral reef along its five-kilometer beach front.Gross annual revenue from about 150 tourism estab-lishments is more than $30 million.Threats: The coastal environment is increasinglydegraded from development’s impacts. Poor environ-mental planning, inadequate law enforcement, andlack of consideration of sociocultural issues are the


MAP 5.

primary underlying causes. Longtime residents of thearea have stated that “entire sections” of the reef havebeen destroyed over the last 20 years. The most impor-tant threat to the area is the unregulated operations ofa large number of glass-bottomed boats. These vesselshit the corals, anchors are dropped, and tourists standand walk on the reefs. Anchoring and dumping of oilby fishing boats is also a problem. Additional threatsinclude polluted water from fish holds and waste oildumped directly in the sanctuary, and sediments stirredup by boat traffic. Coral reef mining occurs within akilometer of this protected area, and many of the near-by reefs are devastated. The government and local com-munity are finally taking steps to limit boating activity,to require hotels to stop dumping wastewater into theocean, and to patrol the reef in order to prevent tram-pling of corals and illegal fishing.66, 67, 68

Reef name: RED SEA RIVIERA Location: Coral reefs in the Gulf of Aqaba off Jordan,Israel, and Egypt plus the reefs of the Egyptian Red Sea

Description: The coral reefs along the Red Sea Riviera arehigh-value resources for attracting European (primarilyGerman and Italian) tourists seeking diving adventures.They provide habitat for many commercially importantfish that are consumed in local hotels and restaurants.The extensive fringing reefs also help consolidate desertshorelines and protect them (and coastal property)from storms.Threats: The Red Sea Riviera is a good example of anarea that presently is only partially threatened, butwhere the potential exists for large-scale degradation.Overfishing and physical damage from excessive divingthreaten reefs in an area overlapping Jordan and

Israel—a region where tourism is expected to quadru-ple by the year 2000.69 In Egypt, where the number ofhotel beds (a measure of tourism demand) is expectedto increase over 1000 percent by the year 2005, theEnvironmental Affairs Agency (EAA) has been able tomanage the resort development process along thesouth Sinai with a measurable degree of effectivenessvia a network of coastal protectorates. However, offHurghada, tourism development proceeded without anactive management system in place and degradation(coastal sedimentation, physical damage from anchor-ing and overdiving, and overfishing) is clearly evi-dent.70, 71 In 1997, more than 250 mooring buoys wereinstalled off Hurghada and EAA assigned rangers topatrol the Elba Protectorate. EAA is working to expandits system of marine protected areas to include reefslocated north of Hurghada and stretching to the Sudanborder. The Tourist Development Agency is attemptingto better design new tourist villages to ensure the sus-tainable use of valuable coral reef resources. Time willtell whether Red Sea Riviera governments will take thenecessary actions to preserve their coral reefs in the faceof economic needs and rapid development.

Reef name: REEFS OF THE SOUTHERN ISLANDS(SINGAPORE)Location: Singapore

Description: Most of Singapore’s reefs lie off the SouthernIslands. This area is home to at least 197 species of hardcorals.72 The area supports a growing tourism industry, aswell as some subsistence and sport fishing.73

Threats: The Southern Islands reefs lie within the portlimits of the world’s busiest harbor, while the islandsthemselves support oil refineries, petrochemical indus-

tries, and slop-treatment plants. Thirtyyears of massive land reclamation pro-grams compounded with regular dredg-ing of shipping channels, has resultedin the widespread sedimentation ofcoral communities, posing the biggestthreat to this area. Underwater visibilityhas been reduced from 12 meters in the1960s to two meters today. The activegrowth zone of corals is now confinedto the upper five meters of reef slopes.The news is not all bad: thanks to care-ful sewage and industrial treatmentpractices, these coral communities stillsurvive despite their proximity to one of the most densely populated placeson earth.

Trampling of reefs by tourists is a threat at this Red Sea resort.

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Reef name: THE BOLINAO REEF COMPLEXLocation: Fringing reefs on western LuzonIsland in the Philippines

Description: The 200-square-kilometercomplex includes reefs from the munici-palities of Anda and Bolinao. Of approxi-mately 50,000 people in Bolinao, only afew thousand actually fish the reefs, butthe reefs support about 20,000 peoplewho are either workers in fishery-relatedoccupations (fish sales, shell craft, etc.) orare dependent family members.Threats: As farmlands across thePhilippines have become finely dividedand overutilized, increasing numbers of people havemigrated into reef areas such as Bolinao to join in har-vesting fish and other reef resources, contributing totheir dramatic decline. Competition for these resourcesled to the proliferation of blast and cyanide fishing. Inthe late 1980s one could hear an average of 10 blastsper hour from fishers targeting schools of fish andclumps of coral. The bottom cover of reef-buildingcoral diminished from roughly 40 percent to about 15percent over a period of about 15 years. Target fishwere 10 centimeters in length and less. While fishers ofmore pristine reefs in Papua New Guinea are able toharvest up to 30 kilograms of fish per day, the Bolinaofishers have had their catches reduced to an average ofabout one kilogram per day on reefs that were onceecologically very similar.

Beginning in 1986, programs were established bythe University of the Philippines and collaborators tohelp the Bolinao municipality. Various projects tointroduce small-scale mariculture of seaweed and inver-tebrates were supplemented by community organizingactivities. Public education and improved law enforce-ment have led to a reduction in blast fishing. Coralcover and fish abundances seem to be increasing. In1997, the municipality approved an integrated coastalmanagement plan that reflected the concerns of allmajor sectors. Marine protected areas are being estab-lished and fishery regulations are being revised.However, the reef remains in a critical state. The prolif-eration of fish pens is causing problems with pollution,water stagnation, and public access to reef resources.Incomes in the area remain low, and many resourceson land and sea are seriously overutilized by the densehuman population. Ultimately, the greatest challengesmay be yet to come—the population of Bolinao isexpected to double in the next 30 years.

Reef name: SCARBOROUGH REEFLocation: A large atoll in the eastern South China Sea

Description: Scarborough Reef is noted for high levelsof biodiversity. The populations of organisms on thereefs of the South China Sea are believed to be linkedthrough the exchange of the free-swimming life stagesthat characterize most reef species. Being highly isolat-ed, Scarborough Reef may play a particularly crucialrole as an “outpost” in this exchange of genetic materi-al and in the restocking of overfished fringing reefs inthe Philippines and China. Threats: Like the Spratly Islands to the southwest,Scarborough Reef is the subject of ownership disputes.The reef is claimed by the Philippines, mainlandChina, and Taiwan. Fishers from all three areas regu-larly fish the reef. However, the unclear ownership andlack of regulation exacerbate competition for theresources. Fishers stock up on blasting devices andcyanide to fish the reef in short, destructive trips. Thereef is a major site for shark fishing with gill nets andfor the capture of large fish for the live fish trade usingcyanide. Ships load their holds with coral to sell as dec-orations for store windows and aquariums.

The U.S. military used the reef for bombing practiceduring the 1990 confrontation with Iraq, complicatingmatters. Large and unique underwater dunelike struc-tures of organ-pipe coral tens of meters long were usedas targets. Substantial areas of coral were torn apart bythe explosions. Many of the bombs failed to explode,littering the lagoon with live ordinance. It is reportedlycommon for a fisher to drop a small explosive chargein a beer bottle, only to set off a massive explosion.Visitors to the reef over the years have reported increas-ing levels of degradation from the combination ofabuses to the reef.


Coral has encrusted this World War II bomb at Scarborough Reef.

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Reef name: SERIBU ISLANDS REEFSLocation: Java Sea, north of Jakarta, Indonesia

Description: The Seribu Islands reefs cover 108,000hectares, along a chain of more than 100 small islands.The area is noted for its abundance of attractive beachesand coral reefs. In 1995, the islands were declared amarine national park. Tourism has grown rapidly fromone operator on a single island in 1982 to 11 operatorsworking out of 18 islands in 1992. There were approxi-mately 8,000 visitors in 1991. Some islands have longbeen inhabited by villagers who depend on reef andisland resources. However, the tourism industry employsless than 5 percent of the local population.Threats: Domestic sewage, industrial effluent, and urbanrunoff from Jakarta threaten the southernmost portionof this area. Floating garbage is a problem, dependingon prevailing winds. Ballast water discharges from boatsresult in tar being washed up on local beaches. Blastfishing, although outlawed nationally since 1920, stilloccurs as well as heavy ornamental fish collecting andmajor subsistence exploitation of marine resources. Theislands are under pressure from developers seeking moretourism and recreational facilities to service greaterJakarta. There is no strategy to promote environmentallyand economically sound expansion of this industry. Boatanchoring and diving have already damaged coral reefs.To encourage protection of the area, local residents, fewof whom currently benefit from existing recreationaldevelopment, need more economic options andincreased participation in park activities (such asemployment servicing the resorts). Oil and gas explo-ration, taking place within kilometers of the park, couldpose a potential future threat.

Reef name: JOHNSTON ATOLL Location: Line Islands, Central Pacific, anisland possession of the United States

Description: Johnston is a small ancientatoll (80 million years old) and is per-haps the most isolated reef in the world,being 800 kilometers southwest ofHawaii, its nearest island neighbor, and1,500 kilometers north and east of theNorthern Line Islands and the PhoenixIslands, respectively. These reefs areimportant for biodiversity, serving as abiological stepping stone betweenHawaii and the island groups to thesouth and west. The 30 species of coralhave close affinities to the coral biota ofHawaii, and corals, reef fishes, seabirds,

and green turtles flourish on the reefs and islands of theatoll. The atoll is a national wildlife refuge, jointlyadministered by the U.S. Fish and Wildlife Service andthe U.S. Department of Defense.Threats: Beginning about 1960, the United States estab-lished Johnston as an above-ground atmosphericnuclear and missile testing range. Massive dredging andfilling destroyed many reefs in a process to expand thesize of main islands and to build an airport, deep draftport, and entrance channel. Some Thor missile launchesfailed, with one scattering plutonium on the island andnearby reef. Later thousands of drums of Agent Orange,a defoliant used during the Vietnam War, were shippedto Johnston where they were stockpiled for years out inthe open. Eventually a floating incinerator shipdestroyed the defoliant, but not before many of thedrums leaked, discharging dioxins and other toxic sub-stances into the groundwater. In 1970, explosively con-figured chemical munitions, including blister agent andnerve gases, were removed from Okinawa and stock-piled at Johnston. Rapid deterioration of the munitionsprompted the U.S. Army in the mid-1980s to constructa high-technology incinerator to destroy them. Theplant is still incinerating the munitions today, subject tovarious safeguards of the U.S. government.

Reef name: CHUUK LAGOON (TRUK LAGOON)Location: Central Caroline Islands, western Pacific,Federated States of Micronesia

Description: Chuuk Lagoon is the largest single barrierreef in Micronesia, enclosing reefs and a lagoon with26 volcanic islands and 22 low coral islets. It is also thelargest urban center and the capital of Chuuk State in


Achilles Tangs are one of the many reef fish species found on Johnston Atoll in the Pacific.

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Micronesia, home to nearly 50,000 residents livingmostly on several of the larger volcanic islands. Theatoll is noted for an exceptional diversity of fish,marine invertebrates, and coral species (about 300species of stony corals were recently cataloged here).Chuuk is also a significant cultural center having beencontinually occupied by Micronesians over the pastseveral thousand years. During World War II, nearly 70Japanese naval vessels were sunk during a 1944 battle,Operation Hailstone. During the past half century thewrecks have been colonized by fish, sponges, seaweeds,and soft corals. The shipwrecks of the lagoon are nowone of the premier sport diving destinations in theworld due to luxuriant reef growth and the historic sig-nificance of the wrecks. Several dive operations andmost of the subsistence fishermen rely on the reefs andlagoon for their catch. Threats: Japanese military construction and OperationHailstone were the first major insults to Chuuk’s coralreefs. After the war the human population expandedrapidly, placing ever increasing demands on marinefood resources (reef fish and shellfish). Fishers haveremoved explosives from the residual World War IImunitions on the atoll, making them into bombs andusing them to blast reefs to stun, kill, and collect fish.Blast fishing is still a serious threat to reefs, especially inthe more remote western lagoon, beyond the watchfuleyes of villagers and government enforcement. Blastinghas damaged about 10 percent of the reefs in the lagoonaccording to a 1994 survey. Heavy urbanization, espe-cially on Tonowas and Weno, has spurred dredging andfilling for land expansion and development, while

sewage discharges into the lagoon from the islands hasreduced water quality and subsequently underwater visi-bility at many of the dive sites. Reef fish populations arebeing depleted from heavy fishing pressure, and nestingsea turtle populations have nearly been eliminated fromthe area. Rubbish is haphazardly dumped into man-grove areas on the most populated islands, furtherdegrading water quality.

Reef name: REEFS OF THE WINDWARDSOUTHEASTERN HAWAIIAN ISLANDSLocation: Main Hawaiian Islands (USA), tropical Pacific

Description: The eight volcanic islands are generallylarge (100 to 16,000 square kilometers), with the foursmallest (Lanai, Molokai, Niihau, and Kahoolawe)sparsely settled and the largest (Oahu, Maui, Hawaii,and Kauai) supporting rapidly growing urban popula-tions. The Hawaiian Islands reefs are not noted forhigh levels of coral, fish, and other reef species.However, about 25 percent of their fauna consists ofendemic (unique) species, a manifestation of near con-tinuous geographic isolation over a long time period.Threats: During the past century, plantation agricul-ture, ranching, and feral livestock introduced to theislands reduced natural ground cover, increased soilerosion, and subjected reefs to heavy sedimentationespecially off Oahu, south Molokai, northeastHawaii, east Kauai, and Maui. Military, and morerecently tourism development since World War II hasled to dredging and filling of many reefs, and coastalsedimentation and heavy use of some reef sites.

However, the most serious threatsrelate to rapid population growthand urbanization, leading tosewage discharges, additionalconstruction, overuse, overfish-ing, industrial discharges, andport development and opera-tions. A spate of governmentenvironmental laws and regula-tions and coastal planning nowcontrols many but not all ofthese influences, and overfishingand water quality degradationfrom nonpoint sources andsewage will continue to be seri-ous if not growing threats to thereefs. Reefs within embayments,such as Kaneohe (off Oahu), areparticularly vulnerable to urban-related development.


Military debris have become substrate for coral at Chuuk Lagoon.

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These data gaps are not for lack of tools. There area range of techniques for assessing and monitoringcoral reefs, each with advantages and limitations.Generally, these entail tradeoffs between cost anddetail, and range from the use of satellite imagery tomap reef location (relatively low cost, but low detail)to running underwater transects to measure reefhealth (high cost, high detail). The optimal approachis through multilevel sampling, where informationobtained from limited, detailed high-resolution sampling is extrapolated to large areas based on low-resolution data of wide coverage. The goal is touse as much information as possible and available to improve assessments at national, regional, andglobal scales. The box titled “Tools and Techniquesfor Monitoring and Mapping Coral Reefs” describessome of the technological options at hand for assessing reefs.

As of 1998, several major new initiatives wereunderway to collect new data and synthesize existinginformation so as to build a picture of the status ofreefs worldwide. These include:

Global Coral Reef Monitoring Network (GCRMN):GCRMN will rely on governments and local communi-ties to regularly assess the health of coral reefs andtheir fish populations in about 80 countries of theworld. Permanent transects are to be established onmany reefs. The data will be fed into ReefBase (seebelow). GCRMN is coordinated by the AustralianInstitute for Marine Sciences and the InternationalCenter for Living Aquatic Resources Management andis a joint program of the International OceanographicCommission, the World Conservation Union (IUCN),and the United Nations Environment Programme.

Reef Check Program: Through this volunteer effort,hundreds of diving groups around the world are orga-nizing annual field trips to gather transect data onselected coral reefs. The Reef Check protocol (method-ology) is simple, requiring only a few hours to explain,but is dependent on the involvement of coral reef sci-entists to supervise site selection and data gathering.Three hundred reefs in 30 countries were surveyedbetween June and August 1997.


IMPROVING OURKNOWLEDGE BASE

The Reefs at Risk indicator presents our best estimate of likely threats to coral reefs

from human activities, but it is only an estimate. Our results confirm that there is

a critical need for detailed monitoring and assessment of reef habitats in order to

better document where and how coral reefs are threatened and to understand what measures

are needed to safeguard them. Scientists and managers have only rudimentary, incomplete

data on the status and health of coral reef ecosystems. For example, we still lack a complete

global map depicting reef location, and the vast majority of coral reefs are unassessed. This

and other basic information is essential for informed decision making by resource manage-

ment agencies, fishers, the tourism industry, and other sectors economically dependent on

reef resources. The public, non-governmental organizations and scientists need such data to

better understand and advocate for the protection and stewardship of coral reefs.

ReefBase AquanautMethod: The ReefBaseAquanaut Method hasbeen developed toempower divers to con-duct highly reliable sur-veys independent of sci-entists. Professional scubainstructors teach the four-day training course as anadvanced specialty course.In addition to volunteers,park rangers and mem-bers of governmental andprivate sector groupstasked with coral reefmanagement also use thetraining. In the ReefCheck and Aquanaut sys-tems, data exchange anddissemination are facili-tated through ReefBase(see below).

Other volunteer programs: Throughout the world,increasing numbers of volunteers are conducting coralreef surveys with organizations such as Reef Watch,Reef Keeper, REEF, Frontier, and Coral CayConservation. Efforts are underway to coordinate thiswork. In many cases, volunteer surveys have had sub-stantial impact on coral reef management and publicawareness.

ReefBase: ReefBase was initiated in late 1993 to con-solidate and disseminate information useful in manag-ing coral reefs.74 This database, produced by ICLARM, isthe most comprehensive source of information on reefsavailable, providing ecological and socioeconomic dataon sites around the world. It includes digital maps ofcoral reefs provided by the World ConservationMonitoring Centre (WCMC), space shuttle and satelliteimages contributed by the National Atmospheric andSpace Administration (NASA) and others, and pho-tographs of reefs contributed by volunteers. ReefBase is currently distributed yearly on CD-ROMs, and major portions are available through a Web site(www.reefbase.org).

Bringing scientists together: The InternationalCoral Reef Symposia (ICRS) are held approximatelyevery four years, and serve as a primary focal point forthe analysis and official release of information on coral

reef status (the next session will be held in 2000 inBali, Indonesia). In November 1998, a new series ofconferences will be initiated, focused particularly onmanagement concerns. The first International TropicalMarine Ecosystem Management Symposium, to be heldin Australia, will provide a forum for the evaluation ofthe success of the International Coral Reef Initiative inthe three and a half years since the first global work-shop. Other periodic conferences of importance in therelease and critical evaluation of reef informationinclude the regional meetings of the InternationalSociety for Reef Studies, the Pacific Science Congresses,the West-Pac Conferences, and many others.

Most available data collection is focused on the bio-logical and physical dimensions of reefs: species foundwithin these ecosystems, the location of these habitats,degree of degradation, etc. Socioeconomic and politi-cal information can help managers, scientists, andothers better understand the direct and underlying fac-tors that result in changes in reef condition (for exam-ple, subsidies and laws that result in overfishing).Information that can be used to quantify the directand indirect values derived from coral reef ecosystemsis important input for weighing development andmanagement options. Collection of such policy-relevant data should be a priority in future monitoringand assessment efforts.


Reef surveys by scientific teams and by recreational divers in volunteer programs are improving ourknowledge of the condition of coral reefs around the world.

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Satellite-based sensors: Satellite imagery can be usedfor low-cost, albeit coarse-scale mapping of coralreefs, and as such is probably the most effective wayto build a comprehensive picture of where theworld’s reefs are located. Satellite data can also pro-vide information on sea-surface temperatures, waveheight and direction, and primary production inupper waters. They may also be useful for distin-guishing living from dead coral in very shallowwaters. Military agencies have more comprehensivesatellite data, often at a much finer resolution; how-ever, these data are rarely available for public use.75, 76

Aerial photography and sensors: Photos and datafrom overflights of reefs can provide a more detailedpicture of reef location, and can yield bathymetricdata to depths of several tens of meters.77 However,aerial surveys and the analysis of their products arefar more costly than those derived from satelliteinformation and are difficult or impossible to con-duct legally in many countries because of securityconcerns. These data can determine living from deadcoral, but only within very shallow water.78 Costs havebeen reduced by using ultralight aircraft,79 balloons,kites,80 and other devices. With improvements in com-puter technology, it will be possible to survey reefswith remote-controlled aircraft, further cutting costs.81, 82, 83, 84

Ship and boat-based sensors: Research vessels carry arange of sensors useful for detailed mapping of coralreefs. Various types of sonar can be used to producethree-dimensional images of coral and distinguishbetween different types of bottom substrate. Passiveacoustic analysis, along with sonar in someinstances, can distinguish between live and deadreefs. Research vessels play a vital role in surveyingand mapping coral reef habitats. However, they arecostly to operate (generally ranging around $10,000per day). One way to reduce costs, and better utilizeexisting research vessel fleets, is to conduct reef sur-veys during the course of other oceanographic andfishery investigations.85, 86

Submersibles: Manned and unmanned submarinesplay an essential role in assessing coral reefs inwaters below a 30-meter depth—beyond the practi-cal working limits for scuba diving. Although thetechnological capacity available for exploring theworld’s oceans is highly developed, there are very fewsubmersibles in the world that are available forundersea research. Promising new technologies arecoming on line for conducting transect surveys, dis-tinguishing live from dead coral cover using laser-line sensing devices, and conducting rapid, large areaassessments at various depths including shallowerwaters accessible by scuba divers.87, 88

Diving surveys: Scuba-diving scientists are the mainsource of information on reefs in shallower waterstoday (down to 30 meters in depth). However, thespecific objectives, taxa of focus, and samplingapproaches severely limit the comparability of thedata among regions and over time. In addition,scuba-based assessments and monitoring are limitedby the number of scientists available for this workand the small area that can be covered by one indi-vidual. Survey protocols are being developed so thatrecreational divers and others can help gather data,often on a volunteer basis. This offers tremendouspotential for gathering new information on reefs,since there are several million scuba divers in theworld and several times as many people proficientat skin diving with mask or goggles. Similarly, resi-dents of coastal communities can be recruited toevaluate their reefs through participatory resourcemapping. This low-tech approach is particularly rel-evant in developing countries, where few can affordexpensive scuba equipment. Here, villagers aretrained to gather general information on the cover-age of various ecosystems, supplemented withdescriptions of simple factors such as hard coralcover, and then transfer the data to a map using asimple compass. Work on this type of approach isunderway through various programs, such as theCoastal Resource Management Program in thePhilippines.89

Tools and Techniques for Monitoringand Mapping Coral Reefs

This report, because it is an indicator analysis, doesnot list policy recommendations, or provide a compre-hensive overview of management approaches and initia-tives to protect and conserve reef ecosystems. Instead,we provide a few examples of the types of efforts underway to address threats to these habitats.

The box “International Agreements and Initiatives”outlines some of the global activities that are helpingto focus attention on coral reefs and, in some cases, tomobilize governments and people to better monitorand manage these habitats. The section titled“Improving Our Knowledge Base” details some of the

data collection efforts under way worldwide to trackthe health of reef ecosystems.

The most important actions for promoting healthycoral reef ecosystems are taken at local and nationallevels. These depend on efforts by local governments,community groups, environmental organizations, theprivate sector, and others. Successful approaches areoften based on cross-sectoral planning and manage-ment at a landscape scale to assure, for example, thatagricultural policies within inland watersheds do notimpact reef-dependent fisheries and tourism along thecoast. Some of the actions that can best protect reefs


PROTECTING THEHEALTH OF CORALREEF ECOSYSTEMS

Maintaining the biological diversity, condition, resources, and values of coral reefs and relatedecosystems is a matter of global urgency. While the majority of countries which have coral reefs aredeveloping countries, there are many reefs in the waters of developed countries. This unites thedeveloped and developing countries and should command the attention of the international community.Coral reef survival depends upon the world community acquiring and maintaining the knowledge andcapacity to conserve and sustainably use coral reefs and related ecosystems. This requires that all usesand impact be brought within and maintained at levels which do not exceed these systems’ naturalcapacity for production and regeneration.

—from the International Coral Reef Initiative Framework for Action

Reefs at Risk demonstrates that coral reefs around the world face threats from over-

fishing, coastal development, and other human activity. In most places these pres-

sures will grow as economies develop and coastal populations swell. Despite these

sobering trends, the news is not all bad. Careful planning and management can assure

healthy reefs while meeting the needs of local people. Increased concern about, and interest

in, coral reef issues is translating into action at local, national, and international levels to

protect and conserve reef resources. As we illustrate at the end of this section, promising

efforts are under way in many parts of the world.

are not directly linked to conservation. They rangefrom building sewage and industrial waste treatmentfacilities to minimize pollution of coastal habitats toremoving the host of subsidies and incentives—in theagricultural, forestry, development, fisheries, and othereconomic sectors—that result in degradation of waterquality, direct destruction of reef habitats, and overex-ploitation of reef species.

For these approaches to work, legislation backed upby enforcement of these laws and regulations must bein place to protect reef resources. Restrictions alone willnot work. Successful management approaches addressthe underlying causes of reef degradation by promotingeconomic development while protecting coral reefhabitats. Examples include providing alternative liveli-hoods for people engaged in destructive activitiesthrough economic necessity, training fishers to use lessdestructive fishing methods, and regulating access anduse of reef resources by establishing community owner-ship over reef fisheries and through other approaches.Environmental education plays an important role inbuilding public support for better reef management.

One of the most effective approaches for combatingthreats to reefs is through a well-managed, representa-tive marine protected area system (see box “Reefs andMarine Protected Areas”). Marine parks, sanctuaries, andreserves can protect reef ecosystems and species whilegenerating tourism dollars and maintaining the vitalityof nearby fisheries. The World Conservation Union hascalled on countries to protect 10 percent of all habitattypes. However, with one or two exceptions (such asAustralia), countries protect a far lower percentage oftheir coral reefs, and all have a long way to go in orderto meet a recently proposed global target of protecting20 percent of the oceans. Protection alone, however,cannot safeguard reefs from the sedimentation, pollu-tion, and other threats that originate outside theboundaries of parks and reserves.

Around the world, governments and people are takingsteps to conserve and restore coral reef ecosystems. Sevenexamples, most contributed by experts who helped uswith the Reefs at Risk assessment, are profiled below.

Reef: BERMUDA’S CORAL REEFSLocation: Bermuda, Atlantic OceanSigns of progress: Catch levels of grouper and snapper,two important reef species, declined significantly fromthe mid-1970s, apparently due to overharvesting. Totalgrouper catch per fishing pot (a fish trap commonlyused to catch reef species) dropped from 1.8 to 0.65kilos between 1975 and 1985, with smaller fish increas-ingly predominating. Meanwhile, fish traps and boat

anchoring by fishers and recreational boats were dam-aging reef structure.90 Under pressure from hotel owners,dive operators, and other businesses, the governmentclosed the $2 million pot fishing industry in 1990,compensating fishers for the cost of their gear and lostrevenue. In doing so, Bermuda recognized the impor-tance of its lucrative reef-based tourism and recreationalindustries—valued at over $9 million in 1988—whilebenefiting reef biodiversity in the process.91, 92

Reef: TUBBATAHA REEF Location: Sulu Sea, PhilippinesSigns of progress: In the late 1980s, overfishing anddestructive fishing practices were rampant here, withcoral cover reduced by 50 percent over a five-year periodending in 1989.93 The 33,200-hectare area is now anational marine park (the only one in the Philippines)and was declared a UNESCO World Heritage Site in1994. Non-governmental organizations and the govern-ment have worked together to manage the park since itsestablishment in 1988. The navy, with assistance fromNGOs, is patrolling the area to stop illegal fishing. In1997, all fishing activities were halted within the parkand a ranger station was constructed. In 1998, a parkmanagement board was put into place. Environmentaleducation materials have been disseminated to stake-holders in the area, and the dive tourism industry ishelping to install anchor buoys and regulate the activi-ties of divers on the reefs. The condition of the coralreef substrate has improved remarkably since 1989 andthe diversity of fish is exceptionally high.94

Reef: APO AND BALICASAG ISLAND REEFSLocation: Central Visayas, PhilippinesSigns of progress: In the late 1970s, blast and cyanidefishing, as well as other destructive fishing practices,threatened these and other reefs in Central Visayas.Thanks to a community-based marine managementprogram, put in place in the mid-1980s, these practicesceased by 1997. Under this program, SillimanUniversity staff helped organize local people intomarine management committees. These groups thenset up marine reserves that included no-fishing sanctu-aries on one portion of the reef. With the aid of munic-ipal governments, residents have continued to preventreef damage from fishermen and divers, both withinand outside the sanctuaries. A growing tourism indus-try catering to scuba divers is providing much neededrevenue to local communities. In 1992, surveys indi-cated that live coral cover and fish populations withinthe sanctuaries had increased substantially along withfish yields per unit area off Apo Island.


Reef: KOMODO NATIONAL PARKREEFSLocation: Off the coast of Flores,eastern Indonesia Signs of progress: The park (which isalso a Man and Biosphere Reserveand a World Heritage Site) covers1,320 square kilometers of waterand adjacent land areas. Reefs hereexhibit exceptionally high fishspecies diversity (home to an esti-mated 900 to 1,000 fish species).The area is also home to manytypes of corals, sponges, and marinemammals. Fishing and tourism aremajor income generators in the areaaround the park. However, theseresources have been under seriousthreat due to destructive fishingpractices.

To combat overfishing and destructive fishing prac-tices, The Nature Conservancy and the KomodoNational Park Authority developed a marine resourcemanagement plan, which is now in the early phase ofimplementation. Along with beefing up law enforce-ment, they are working with local communities topromote alternative livelihood programs, and haveinitiated training and awareness-building and otherprojects. These activities are paying off. For example,dynamite fishing went down from an average of morethan 10 blasts per month in early 1996 to around oneblast per month in late 1996 when routine park patrolswere started. Fishermen are being encouraged, success-fully, to shift their efforts to catching deeper-waterspecies, keeping them off the reefs.

Reef: PALAU ROCK ISLANDSLocation: Palau (southern lagoon of main islands),western PacificSigns of progress: The 500 rock islands located in thesouthern lagoon are renowned for their beauty. Thelagoon supports the largest hawksbill sea turtle popula-tions in Micronesia, although nesting adults are beingseriously overharvested. Palau also boasts exceptionalspecies diversity of reef life and supports other marinemammals and reptiles, such as dugongs and saltwatercrocodiles, not found elsewhere in Micronesia. Urbanand resort development pose the most serious threatsto this area. The Nature Conservancy and the PalauConservation Society are successfully working withlocal communities and the government to protect thePalau reefs.

Reef: MOMBASA MARINE NATIONAL PARKLocation: KenyaSigns of progress: The Mombasa Marine National Parkis adjacent to the most heavily populated tourist beachalong the Kenyan coast. The reefs are threatened byoverfishing, destructive fishing from beat seining andspear fishing, organic pollution and sedimentation,and tourist damage from trampling. The reduction ofpredatory fish led to increases in burrowing seaurchins, whose excavations began to reduce the reefframework to rubble. In 1989, the area was officiallygazetted by the Kenya government as a marine park.Management activities include patrolling, beach clean-ing, regulation of tourist activities (including glass bot-tom boat excursions), and maintenance of moorings.Surveys carried out since 1988 have shown a majorincrease in fin fish size, abundance, and diversity;recorded coral cover has increased from 8 to 30 per-cent; and sea urchin numbers have decreased steadilythroughout the survey period. The number of sea tur-tles recorded nesting in the area has also increased.

Reef: GREAT BARRIER REEF WORLD HERITAGEAREA AND MARINE PARKLocation: AustraliaSigns of progress: The Great Barrier Reef actually consistsof about 3,000 individual reefs spread over at least350,000 square kilometers. The largest reef in the world,it still remains in generally good condition, althoughrunoff of silt, nutrients, and contaminants from agricul-tural, urban, and industrial areas may pose localizedthreats in some places. The marine park embraces the


The coral reefs of Palau support exceptional species diversity.

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The development of a global system of marine protected areas(MPAs) lags far behind that of the terrestrial biosphere in boththe extent and the effectiveness of its coverage. Nonetheless,it is increasingly apparent that MPAs can play a vitally impor-tant role in protecting marine habitats, particularly when form-ing part of a wider program of measures for coastal andmarine management. Many coral reef scientists and managerspromote the inclusion of small reserves in planning at the scaleof the municipality, while large reserves are the necessary sup-plement to ensure sustainability and to provide for the needsof species requiring large areas to forage.

Based on what is probably the most comprehensive list cur-rently available,* we estimate that there are at least 400 MPAsincluding coral reefs in more than 65 countries and territories.(See Map 6.) Although important as it currently stands, this listclearly does not represent anything like a global network,although it does provide a framework for one. There are at least40 countries with no formal protection for their coral reefs, andthere are significant regional gaps in this network. The IndianOcean region, the west coast of the Americas, SolomonIslands, Fiji, French Polynesia, and the Philippines, for example,are all underrepresented. With the exception of a few verylarge sites such as the Great Barrier Reef, the Florida KeysNational Marine Sanctuary, and the Ras Mohammed ParkComplex in Egypt, the great majority of protected coral reefsare very small indeed: more than 150 of the MPAs mentionedare less than one square kilometer in size. Outside of thelargest sites just mentioned, it is likely that less than 3 percentof the world’s coral reefs are protected.

MPAs provide some of the great points of hope for coralreefs. The Great Barrier Reef, the world’s second-largest pro-tected area (after northeast Greenland!), is a model of inte-grated and multiple-use management, allowing sustainable uti-lization of the reef by a wide range of users with numerous andoften conflicting needs. Bonaire Marine Park in the Caribbean isone of the first self-funding protected areas, supported entirelyfrom tourist revenues (which also bring in half of that country’stotal gross domestic product). Apo Island, in the Philippines, is a

tiny fishing reserve that, in the years since its designation, hasallowed stocks to recover sufficiently so that local fishermenoperating in the surrounding areas are reporting major increas-es in fish yields. Such cases provide overwhelming support forthe economic, social, and political arguments to protect coralreefs.

However, many existing MPAs exist only as “paper parks”where legislation is not enforced, resources are lacking forprotecting these areas, or management plans are poorly con-ceived. In other MPAs, management safeguards are in place,but pressures outside parks and reserves undermine theintegrity of protected marine habitats. This was documented ina recent global study, where of 383 MPAs assessed for man-agement effectiveness, conservation objectives wereachieved at less than a third (117) of these sites (that is, man-agement effectiveness was ranked as “high”).95

Johnston Atoll serves as one example of this problem (seesection titled “Twelve Reefs at Risk”). Probably among the earli-est designations of a coral reef protected area, this site hasbeen subjected to massive military development, high atmos-pheric nuclear testing, chemical waste disposal, and otherthreats. Elsewhere, external influences beyond the control ofthe management agencies undermine protected marine habi-tats. Reefs are highly dynamic and open systems. They cannotbe fenced off and are dependent on the flow of currents carry-ing nutrients, circulating water and oxygen, and transportinglarvae and other materials. But it is these same water move-ments that carry pollutants and sediments into protected areas,while overfishing upstream of a reef may cut off the vital supplyof new recruits of coral and fish to the reef community.

In this assessment, we found that reefs within many MPAsare under high potential threat. These include the Gulf ofMannar National Park in India; Bunaken, Bali Barat, Komodo,and Kepulauan Togian National Parks in Indonesia; MochimaNational Park in Venezuela; Iriomote and Okinawa KaiganNational Parks in Japan; Pulau Tiga and Turtle Islands inMalaysia; Corals del Rosario in Colombia; and others.Protected areas can play a vital role, and act as flagships forthe protection of coral reefs, but cannot be designated in isola-tion. The need for a more concerted and broadly based man-agement regime, in many cases crossing national boundaries,will be essential for the ultimate protection of many reefs.

Reefs and Marine Protected Areas

*Taken from the World Conservation Monitoring Centre’s Protected AreasDatabase, a global database managed in collaboration with the IUCN’sWorld Commission on Protected Areas, which houses information on morethan 30,000 sites, including more than 3,000 marine protected areas.

total reef area. Mining is banned, but most of the area isopen to fishing and diving and, in some locations, tothe development of tourism infrastructure. About 20percent of the reef is zoned as “no take” areas, where

fishing is off-limits. Commercial prawn trawling is taking its toll, however, on sea floor structure and bio-diversity. These effects, and those of line fishing, aresubject to scientific assessment through large-scale


investigations. Strong stakeholderinvolvement, education programs, andenforcement are all combined to achievecompliance with, and support for, parkregulations and management plans. TheGreat Barrier Reef World Heritage Area isa classic and often cited example of howmanagement can be applied successfullyto conserve entire ecosystems.

The International Coral ReefInitiative’s Framework for Action (seebox “International Agreements andInitiatives”) outlines the broad types oflocal and national efforts needed toassure the integrity of reef ecosystems.These include, but are not limited to,involving stakeholder groups at all levels of decisionmaking; integrated coastal zone management; educat-ing the public, policy-makers, and others about reefissues and how these habitats should be managed;strong environmental laws; encouraging micro-enter-prise development; promoting environmentally soundland use practices; cracking down on illegal fishing and

promoting sustainable fisheries management; develop-ing disaster strategies to minimize threats to reefs whenoil spills and unforeseen events occur; and developingan effective network of marine protected areas. Ifimplemented, these steps would help ensure that reefsat risk today are maintained as healthy ecosystems inthe future.

Protection and proper management can allow damaged reefs to recover.

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MAP 6.


Although there are no internationally binding conservationtargets or treaties related specifically to coral reefs, a rangeof existing initiatives and agreements are in place that havehelped focus attention on these ecosystems. These include:

The International Coral Reef Initiative ((ICRI):This effort was first launched in 1995, under the sponsor-ship of eight countries (the United States, Philippines,Japan, Australia, Jamaica, France, Sweden, and the UnitedKingdom). ICRI seeks to promote the sustainable man-agement and use of coral reefs and related ecosystems(mangroves and sea grass beds) through a range of activi-ties that have included regional workshops to identifyarea-specific issues and priorities and opportunities forcollaboration between countries.

The Framework for Action: A major outcome of thefirst ICRI workshop was the production of a Framework forAction, which was subsequently agreed to by representativesof at least 80 governments and a variety of non-governmentalorganizations and funding agencies. This framework includesactions to be taken in the areas of management, capacitybuilding, research and monitoring, and review. For the frame-work to be effective, it must be strongly supported andaccepted as the standard guideline for the implementation ofimproved coral reef management.

The International Year of the Coral Reef: As part ofan international awareness-raising campaign under ICRI,1997 was declared the “Year of the Reef.” Environmentalorganizations, museums and aquaria, research institutions,and other groups hosted activities to promote public educa-tion, data collection and assessment, and reef managementaround the world.

The International Year of the Ocean: The UnitedNations declared 1998 the “Year of the Ocean” to help main-tain media and public attention on coral reefs and othermarine habitats.

Protected area targets: The World ConservationUnion (IUCN), a nonprofit organization with a broad gov-ernment and non-governmental organization membership,proposed, in 1992, that countries protect a minimum of 10percent of their ecosystems, a target that has since gainedwide endorsement.96 More recently, at an AmericanAssociation for the Advancement of Science special sympo-sium on marine protected areas held in Seattle in 1997, Dr.Jane Lubchenco called for the setting aside of 20 percent ofthe surface area of the world’s oceans as no-take protected

reserves by the year 2020. Within no-take areas, all fishingis prohibited. The 20-percent-by-2020 goal is supported bya number of scientists and other experts, who recommendthat it be a major focus of activities beyond the InternationalYear of the Reef.97

The Convention on Biological Diversity: This 1992binding agreement requires countries to develop and imple-ment strategies for the sustainable use and protection of bio-diversity, including that of marine ecosystems. Many of thesignatory nations have developed national-level strategiesand action plans to this end. Marine issues are specificallyaddressed in the convention’s 1995 Jakarta Mandate onCoastal and Marine Biodiversity.98 To date, however, few con-crete actions have been taken to implement this workplan.

Convention on International Trade in EndangeredSpecies of Wild Flora and Fauna (CITES): This bindingagreement, which came into force in 1975, prohibits mostinternational trade of certain species (Appendix I species)and regulates that of others through a permit system(Appendix II species). All stony corals and black corals arelisted as Appendix II species, and as such receive some pro-tection, although currently it is difficult to track their tradedue to nonstandardized reporting protocols.99 CITES couldbe a more effective treaty for protecting coral reef biodiver-sity if there were adequate data on the status of marinespecies (without proof that a species is threatened, thereare no grounds for limiting its trade).

There are a range of other international agreements andinitiatives covering marine pollution, land-based pollution,fisheries, and protected areas relevant to coral reefs. Theyoffer both mechanisms for reducing human impact on reefecosystems (for example, the United Nations Conference onthe Protection of the Marine Environment From Land-BasedActivities and the Convention for the Prevention of Pollutionfrom Ships) and means for better protecting coral reefs (forexample, World Heritage Convention, Ramsar Convention,and the UNESCO Man and Biosphere Programme).100

International Agreements andInitiatives

Implementation of the Reefs at Risk Indicator

Reefs at Risk is a global assessment of likely threats tocoral reefs from four separate threat factors: coastal devel-opment, marine-based pollution, overexploitation ofmarine resources, and inland pollution, including sedi-mentation. Zones of high, medium, and low threat wereestimated for each of the threat factors, and were com-bined (through spatial overlay analysis) with a data setreflecting the location of coral reefs. Coral reefs are repre-sented by a four-kilometer resolution data set (55,168cells) reflecting shallow coral reefs of the world from theWorld Conservation Monitoring Centre. This data set wasclassified as follows:

■ Reefs classified as under high threat in at least one ofthe individual threat factors were classified as underhigh threat overall;

■ Reefs classified as under medium threat in at leastone threat factor were classified as under mediumthreat overall; and

■ Reefs classified as under low threat in all four threatfactors were classified as under low threat overall.

Details of the individual threat factors follow.

Implementation of the Coastal Development ThreatFactor

Proxies were developed to reflect the likely threat frompollution and sedimentation associated with coastaldevelopment. Stressors within the threat factor are citieswith a population of more than 100,000, settlements ofany size, airports (including some military bases), mines,and tourist resorts. Both the rationale for inclusion ofeach of these stressors and the details of implementationare described below.

Cities: Cities were differentiated based both upon sizeand upon likely level of sewage treatment, as both areimportant factors relating to the potential threat a citypresents to nearby coral reefs. All cities with a populationof 100,000 or more were differentiated as to likely level ofsewage treatment based upon income level. Additionally,large cities (above one million and five million personthresholds) were assumed to have larger zones of poten-tial effect than smaller cities, regardless of income level.

Cities with populations of more than 100,000 comefrom the World Cities Data Base by Birbeck College.

The World Bank’s classification of income level wasused as a means of differentiating likely degree of treat-ment of sewage for all cities with a population of morethan 100,000. Cities in low-income and lower-middle-income countries were assumed to have little treatmentof sewage, while those in upper-middle and high-income countries were assumed to have at least moder-ate treatment.*

Areas were classified as being under high threat if with-in 10 kilometers of a city assumed to have little sewagetreatment. Areas were classified as being under mediumthreat if within 10 kilometers of a city assumed to have atleast moderate sewage treatment or within 25 kilometersof a city assumed to have little sewage treatment.

The additional threat associated with large cities wasimplemented for two population sizes. Areas were classi-fied as being under high threat if within 20 kilometers ofa city of one million or more, or within 30 kilometers ofa city of five million or more. Areas were classified asbeing under medium threat if within 40 kilometers of acity of one million or more, or within 60 kilometers of acity of five million or more.

Settlements: Population centers of less than 100,000 canalso present a significant threat to coral reefs. ThePopulated Place data set from the Digital Chart of theWorld (DCW) by the U.S. Defense Mapping Agency(DMA) and the Environmental Systems Research Institute(ESRI) was used to reflect settlements of any size. Thereare more than 206,000 settlement locations represented,with about 60,000 of these within the 60-kilometercoastal zone. Areas were classified as being under medi-um threat if within 8 kilometers of a settlement.

Airports and Military Bases: Airports and military basesare potential stressors to coral reefs directly, as a result of


TECHNICAL NOTES

*Low and lower-middle income countries include Algeria, Angola,Bangladesh, Benin, Cambodia, China, Colombia, Congo, Cuba,Dominican Republic, Egypt, Ghana, Guyana, India, Indonesia, Iran,Iraq, Jamaica, Lebanon, Morocco, Mozambique, Nigeria, Pakistan,Panama, Peru, Philippines, Republic of Korea, Saudi Arabia, Senegal,Sri Lanka, Sudan, Tanzania, Venezuela, Vietnam, and Yemen. Upper-middle and high income countries include Australia, Brazil, Chile,Curacao, Gabon, Guam, Hong Kong, Japan, Malaysia, Mexico, NewZealand, Puerto Rico, Saint Lucia, Singapore, South Africa, St.Thomas, Taiwan, Thailand, Trinidad, United Arab Emirates, and theUnited States.

construction, renovations, and emissions, and alsoindirectly, through the increased activities associated withthe transit of people and goods. The 8,235 military andcivilian airports from the DCW were used for this analy-sis, supplemented by military bases that were added tothe maps at the two-day Reefs at Risk workshop held inSeptember 1997 in Manila. Areas were classified as beingunder medium threat if within 10 kilometers of an air-port or military base.

Mines: Sedimentation and pollution associated withmining can present a significant threat to coral reefs. TheDCW data set on mines, including 8,515 mines that areundifferentiated by type, served as the base data set. Thiswas supplemented by eight mine locations added tomaps at the expert workshop. Areas were classified asbeing under high threat if within 10 kilometers of amine.

Tourist Resorts: Tourism represents threats to coralreefs—and their potential salvation. Types of tourism andresorts vary widely. The philosophies of the owner andguests, the resort design, and the care taken in implemen-tation all affect whether a tourist site or resort will be abenefit or harm to nearby coral reefs.

The data set used to evaluate areas likely to be underthreat from tourism is based upon resort and dive facilitylocations and areas of known impact to coral reefs fromtourism. A data set of 628 locations was assembled fromReefBase’s Lodging Facilities (232) and Dive Facilities (207)data sets, ReefBase’s known locations of reefs impacted bytourism (131), and additional resort locations that wereadded to maps at the expert workshop (58).

Areas were classified as being under medium threat ifwithin 8 kilometers of a tourist resort or location ofknown impact.

Embayments: Pollution and sediment entering enclosedareas such as bays and lagoons will not flush out as easilyas in open areas and can result in an elevated threat tocoral reefs. A data set of 650 embayments in areas nearcoral reefs was developed. Areas classified as being undermedium risk from any of the above coastal developmentstress factors that were also identified as an embaymentwere reclassified as being under high threat.

Implementation of the Marine-based Pollution Threat Factor

Proxies were developed to reflect the likely threat associ-ated with pollution from oil rigs, tanks, and wells andfrom ports, as well as the threat to reefs from shipping.

Ports: Large- and medium-sized ports, as defined bythe U.S. Defense Mapping Agency’s World Port Index(1994) were used in this analysis. Additionally, anumber of ports were added based upon input fromour reef experts at the Manila workshop. These addi-tional ports were treated as small ports in the analysis. There were 125 large, 288 medium, and 61small ports.

Areas were classified as being under high threat ifwithin 20 kilometers of a large port or 10 kilometers ofa medium-sized port. Areas were classified as beingunder medium threat if within 50 kilometers of a largeport, 30 kilometers of a medium-sized port, or 10 kilo-meters of a small port.

Oil-related Threats: Information on oil wells and oiltanks come from the DCW. The locations of severaladditional oil wells were added by experts at the work-shop. There were 794 oil wells and 134 oil tanks in theDCW data sets, while 13 points representing oil welllocations were added.

Areas were classified as being under high threat ifwithin four kilometers of an oil tank or well and undermedium threat if within 10 kilometers of an oil tank orwell.

Shipping-related Threats: Areas of intense shippingtraffic pose threats to reefs from discharges, spills, andpotential groundings. Although most of the world’soceans are crisscrossed at one time or another by ves-sels, many areas experience a much heavier volume oftraffic, and this can be particularly acute in areas ofnarrow passage or narrow channels.

Areas were defined as “shipping threat areas” if theyare along known shipping routes and have relativelynarrow areas for passage or have adjacent shallow reefs.These areas, as revised by reef experts at the Manilaworkshop, were classified as being under mediumthreat.

Implementation of the Overexploitation Threat Factor

Proxies were developed to reflect the likely threat frompopulation-driven overfishing and destructive fishingpractices (dynamite fishing, fishing using poisons, andtrawling).

Overfishing: Only countries where the per capita grossnational product is less than $10,000 per year or theper capita fish consumption is greater than 50 kilo-grams per year were considered. (In considering coastalcountries with or near coral reefs, Australia, the


Bahamas, Hong Kong, Israel, New Zealand, Singapore,and the United States were excluded. Japan was notexcluded because the per capita fish consumptionexceeds 50 kilograms per year.)

For all other countries, high threat areas were identi-fied as being within 20 kilometers of coastal areaswhere the population density exceeds 100 persons persquare kilometer, and medium threat areas were identi-fied as being within 20 kilometers of coastal areaswhere the population density exceeds 20 persons persquare kilometer. The medium-resolution global dataset Gridded Population of the World, from theNational Center for Geographic Information andAnalysis–Global Demography Project, was used to rep-resent population density.

Destructive Fishing Practices: The original estimationof areas under high threat from destructive fishing wasdefined as being within a 20-kilometer radius of a knownoccurrence of dynamite or cyanide fishing, as reflected inReefBase. This estimate has since been revised (bothexpanded and reduced in a few areas) based upon expertinput, obtained at the Manila workshop. These revisedareas were classified as under high threat.

Implementation of the Inland Pollution and ErosionThreat Factor

The inland pollution threat factor is analytically morecomplicated than the other factors. Hydrologic model-ing and geographic overlay analysis were used to incor-porate information on topography, land use, and pre-cipitation. There are three main steps to the method.

In the first step of the analysis, a surface reflectingrelative erosion potential (REP) was developed basedupon slope, land-cover type, and mean monthly pre-cipitation for the peak rainfall month. The variablereflecting land cover type was reclassified based upon arelative erosion rate derived from the literature andapplied as follows to the land cover classes used by theInternational Geosphere-Biosphere Program (IGBP).(See Table 4.)

The analysis was performed at one-kilometer resolu-tion for small islands and at three-kilometer resolutionfor continental areas. The formula for REP is:

REP = Slope 1.5 * Relative_Erosion_Rate *Precipitation / 1000

Slope is in percent slope, Relative Erosion Rate isdefined in Table 4, and Precipitation reflects mean

monthly precipitation for the peak rainfall month dur-ing the year in millimeters.

In the second part of the analysis, the REP surfacewas aggregated by watershed through the use of a sum-mary statistic for the watershed. Mean REP for thewatershed was used to classify watersheds as low, med-ium, or high REP. For coastal watersheds, this classifica-tion defines the level of threat from sedimentation.

In the third part of the analysis, the relevant zone ofeffect for sediment delivery was estimated.* Flow accu-mulation within the watershed, weighted by rainfall forthe peak rainfall month, was estimated for each water-shed and was used as a proxy for flow (discharge) at thecoastal pour point. This flow estimate was the basis forscaling the circular buffers reflecting zone of effect.†Information on plume distances for 20 rivers of theworld was used as the basis for this scaling. The estimatedplume area for each river was classed according to thethreat classification from step 2.

To summarize the implementation of the inland pol-lution threat factor: At coastal river mouths, a zone of


*As the range of nutrient plumes into the marine realm is far beyondthe range of effects of sedimentation (Hallock, Muller-Karger andHalas, 1993, National Geographic Research and Exploration,9:358–78) this method might underestimate the zone of effect.

†It is recognized that it would be ideal to take ocean currents intoaccount when estimating the sediment plume, or zone of effect, butthis was not possible within this global-scale analysis due to the lackof a sufficiently detailed global data set on ocean currents. Notincluding ocean currents in the analysis will serve to overestimate thezone of effect, but mostly offshore, where reefs typically do notoccur. As such, exclusion of this variable should not significantlyaffect the classification of threat to reefs.

Category Relative Erosion RateWater body 0.5

Evergreen broadleaf forest 1.0

Evergreen needleleaf forest 1.5

Deciduous needleleaf 2.0

Closed shrub land 4.0

Open shrub land 5.0

Woody savanna 6.0

Savannas 8.0

Permanent wetlands 8.0

Croplands/natural mix 12.0

Grasslands 12.5

Croplands 21.0

Urban and built up 21.0

Barren or sparsely vegetated 21.0

Table 4. IGBP Land Cover Categories With AssociatedRelative Erosion Rates

potential impact from inland (upstream) land-use activi-ties was developed based upon the relative estimate offlow within the watershed, while the degree of threat(low, medium, or high) is based upon the mean estimateof REP for the watershed. The REP itself is a function ofslope, land cover, and mean precipitation for the peakrainfall month for that area.

There were 3,260 pour points (discharge points) in theglobal analysis. The mean REP for the watersheds abovethese pour points was 41.7, the median was 12.5, and themaximum was 1,412. REP is a unitless value reflectingthe relative erosion potential for a land surface area. ■ watersheds with a mean REP of less than 5 were clas-

sified as under low threat;■ watersheds with a mean REP between 5 and 45 were

classified as under medium threat; and■ watersheds with a mean REP above 45 were classified

as under high threat. River flow estimates are also in unitless, relative terms.

The river flow estimate for coastal pour points have amean of 566, a median of 40.8, and a maximum (for theAmazon) of 204,600.

Table 5 summarizes the modeled river flow estimatesand the associated plume distances (zone of effect)implemented.

Accuracy IssuesThe Reefs at Risk indicator was implemented using thebest available global data sets. (The 14 data sets used aredescribed above.) The data sets are of varying spatialaccuracy and completeness, and reflect slightly differenttime periods. For example, the data sets from the DCWreflecting settlements, oil wells, and mines were devel-oped during the 1970s and 1980s, and were largelyrevised during the late 1980s. Recently developed oilwells or mines would be missing from the data sets.Information on tourist resorts from ReefBase is part of an

ongoing data development effort and, as such, is notcomprehensive. Additionally, the spatial accuracy of thesedata sets varies from better than one kilometer for thedata sets from the DCW, the land cover and topographicdata sets, to up to several kilometers for some of the datain ReefBase, the World Cities Data Base, and the popula-tion density data. The spatial accuracy issues associatedwith using this range of data sets is mitigated throughaggregating all data to a standard four-kilometer resolu-tion grid, consistent with the four-kilometer resolutiondata set reflecting shallow coral reefs from the WorldConservation Monitoring Centre. The analysis was imple-mented at four-kilometer resolution.

Regional GroupingsWithin the Reefs at Risk analysis, regional summary statistics were based on the regional groupings aspresented in the map below.


River Flow (000) Plume (km) Number of Occurrences

0–10 15 544

10–20 25 569

20–30 40 296

30–100 50 838

100–200 60 366

200–400 70 244

400–1,000 80 206

1, 000–2,000 90 88

2,000–5,000 100 57

5,000–20,000 120 30

20,000–40,000 140 8

40,000–100,000 160 7

over 100,000 200 1

Table 5. River Flow Estimates and Associated PlumeDistances

MAP 7.


The Reefs at Risk analysis reflects modeled esti-mates of threats to coral reefs and is driven bydata sets reflecting population density, humanpopulation centers, infrastructure and activities,and our derived estimates of threats from inlandpollution and sedimentation. These estimatesshould not be taken to reflect current reef con-dition, nor should they be taken to reflect allknown threats to coral reefs. Estimation ofthreats to reefs was particularly difficult forremote areas in the Pacific, which are less visi-ted and for which global data sets tend to be less complete.

During review of these final threat classifications,coral reef experts provided the following observations:

Tropical Americas 1. The Florida Keys reefs are classified as undermedium threat from marine pollution and coastaldevelopment. This is regarded as a potential under-estimate of threat.2. The reefs off southern Belize are classified asbeing under high threat, largely from inland pollu-tion and erosion. This is regarded as a potentialoverestimate of threat, relative to other reefs in thatregion. 3. The reefs off western Costa Rica were estimatedto be under high threat from coastal developmentand inland pollution and erosion. One researchersuggested that this overestimates threat in that area.4. Bermuda’s reefs are classified as being underhigh threat from overexploitation. This is an over-estimate of current threat since the pot fishingindustry was closed in 1990.

Indian OceanThe reefs in the northeastern Seychelles aroundMahé and Curieuse Islands were estimated to beunder medium and high threat. This is a potentialoverestimation of threat.

Seas of the Middle East1. Within the Gulf of Aqaba, reefs were estimatedto be approximately 70 percent under low threatand 30 percent under high threat, largely fromcoastal development. This is regarded as a potentialunderestimate due to the threats posed by tourismand shipping.2. Along the coast of Yemen, most reefs were esti-mated to be under high threat from overexploita-tion. This is regarded as a potential overestimationof threat, relative to other reefs in the region.

East AsiaThe Spratly Islands have been classified predomi-nantly as under low threat. This is probably anunderestimate due to blast fishing, fishing withpoisons, and shark fishing in that area.

Pacific Ocean1. New Caledonia’s reefs are estimated to be pre-dominantly under low threat. This was noted to bea potential underestimate for the reefs of the mainisland due to deforestation and mining contribut-ing to sedimentation.2. The reefs of Christmas Island were classified asbeing under high threat. Medium was suggested asa more appropriate estimate of threat for this atoll. 3. Within Micronesia, the reefs of Majuro andKwajalein were classified as being under low threat,which may be an underestimate of the threat fromcoastal development activities.

Comments on the Reefs at Risk

Indicator


Work on mapping the distribution of coral reef fish species is ongoing. This analysis draws onwork by the University of York and Ocean VoiceInternational, which mapped the ranges of approx-imately 1,677 coral reef fish species from 29 fami-lies. Species ranges were identified using a broadarray of data from more than 350 monographs, sci-entific literature, museum records, and field collec-tion. These data were entered as map points (over33,000 points) and have been summarized intoequal-area grid cells (4,500 distinct areas) coveringapproximately 50,000 square kilometers each. Thissample represents about 40 percent of all knowncoral reef fishes.

The surveying and sampling of coral reef fishspecies is uneven across the globe. For example, agreater proportion of species have been sampledin the Caribbean relative to the Red Sea, someparts of Southeast Asia, and remote areas of the

Pacific. This sampling bias favors the inclusion ofwell-sampled areas. As such, several areas likely tohave species diversity comparable to areas in theCaribbean were not included in the analysis,including the reefs off the coast of Vietnam, theSpratly Islands, and parts of the Red Sea.

In order to reduce the sampling bias in the identifi-cation of areas with high coral reef fish speciesdiversity, interpolated, smoothed species rangeswhich summarize the number of species within anapproximately 400-kilometer radius were used.Areas in the top 20 percent for species diversity(with at least 210 coral reef fish species) were iden-tified. These areas were then classified according tothe estimate of potential threat to coral reefs fromhuman activity (the Reefs at Risk indicator) for allreefs within each area.

Analysis of Species Diversity

and Threats to Coral Reefs

About the Authors:Dirk Bryant is a Senior Associate in the WRIInformation Program and is the principal author ofThe Last Frontier Forests: Ecosystems and Economies on theEdge, the first global study on the status of frontierforests—the large, ecologically intact, and relativelyundisturbed natural forests that still remain. He hasdone extensive work on the development of environ-mental indicators, including coastal pressure indicators,and currently manages the Global Forest Watch pro-ject—an independent, decentralized global monitoringnetwork developed as a collaborative effort amonglocal, national, regional and international partners.

Prior to joining WRI, Mr. Bryant conducted forestecology fieldwork in Belize for the Jet PropulsionLaboratory, was employed as a naturalist forMassachusetts Audubon, and served as a Peace Corpsfisheries volunteer in Senegal, West Africa. He has aMasters degree in Environmental Management fromDuke University.

Lauretta Burke is a Senior Associate in the InformationProgram of the World Resources Institute. Trained as anenvironmental policy analyst and geographic informa-tion systems (GIS) specialist, she focuses on the devel-opment of improved information tools to supportenvironmentally sustainable development. Prior tojoining WRI, Ms. Burke implemented a GIS in Guyanato support urban infrastructure rehabilitation planning;managed the development of integrated GIS data setsfor 53 African countries; established a GIS for theEnvironmental Studies program of the CentralEuropean University; and performed analysis on theimpact of potential climate change on fisheries, wet-lands and biological diversity for U.S. EPA’s GlobalClimate Change Program.

Dr. John William McManus is a marine ecologist spe-cializing in fisheries, coral reefs, biogeography, commu-nity ecology and coastal zone management. He com-pleted his PhD in Biological Oceanography at theUniversity of Rhode Island. Dr. McManus is currently asenior scientist at the International Center for LivingAquatic Resources Management (ICLARM). As currentleader of the Aquatic Environments Program, he super-vises work on the following projects: ReefBase: TheGlobal Database on Coral Reefs and their Resources;Population Interdependencies in the South China SeaEcosystem (PISCES); the Coastal Management TrainingProject; and the Population, Consumption andEnvironment Project.

Mark Spalding is the Marine Research Officer with theWorld Conservation Monitoring Centre, and a researchassociate with the Cambridge Coastal Research Unit,University of Cambridge. He has been working on coralreefs and particularly on reef mapping for the last fiveyears, and has recently completed a PhD thesis with aparticular focus on marine biodiversity mapping in thetropics. He coordinates the coral reef mapping work forReefBase, and recently compiled and edited the WorldMangrove Atlas, a global review of the distribution ofmangrove forests.



ENDNOTES 1 Don McAllister, “Status of the World Ocean and Its

Biodiversity,” Sea Wind 9, no. 4 (1995), 14.

2 Clive Wilkinson, “Coral Reefs Are Facing WidespreadDevastation: Can We Prevent This Through SustainableManagement Practices?” in Proceedings of the 7th InternationalCoral Reef Symposium 1 (Guam, 1993), 11–21.

3 Elizabeth Pennisi, “Brighter Prospects for the World’sCoral Reefs?” Science 277 (July 25, 1997), 492.

4 Robert Costanza et al., “The Value of the World’sEcosystem Services and Natural Capital,” Nature 387 (May15, 1997), 256.

5 Gustav Paulay, “Diversity and Distribution of ReefOrganisms,” in Life and Death of Coral Reefs, ed. CharlesBirkeland (New York: Chapman and Hall, 1997), 303–4.

6 David Malakoff, “Extinction on the High Seas,”Science 277 (July 25, 1997), 487–88.

7 Elliot Norse, ed., Global Marine Biological Diversity: AStrategy for Building Conservation into Decision Making(Washington, D.C.: Island Press, 1993), 14.

8 United Nations Environment Programme (UNEP)and World Conservation Union (IUCN), Coral Reefs of theWorld. Volume 1: Atlantic and Eastern Pacific (Gland,Switzerland: IUCN, 1988), xvi.

9 Mark Spalding and A. M. Grenfell, “New Estimates ofGlobal and Regional Coral Reef Areas,” Coral Reefs (1997)16:225–230.

10 Clive Wilkinson and Robert Buddemeier, GlobalClimate Change and Coral Reefs: Implications for People andReefs (Gland, Switzerland: IUCN, 1994), 6.

11 James E. Maragos, M. P. Crosby, and John W.McManus, “Coral Reefs and Biodiversity: A Critical andThreatened Relationship,” Oceanography 9, no. 1 (1996), 87.

12 Les Kaufman and Paul Dayton, “Impacts of MarineResources Extraction on Ecosystem Services andSustainability,” in Nature’s Services: Societal Dependence onNatural Ecosystems, ed. Gretchen Daily (Washington, D.C.:Island Press, 1997), 275.

13 Stephen C. Jameson, John W. McManus and Mark D.Spalding, State of the Reefs: Regional and Global Perspectives(Washington, D.C. ICRI., U.S. Department of State, 1995),24.

14 Donald Hinrichsen, “Requiem for Reefs?”International Wildlife (March/April 1997), 8.

15 Herman Cesar, Economic Analysis of Indonesian CoralReefs (Washington, D.C.: World Bank, 1996), 4, 16.

16 Charles Birkeland, ed., Life and Death of Coral Reefs(New York: Chapman and Hall, 1997), 5.

17 William Fenical, “Marine Biodiversity and theMedicine Cabinet: The Status of New Drugs from MarineOrganisms,” Oceanography, 9, no. 1 (1996), 23–24.

18 Maragos, Crosby, and McManus, “Coral Reefs andBiodiversity,” 85–7.

19 Birkeland, Life and Death of Coral Reefs, 4.

20 Jameson, McManus, and Spalding, State of the Reefs, 24.

21 Herman Cesar, Economic Analysis of Indonesian CoralReefs (Washington, D.C.: World Bank, 1996).

22 Robert Richmond, “Coral Reef Resources: Pollution’sImpacts,” Forum for Applied Research and Public Policy 9, no. 1(Spring 1994), 55–56.

23 Mats Bjork, Salim Mzee Mohammad, MarieBjorkland, and Adelaida Semesi, “Coralline Algae, ImportantCoral Reef Builders Threatened by Pollution,” Ambio 24, nos.7–8 (December 1995), 502–4.

24 Barbara Brown, “Disturbances to Reefs in RecentTimes,” in Life and Death of Coral Reefs,” ed. CharlesBirkeland (New York: Chapman and Hall, 1997), 370–72.

25 Global Environment Facility, The Hashemite Kingdomof Jordan: Gulf of Aqaba Environmental Action Plan(Washington, D.C.: World Bank, 1996), 5.

26 James Bohnsack, “The Impacts of Fishing on CoralReefs,” in Proceedings of the Colloquium on Global Aspects ofCoral Reefs: Health, Hazards and History (University of Miami,1993), 196–98.

27 Simon Jennings and Nicholas Polunin, “Impacts ofFishing on Tropical Reef Ecosystems,” Ambio 25, no. 1(February 1996), 44–46.

28 Callum Roberts, “Effects of Fishing on the EcosystemStructure of Coral Reefs,” Conservation Biology 9, no. 5(October 1995), 989–92.

29 Pennisi, “Brighter Prospects.”

30 Gomez, Alino, Yap, and Licuanan, “A Review of theStatus of Philippine Reefs,” Marine Pollution Bulletin 29, nos.1–3 (1994), 65–66.

31 Jorge Cortes, “A Reef Under Stress: A Decade ofDegradation,” in Proceedings of the Colloquium on GlobalAspects of Coral Reefs: Health, Hazards and History (Universityof Miami, 1993), 240–45.

32 L. Talaue–McManus and K. P. N. Kesner, “Valuation ofa Philippine Municipal Sea Urchin Fishery and Implicationsof Its Collapse,” in Philippine Coastal Resources ManagementUnder Stress, eds. M. A. Juinio–Menez and G. F. Newkirk(Quezon City: Coastal Resources Research Network andMarine Sciences Institute, University of the Philippines,1995), 229–39.

33 R. E. Johannes and M. Riepen, Environmental,Economic and Social Implications of the Live Fish Trade in Asiaand the Western Pacific (Bonnet Hill, Tasmania, Australia; REJohannes Pty Ltd and Wellington, New Zealand: FisheriesDevelopment Associates, 1995).

34 Brown, “Disturbances to Reefs,” 365.

35 C. M. Eaken, “Where Have all the Carbonates Gone?


A Model Comparison of Calcium Carbonate Budgets Beforeand After the 1982–1983 El Niño,” Coral Reefs 15, no. 2 (1Aqaba Environmental Action Plan (Washington D.C., WorldBank, 1996), 996), 109–19.

36 P. W. Glynn, “Coral Reef Bleaching: Facts, Hypothesisand Implications,” Global Change Biology 2, no. 6 (1996),495–509.

37 Callum Roberts, Nigel Downing and Andrew Price,“Oil on Troubled Waters: Impacts of the Gulf War on CoralReefs,” in Proceedings of the Colloquium on Global Aspects ofCoral Reefs: Health, Hazards and History (University of Miami,1993), 132–37.

38 UNEP/IUCN, Coral Reefs of the World. Volume 2: IndianOcean, Red Sea and Gulf (Gland, Switzerland: IUCN, 1988),xxi.

39 Brown, “Disturbances to Reefs,” 373–4.

40 Brown, “Disturbances to Reefs,” p. 376.

41 Joby Warrick, “Coral Reef off Florida Keys Caught inWave of Deadly Disease,” Washington Post, February 9, 1997,A3.

42 Rodney Salm, “The Status of Coral Reefs in theWestern Indian Ocean with Notes on Related Ecosystems,”working paper prepared for the International Coral ReefInitiative Workshop, Seychelles, March 1996.

43 Mark Spalding, Francois Blasco, and Colin Field, eds.,World Mangrove Atlas (Okinawa: International Society forMangrove Ecosystems, 1997), 11.

44 Wilkinson and Buddemeier, Global Climate Change,40, 103.

45 S. C. Jameson, J. W. McManus and M. M. Spalding,State of the Reefs: Regional and Global Perspectives (Washington,D.C.) I.C.R.I., U.S. Department of State, 1995), 6–7.

46 Jorge Cortes, “Status of the Caribbean Coral Reefs ofCentral America,” in Proceedings of the 8th International CoralReef Symposium (Balboa, Panama, Smithsonian TropicalResearch Institute, 1997), 339.

47 Rajasuriya, De Silva, and Ohman, “Coral Reefs of SriLanka: Human Disturbance and Management Issues,” Ambio24, nos. 7–8 (December 1995), 428–29.

48 Arjan Rajasuriya, “Present Status of Coral Reefs in SriLanka,” in Proceedings of the Colloquium on Global Aspects ofCoral Reefs: Health, Hazards and History (University of Miami,1993), 411.

49 Callum Roberts, Nigel Downing, and Andrew Price,“Oil on Troubled Waters: Impacts of the Gulf War on CoralReefs,” in Proceedings of the Colloquium on Global Aspects of CoralReefs: Health, Hazards and History (University of Miami, 1993),136.

50 Peter Weber, “Reviving Coral Reefs” in State of theWorld 1993 (Washington, D.C.: WorldWatch Institute, 1993)48.

51 Clive Wilkinson, personal communication. Reportingon results from the 1996 International Coral ReefSymposium.

52 Ewald Lieske and Robert Myers, Coral Reef Fishes:Caribbean, Indian Ocean and Pacific Ocean Including the RedSea (Princeton, N.J.: Princeton University Press, 1996), 7.

53 Cesar, Economic Analysis, 25.

54 Gomez, Alino, Yap, and Licuanan, “Philippine Reefs,”64.

55 J. E. Maragos and C. Payri, “The Status of Coral ReefHabitats in the Insular South and East Pacific,” in Proceedingsof the 8th International Coral Reef Symposium (Balboa, Panama:Smithsonian Tropical Research Institute, 1997), 311.

56 Leon Zann, “The Status of Coral Reefs in SouthWestern Pacific Islands,” Marine Pollution Bulletin 29, nos. 1–3(1994), 53–55.

57 E. Dinerstein, D. M. Olson, D. J. Graham, A. L.Webster, S. A. Primm, M. P. Bookbinder and G. Ledec, AConservation Assessment of the Terrestrial Ecoregions of LatinAmerica and the Caribbean (Washington, D.C.: World Bankand the World Wildlife Fund, 1995).

58 Nels Johnson, Biodiversity in the Balance: Approaches toSetting Geographic Conservation Priorities (Washington, D.C.:Biodiversity Support Program, 1995), 9.

59 William Smith-Vaniz, James Bohnsack, and JamesWilliams, “Reef Fishes of the Florida Keys,” in Our LivingResources: A Report to the Nation on the Distribution, Abundance,and Health of U.S. Plants, Animals and Ecosystems (U.S.Department of Interior), 279.

60 UNEP/IUCN, Coral Reefs of the World. Volume 1,311–15.

61 Ibid., 251–52.

62 H. M. Guzman, J. B. C. Jackson, and E. Weil,“Short–term Ecological Consequences of a Major Oil Spill onPanamanian Subtidal Reef Corals,” Coral Reefs 10 (1991),1–12.

63 H. M. Guzman and I. Holst, “Effects of ChronicOil–sediment Pollution on the Reproduction of theCaribbean Reef Coral Siderastrea Sidera,” Marine PollutionBulletin 26 (1993), 276–82.

64 H. M. Guzman, K. A. Burs, and J. B. C. Jackson,“Injury, Regeneration and Growth of Caribbean Coral ReefCommunities After a Major Oil Spill in Panama,” in MarineEcology Program Series 105 (1994), 231–41.

65 UNEP/IUCN, Coral Reefs of the World. Volume 1, 177.

66 K. Nakatani, A. Rajasuriya, A. Premaratne, and A. T.White, eds., The Coastal Environmental Profile of Hikkaduwa, SriLanka (Colombo, Sri Lanka: Coastal Resources ManagementProject, 1994).

67 A. Rajasuriya and A. T. White, “Coral Reefs of SriLanka: Review of Their Extent, Condition and Management


Status,” Coastal Management 23 (1995), 77–90.

68 A. T. White, V. Barker, and G. Tantrigama, “UsingIntegrated Coastal Management and Economics to ConserveCoastal Tourism Resources in Sri Lanka,” Ambio 26, no. 6(1997), 335–44.


70 Stephen Jameson and David Smith, “Coral ReefManagement on the New Red Sea Riviera,” Proceedings ofCoastal Zone 1997 2 (1997), 784–86.


72 L. M. Chou, “The Status of Southeast Asian CoralReefs,” in Proceedings of the 8th International Coral ReefSymposium (Balboa, Panama: Smithsonian Tropical ResearchInstitute, 1997), 317.

73 UNEP/IUCN, Coral Reefs of the World. Volume 2,307–9.

74 J. W. McManus and M. C. Ablan, eds., ReefBase: AGlobal Database on Coral Reefs and Their Resources. User’s Guide.Version 2.0 (Makati City, Philippines: International Center forLiving Marine Aquatic Resources, 1997).

75 P. J. Mumby, E. P. Green, A. J. Edwards, and C. D.Clarke, Coral Reef Habitat Mapping: How Much Detail CanRemote Sensing Provide? (in press).

76 D. L. B. Jupp, “Background and Extensions to DepthPenetration Mapping in Shallow Coastal Waters,” paper pre-sented at the Symposium on Remote Sensing of the CoastalZone, Gold Coast, Queensland, Australia, 1988.

77 Mumby, Green, Edwards, and Clark, Coral Reef HabitatMapping.

78 D. Hopley and P. C. Catt, “The Use of Infrared AerialPhotography for Monitoring Ecological Changes to CoralReef Flats on the Great Barrier Reef,” in Proceedings of the 6thInternational Coral Reef Symposium (Townsville, Australia,1988), 503–8.

79 J. W. McManus et al., “Coral Reef Fishery SamplingMethods,” in Stock Assessment: Qualitative Methods andApplications for Small–Scale Fisheries, eds. V. F. Galluci et al.(New York: CRC Lewis Publishers, 1996).

80 D. Hopley, Aerial Photography and Other RemoteSensing Techniques. In Coral Reefs: Research Methods, eds. D.R.Stoddard and R.E. Johannes (Paris: UNESCO), 231–50

81 Mumby, Green, Edwards, and Clarke, Coral ReefHabitat Mapping.

82 Hopley and Catt, “Use of Infrared AerialPhotography.”

83 Hopley, “Aerial Photography.”

84 McManus et al., “Coral Reef Fishery SamplingMethods.”

85 D. C. Rhoads, J. A. Muramoto, and R. Ward, A Reviewof Sensors Appropriate for Efficient Assessment of SubmergedCoastal Habitats and Biological Habitats, Technical ReportEL–96 (Vicksburg, Miss.: U.S. Army Corps of Engineers,1996).

86 R. D. McCaughley, “The Sounds of Coral Reefs” JointConference on Science, Management and Sustainability in the 21stCentury. Abstracts. (Townsville, Australia: James CookUniversity of North Queensland, 1994), 49.

87 Rhoads, Muramoto, and Ward, Review of Sensors.

88 Charles H. Mazel, personal communication.

89 Alan White, personal communication.

90 James Butler, James Burnett–Herkes, John Barnes, andJack Ward, “The Bermuda Fisheries: A Tragedy of theCommons Averted?” Environment 35, no. 1 (1993), 8–13.

91 Birkeland, Life and Death of Coral Reefs, 428.

92 Butler, Burnett–Herkes, Barnes and Ward, “TheBermuda Fisheries,” 7–32.

93 Yasmin Arquize and Alan White, Tales from Tubbataha:Natural History, Resource Use, and Conservation of the TubbatahaReefs Palawan Philippines (Bandillo ng Palawan Foundation,Philippines, 1994).

94 Alan White and V. P. Palaganas, “PhilippineTubbataha Reef National Marine Park: Status, ManagementIssues and Proposed Plan,” Environmental Conservation 18, no.2 (1991), 148–57.

95 Great Barrier Reef Marine Park Authority, World Bank,and World Conservation Union, A Global Representative Systemof Marine Protected Areas. Volume II: Wider Caribbean, WestAfrica and South Atlantic, eds. Graeme Kelleher, Chris Bleakleyand Sue Wells (Washington, D.C.: World Bank, 1995), 7.

96 World Conservation Union (IUCN), “Parks for Life, ANew Beginning” IUCN Bulletin 23, no.2 (1992), 10.

97 Will Hildesley, “Marine Protected Areas: WWF’s Rolein Their Future Development,” draft WWF International dis-cussion document (Gland, Switzerland, February 1998).

98 A. Charlotte de Fontaubert, David Downes, and TundiAgardy, Biodiversity in the Seas: Implementing the Convention onBiological Diversity in Marine and Coastal Habitats (Gland,Switzerland: World Conservation Union, 1996).

99 National Oceanic and Atmospheric Administration’sReporter’s Coral Reef Tip Sheet, June 2, 1997.

100 David Downes and A. Charlotte de Fountaubert,“Biodiversity in the Seas: Conservation and Sustainable UseThrough International Cooperation,” CIEL Brief (Center forInternational Environmental Law, no. 4, October 1996), 5.

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interaction with economic development and social equity at all levels.

The Institute’s current areas of work include economics, forests, biodi-

versity, climate change, energy, sustainable agriculture, resource and

environmental information, trade, technology, national strategies for

environmental and resource management, business liaison, and human

health.

In all of its policy research and work with institutions, WRI tries to

build bridges between ideas and action, meshing the insights of scientific

research, economic and institutional analyses, and practical experience

with the need for open and participatory decisionmaking.

WORLD RESOURCES INSTITUTE

1709 New York Avenue, N.W.

Washington, D.C. 20006, USA

http://www.wri.org/wri

World Resources Institute1709 New York Avenue, N.W.Washington, D.C. 20006 USA

http://www.wri.org/

ISBN: 1-55963-257-4

WORLD CONSERVATIONMONITORING CENTRE

WORLD RESOURCESINSTITUTE

INTERNATIONAL CENTERFOR LIVING AQUATIC

RESOURCES MANAGEMENT

UNITED NATIONSENVIRONMENT PROGRAMME

Documents

Reefs at Risk - University of Floridaufdcimages.uflib.ufl.edu/UF/00/09/58/88/00001/reefs.pdfREEFS AT RISK A Map-Based Indicator of Threats to the World’s Coral Reefs D IRK B RYANT•