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Status and Interconnections of Selected Environmental Issues in the GlobalCoastal ZonesAuthor(s): Hua Shi and Ashbindu SinghSource: AMBIO: A Journal of the Human Environment, 32(2):145-152. 2003.Published By: Royal Swedish Academy of SciencesDOI: http://dx.doi.org/10.1579/0044-7447-32.2.145URL: http://www.bioone.org/doi/full/10.1579/0044-7447-32.2.145

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145Ambio Vol. 32 No. 2, March 2003 © Royal Swedish Academy of Sciences 2003http://www.ambio.kva.se

Article

INTRODUCTION“Bright spots” are concentrations of light emitted into space fromcities and towns, and observable in nighttime satellite imagesof the earth. They are located primarily in coastal zones and pro-vide a good depiction of the earth’s population distribution (1).Coastal zones contain diverse habitats, major settlements, andareas of significant resources. Coastal resources are vital to manylocal communities and indigenous people. Coastal zones havebeen key for transporting goods, people, and ideas because seatrade is less costly than land- or air-based trade (2). The beautyof coastal zones makes them a magnet for many people. Peoplegravitate to coastal zones to live and work, as well as for lei-sure, recreational activities, and tourism. Encompassing a broadrange of habitat types and harboring a wealth of species, coastalecosystems store and cycle nutrients, filter pollutants, form in-land freshwater systems, and help to protect shorelines from ero-sion and storms (3). Coastal zones are home to the oceans’bounty (4).

The issues and problems associated with coastal resources,environment, population, and their current or potential relation-ship to sustainable development, have continued to receive a highlevel of national and international attention (5). Headlines drawattention to many diverse subjects, including rising sea level,coastal erosion, changing storm frequency, urbanization, thelosses of coastal wetland and coastal biodiversity, and marinepollution. However, coastal zones are under significant threatsdue to impact of climate variability and other potential globalchanges. The adverse effects of increasing population and hu-man activities on the environment are dramatically accumulat-ing, which is threatening the very foundation of sustainable de-velopment (6). Impact of human activities in the coastal zoneshas received increasing recognition as a significant factor in en-vironmental protection. The United Nations, in the Agenda 21from the Earth Summit, Rio de Janeiro 1992, “sets forth rightsand obligations of States and provides the international basisupon which to pursue the protection and sustainable develop-ment of the marine and coastal environment and its resources.

This requires new approaches to marine and coastal areas man-agement and development, at the national, sub-regional, regionaland global levels” (7). Continued modification and destructionof the world’s coastal zone will gravely endanger its ability toprovide fish, protect homes and businesses, reduce pollution anderosion and sustain biodiversity (8), “Unless things change veryquickly, the world’s coastal areas face a grim future,” said in-stitute president Jonathan Lash (WRI release). Russian geogra-phers have developed “red data maps” of the entire globe to des-ignate areas of “critical environmental situations” for global en-vironmental issues (9). Environmental vulnerability in coastalzones should be viewed in this same way, by being recognizedas a global issue and utilizing a broader perspective. Most stud-ies related to coastal zones have generally dealt with “site spe-cific issues” examining small areas or focusing on individual is-sues. Consequently, the extrapolation of results of such studiesto large areas has been limited in scope. The vulnerability ofcoastal zones should be analyzed utilizing a more holistic per-spective. A broader geographic perspective of the coastal envi-ronment is therefore needed to clearly reveal status and connec-tions among various interacting factors. This perspective, in turn,could provide a foundation for studying environmental issues ofglobal coastal zones, and would provide a scientific basis forcoastal zone management.

The objectives of this study are: i) to quantify some complexrelationships between population and coastal zone environments;and ii) to support decision making and policy development us-ing consistent and comprehensive geospatial data sets employ-ing Geographic Information System (GIS) technology. The studyassesses the interconnections between population dynamics, landcover distribution, large cities, protected areas, and biodiversityhotspots in global coastal zones that are likely to be impactedby significant environmental changes in the future.

In the past, similar analyses have usually been performed bythe aggregation of statistical data compiled by administrativeunits using a variety of sources. These datasets vary consider-ably in quality and geographic coverage. The simple mergingof these individual datasets does not meet the needs of a moreholistic, regional and global-scale analysis. Some of thesedatasets are often old and based on different definitions and clas-sifications; hence, they are not comparable and difficult to ag-gregate. The analysis presented here uses globally consistent andcomprehensive geospatial datasets developed through interna-tional cooperation using remote sensing and other sources. Suchanalyses provide a scientifically credible environmental assess-ment covering large areas.

Since global coastal zones have the world’s highest popula-tion density, developed economies, and the most vulnerable en-vironment, it is expected that the information derived from suchanalyses could help to identify problems in the management ofcoastal ecosystems and, more importantly, provide for timely in-tervention to prevent further degradation of the coastal environ-ment.

DATA SOURCES AND METHODOLOGYThere are 3 principal differences between the present researchresult and those of earlier research results: i) The coastal zoneis defined in a consistent manner as land within 100 km of the

Hua Shi and Ashbindu Singh

This study focuses on assessing the state of populationdistribution, land cover distribution, biodiversity hotspots,and protected areas in global coastal zones. The coastalzone is defined as land within 100 km of the coastline. Thisstudy attempts to answer such questions as: how crowdedare the coastal zones, what is the pattern of land coverdistribution in these areas, how much of these areas aredesignated as protected areas, what is the state of thebiodiversity hotspots, and what are the interconnectionsbetween people and coastal environment. This study usesglobally consistent and comprehensive geospatial data-sets based on remote sensing and other sources. Theapplication of Geographic Information System (GIS) layer-ing methods and consistent datasets has made it possibleto identify and quantify selected coastal zones environ-mental issues and their interconnections. It is expected thatsuch information provide a scientific basis for global coastalzones management and assist in policy formulations at thenational and international levels.

Status and Interconnections of SelectedEnvironmental Issues in the Global CoastalZones

146 © Royal Swedish Academy of Sciences 2003 Ambio Vol. 32 No. 2, March 2003http://www.ambio.kva.se

buffer from coastline, excluding coastal zones of inland lakesand Antarctica; ii) The most comprehensive currently availableglobal spatial datasets developed through remote sensing andother source materials are used; and iii) Geographic InformationSystem (GIS) tools were used for analysis, integration, and visu-alization of results. The following 6 datasets were used in theanalysis.

Data Sources

i) Global Land Cover Distribution Data: In this study, the USGSland cover database (10) was used as a base to update forestcover maps for many parts of the world for the year 1995 usingthe FAO classification system (11). This land cover database wasbuilt on characteristics of vegetation seasonality determined interms of weekly composite of Normalized Difference Vegeta-tion Index (NDVI) derived from the NOAA AVHRR sensor forthe period 1992–1993 (http://edcdaac.usgs.gov/). In the database,unique NDVI signatures and associated attributes, such as ter-rain and ecoregions, characterize large-area land cover patterns(12). In this study, areas under forest cover classes, namely,closed forests (density > 40%), open and fragment forests (den-sity 10–40%), and other woodlands, were generated, whereas ar-eas under grassland, cultivation, and water were taken from theUSGS land cover database.

ii) Global Population Database: The geographically refer-enced population database was provided by the UNEP/GRID(http://www.na.unep.net). These datasets for 1990 were gener-ated using a model incorporating many variables. The globalpopulation statistical data were taken from the World ResourcesDatabase CD-ROM (2000, 2010, 2025, 2050) published by theWorld Resources Institute (WRI).

iii) Global Protected Area Database: UNEP-World Conser-vation Monitoring Center (http://www.unep-wcmc.org/) providedthe protected areas database. The definition of a protected areaas adopted by The World Conservation Union (IUCN) is “Anarea of land and/or sea especially dedicated to the protection andmaintenance of biological diversity, and of natural and associ-

ated cultural resources, and managed through legal or other ef-fective means” (13).

iv) Biodiversity Hotspots: Conservation International providedthe biodiversity hotspots database (http://www.conservation.org/). The hotspots are considered to be the earth’s biologicallyrichest and most endangered terrestrial ecoregions. ConservationInternational have identified the following 25 hotspots: Atlan-tic Forest region, Brazilian Cerrado, California Floristic Prov-ince, Cape Floristic Region Caribbean, Caucasus, Central Chile,Choco-Darien-Western Ecuador, Eastern Arc Mountains andCoastal Forest of Tanzania and Kenya, Guinean Forests of WestAfrica, Indo-Burma, Madagascar and Indian Ocean Islands,Mediterranean basin, Mesoamerica, Mountains of S. CentralChina, New Caledonia, New Zealand, Pilippines, Poynesia andMicronesia, Southwest Australia, Succulent Karoo, Sundaland,Tropical Andes, Wallacea, Western Ghats and Sri Lanka (14).

v) Political Boundaries Data: Political boundaries data weretaken from the US National Imagery and Mapping Agency’s(NIMA) Vector Map Level 0 (VMAP0) series CD-ROM. Thisdataset provides, among other things, the 1995 version of thepolitical boundaries of the world at a 1:1 million nominal scale.Attribute assignments were verified and corrected as needed forthe resulting polygon coverage and subsequently these coverageswere joined to generate an updated map.

vi) World’s Cities: The distribution of the world’s cities wastaken from Environmental Systems Research Institute Inc.(ESRI, http://www.esri.com), Data and Maps CD-ROMs.

General Considerations about the Data

The land cover and population datasets were the best availablecovering the entire world. Local errors are known to exist in themapped distribution of land cover type.

The population distribution dataset is generated using a spa-tial modally technique incorporating many variables.

The protected areas database is not current for all countries.Some of the smaller protected areas may not have been ac-counted for due to the coarse resolution of the data; e.g. where

Table 1. Population studies in coastal zone by different sources.

Source Author or Year Population Scope of Method of theorganization estimated coastal area study used

Agenda 21 (7) United Nations 1992 More than half, and 60 km Not clearthis could rise tothree quarters bythe year 2020

Coasts in Crisis (16) Don Hinrichsen 1995 54 % of 772 coastal counties Statistic dataAmericans

Protecting the United Nations 1991 Seven out 80 km Not clearOcean (4) Association of ten

in CanadaPopulation and NOAA 1998 133 million 673 coastal counties Statistic dataDevelopment in along Atlantic andCoastal Areas (25) Pacific Ocean, Gulf

of Mexico, andGreat Lakes

Population and Committee for 1998 60% population 60 km (37 miles) Not clearEnvironment the NationalLinkages: Ocean (24) Institute for the

EnvironmentHuman Domination P.M. Vitousek, 1997 60% population 100 km Not clearof Earth’s H.A. Mooney,Ecosystem (21) J. Lubchenco,

J.M. MelilloThe regional Impacts Watson, Zinyowera, 1997 50% population Not clear Not clearof Cimate Change: Moss and Dokken 1997An Assessment ofVulnerablity (26)Estimates of Coastal J.E. Cohen, C. Small, 1997 37% population 100 km Digital data/Population (27) A. Mellinger, J. Gallup No details

and J. SachsPeople and World Resources 2000 40% world’s 100 km GIS/No detailsEcosystems (36) Institute (WRI) populationCoastal: The Potential NOAA 2000 53% of total 17% of land in the Not clearof Climate Variability US population coastal zoneand Changes (5)

147Ambio Vol. 32 No. 2, March 2003 © Royal Swedish Academy of Sciences 2003http://www.ambio.kva.se

information is not available for the exact extent of a protectedarea, a point has been inserted representing the center of the site.Polygons were made for such locations by using the informa-tion in textual databases and drawing a circular polygon of therelevant area around the point location of the site. None of thesedatasets have been rigorously validated, so local relationshipsand distributions should be viewed with caution. Availability ofhigh-quality, current global data remains a barrier in such analy-ses, highlighting the need to support development and updatingof such databases.

Methodology

Data were processed using several Remote Sensing and GIS soft-ware systems (15). Most of the work was done in the GRID mod-ule of ARC/INFO. Raster and vector data layers were in an In-terrupted Goode Homolosine Projection, which is an equal areaprojection. All raster datasets had a cell size of 1000 meters (1km).

The data layers were analyzed individually or combined withother data layers in order to see possible interrelations or possi-ble spatial relationships among them. For example, “bufferlayer”, “population density layer” and “political boundarieslayer” were digitally overlaid in order to assess the populationpressure on the coastal zone by countries.

i) Population distribution: A buffer of 100 km around conti-nental boundaries (excluding Antarctica and inland lakes) de-fined the coastal zone. The buffer zone combined with the popu-lation grid data. The number of people was counted for thecoastal and inland areas. The resulting data were exported as aspreadsheet and combined in one graph showing the populationof the coastal zones and inland areas.

ii) Population density in the coastal zone: The following clas-sification was used for population density: Low population den-sity: < 25 people km–2; Medium population density: 25–100 peo-ple km–2; High population density: > 100 people km–2.

iii) Land cover distribution in coastal zones: The land coverdistribution in coastal zones by country was estimated by com-bining the political boundary grid, the 100 km buffer zone gridand the land cover distribution grid.

iv) Protection status of coastal zones: The protection statusof coastal zones was estimated by combining the protected areagrid with the 100 km buffer zone and political boundary grids.

v) Biodiversity hotspots in coastal zones: The presence ofbiodiversity hotspots in coastal zones was estimated by combin-ing the hotspots grid with the 100 km buffer zone and politicalboundary grids.

vi) Projection of population in coastal zones: Preliminary pro-jection numbers of population and population pressure in thecoastal zone are given separately for 2000, 2010, 2025, and 2050.The percentage of population in the coastal zone by country in1990 was multiplied by the projected total population in orderto project the population in the coastal zone for 2000, 2010,2025, and 2050. A linear population growth rate is projected for

crowded and overexploited (16). The global population has in-creased from 2.5 thousand million to 6.1 thousand million in thelast 50 years (17, 18). In many parts of the world coastal zonesare considered to be the fastest population growth areas (6). Glo-bal climate change may compound other pressures on coastalzones through the additional effects of warmer ocean tempera-tures, altered ocean circulation patterns changing storm fre-quency, and rising sea levels (19). Rising sea level, associatedwith climate change, is likely to affect virtually all of the world’scoasts. During the past century, sea level has risen at a rate of1.0–2.5 mm yr–1 (20). The Intergovernmental Panel on ClimateChange (IPCC) has projected that global sea level will rise 15–95 cm by 2100, due principally to thermal expansion of the oceanand the melting of small mountain glaciers (20). Future envi-ronmental changes are likely to affect the global coastal zonemore than other inhabited regions of the world.

The question is how many people now live in coastal zonesand what is their distribution? Many different estimates havebeen presented (Table 1). The United Nations in1992 estimatedthat more than half the world’s population lived within 60 kmof a shoreline, and this could rise to about 60% by the year 2020(7). Hinrichsen in 1995 estimated that about 54% of Americanslived in 772 coastal counties (16); the United Nations Associa-tion in Canada in 1991, calculated that 7 out of 10 people in theworld lived within 80 km of a coast and almost half of theworld’s cities with populations of over one million people weresituated around estuaries (4); Vitousek et al. in 1997 estimatedthat 60% of Americans lived within 100 km of coastal zones(21); The World Resources Institute in 2000 estimated that 40%of the world’s population lived in coastal zones (22): NOAA in2000 re-estimating from 1998 data that 53% of Americans livedon 17% of the coastal land area (23). In addition, the Commit-tee for the National Institute for the Environment in 1998 (24),NOAA in 1998 (25), Watson et al. in 1997 (26), and Cohen etal. in 1997 (27) attempted to provide an estimation of humanpopulations living in coastal zones. In most of these compila-tions, disparities in the relative study methods and study perspec-tives are of serious concern. There is no reliable estimate of howmany people live in the global coastal zones using consistent datasources and methodology. Hence, a reliable estimation of popu-lation distribution in coastal zones is needed to reduce uncer-tainly in the various estimations. (Table 1).

Based on this analysis we estimate that coastal zones whichextend from the coastline to 100 km inland, occupy approxi-mately 19.2% of the land area (the Antarctic continent excluded)in the world. The comparison of population pressure on coastaland total land area is given in Table 2.

Population density is higher in coastal zones than inland, withan average of 87 people km–2 in coastal zones compared to 23people km–2 inland in 2000. In regard to population distributionin coastal zones, 63.7% of the area has low or nonexistent popu-lation density, 19.2% has medium population density, and theremaining 17.1% is under high population pressure (Fig. 1). The

Table 2. Comparison of population density in coastal zone and total land area1.

% of Low PD2 % of Medium PD % of High PDContinent Coast Total Coast Total Coast Total

Africa 65.85 83.88 23.31 11.97 10.84 4.15Australia and Pacific 73.80 88.81 13.19 6.14 13.02 5.05Europe and Asia 46.77 64.21 22.34 18.18 30.89 17.60North America 82.47 87.11 10.74 8.90 6.79 3.99South America 59.34 83.24 32.54 13.67 8.12 3.09World 63.67 76.97 19.22 13.65 17.12 9.38

1. 1990 Data;2. Population Density, Low PD: < 25 people km–2, Medium PD: 25–100 people km–2,

High PD: > 100 people km–2.

every country’s coastal zone.vii) Distribution of the world’s cities in the

coastal zone: A grid of cities with more than100 000 people was combined with the bufferlayer in order to obtain the number of cities thatare located in 100 km of the coastal zones.

HOW CROWDED ARE COASTALZONES?It has long been understood that a considerableportion of coastal zones, suitable for humanhabitation, are among the most crowded and de-veloped regions in the world. Throughout muchof the world, coasts are overdeveloped, over-

148 © Royal Swedish Academy of Sciences 2003 Ambio Vol. 32 No. 2, March 2003http://www.ambio.kva.se

High > 100 people km–2

Medium 25–100 people km–2

Low < 100 people km–2

highest population pressures exist in coastal zones in Europe andAsia, with 31% of the area having high population density.

About 2 thousand million people or 38% of the world’s totalpopulation, live within the narrow coastal fringe of the world.However, more than 60% of the world‘s coastal zones are cov-ered by snow, ice, desert, closed forests, and wetlands, and arenot suitable for permanent habitation. Thus, most of the 2 thou-sand million coastal inhabitants live in less than 40% of theworld’s coastal zones, creating high population density in thoseregions. About 38% of the world’s population lives on 7.6% ofthe total land area on earth.

We selected and analyzed 10 countries by total population incoastal zones (Table 3). In China, India, Japan, Bangladesh, thePhilippines, Vietnam, and the United Kingdom over 50% of theland with high population density was in the coastal zone. China,Bangladesh, and India have very high population concentrationsin the coastal zones, with 93%, 89%, and 86%, respectively.Population pressure in coastal areas of Canada, Australia, andRussia are very low because most coastal zones in these coun-tries are located in the polar or desert regions and are unsuit-able for human habitation, or the total population is low to be-gin with. Australia is a special case, with 84% of the popula-tion living in the coastal zone that occupies roughly 20% of thetotal land area, and still population pressure is relatively low.

In some island countries such as Japan, the United Kingdomand the Philippines, coastal zones cover most of the land area,and contain most of the population.

More than 260 cities with populations over 100 000 are lo-cated in coastal zones around the world, i.e. 50% of all citiesover 100 000 people. Eight of the top 10 most populous citiesin the world are located in coastal zones (Table 4). Among the10 most populous cities in the coastal zone, 5 are in Asia, 3 inSouth America, 1 in North America, and 1 in Europe.

The average population density in coastal zones was 77 peo-ple km–2 in 1990 and 87 people km–2 in 2000 (Fig. 2). We pro-jected population density for the future using current data, as-

suming similar population growth rate as for the entire countries.In 2010, 2025, and 2050, population density will increase to 99people km–2, 115 people km–2 and 134 people km–2, respectively.Population density in coastal zones will be much higher than ininland areas, which is expected to be 38 people km–2 in 2010,44 people km–2 in 2025 and 52 people km–2 in 2050. Thus,coastal zones constitute “bright spots” for current and futurepopulation distribution and growth in the world.

DISTRIBUTION AND PATTERN OF LAND COVER INCOASTAL ZONESNatural land resources are threatened by uncontrolled degrada-tion and conversion to alternative land uses, including agricul-tural expansion and urbanization. The impacts of loss and deg-radation are obvious from biodiversity depletion, soil erosion,wetland loss in coastal zones, and decreased options for devel-opment.

The coastal zones’ diverse and productive habitats are impor-tant for human settlements, development, and local subsistence.Coastal resources are vital for local communities and indigenouspeople. Despite efforts at varying levels, current approaches to

Table 4. The 10 most populous cities in coastal zones of theworld (people, million).

City Population Country Continent World Rank

Tokyo 23.62 Japan Asia 1New York 16.47 US North America 2Seoul 15.85 Korea Rep Asia 3Sao Paulo 15.18 Brazil South America 4Osaka 15.04 Japan Asia 5Calcutta 11.10 India Asia 8London 11.10 UK Europe 9Buenos Aires 10.75 Argentina South America 10Rio de Janeiro 10.15 Brazil South America 11Bombay 9.95 India Asia 12

Table 3. Population distribution and pressure in top 10 countries1.

Population Land area % Population PD2 of coast(million people) (thousand km2) pressure zone

Country Total % in CZ3 Total % in CZ Low Medium High (People km–2)

China 1156.39 25.02 9402.35 6.06 1.20 6.19 92.61 507India 850.79 27.53 3154.40 16.71 4.66 9.75 85.59 444Indonesia 182.81 93.27 1887.48 69.06 52.41 26.74 20.84 131Japan 123.54 96.08 367.23 94.02 4.71 24.25 71.03 344United States 254.11 39.19 9406.27 16.99 71.63 15.65 12.72 62Bangladesh 109.77 76.61 135.64 67.01 3.29 8.13 88.58 925Philippines 60.78 100.00 288.75 94.12 5.89 26.68 67.43 224Vietnam 66.69 89.86 326.17 57.37 16.18 25.78 58.04 320United Kingdom 57.56 94.26 237.38 96.06 17.16 25.56 57.27 238Brazil 148.00 34.31 8500.63 9.16 47.04 40.12 12.85 65World 5368.22 37.97 134 388.57 19.18 63.67 19.22 17.12 79

1. Selected by the total population of coastal zones; 2. Population density; 3. Coastal Zone.

Figure 1. Population densityin global coastal zones.

149Ambio Vol. 32 No. 2, March 2003 © Royal Swedish Academy of Sciences 2003http://www.ambio.kva.se

Closed forests (density > 40%)Open or fragmented forests (density 10–40%)Other wooded landsBarren, snow, and iceGrasslandCultivationWater

67

141

44

7769

79

155

50

8789 90

171

32

57

99

123

37

67

173

123

211

41

77

134

26 29

191

104115

0

50

100

150

200

250

Africa Australia andPacific

Europe andAsia

North America South America World

1990 2000 2010 2025 2050

the management of coastal resources have not always provedcapable of achieving sustainable development, and coastal re-sources and environments are being rapidly degraded and eroded.However, coastal management, where successful, has brought acertain measure of order and predictability to the process of con-temporary anthropogenic change.

Conservation and restoration of coastal ecosystems has beenachieved in only a few instances. The goal of sustainable formsof coastal development lie a long way off. It is increasingly vi-tal that coastal states conduct regular assessments of the stateof their coastal zones and marine areas (28). Rapidly, develop-ing countries, often base their economic success on the exportof labor-intensive manufactured goods. Large export activitiesrequire access to coastal zones. Almost all countries with eco-nomic success in the export of labor-intensive goods havepopulations, almost entirely, within 100 km of the coast (29).Coastal regions and those near navigable waterways are indeedfar richer and more densely settled than interior regions, just asthe Scottish economist Adam Smith, (The Wealth of Nations,1776) predicted. A map of the global distribution of economicoutput indicated by GNP—the product of population density andgross national product per capita shows that output is concen-trated along the seacoasts and navigable waterways of theworld’s temperate zones (2). Thus, coastal zones are destinedto be developed even further and concern for the sustainabilityof these areas is imperative. In order to develop a suitable strat-egy for sustainable development of coastal zones, it is vital toassess the distribution and pattern of land cover and its protectedstatus.

As mentioned earlier, coastal zones are estimated to occupyabout 19.2% of land area of the world (Fig. 3). Land cover dis-tribution in coastal zones derived from remote sensing data, isas follows: 21.8% closed forest (density > 40%), 12.1% openor fragmented forests (density 10–40%), 7.8% other wooded

land, 37.2% barren, snow and ice, 4.3% grassland, 14.8% culti-vation (include urban) and 1.9% water.

In Figure 3, land cover patterns in coastal zones are shown.Several broad forested areas can be seen in North America,northwestern Europe, tropical South America, eastern Asia, east-ern Australia, and tropical western Africa. Barren/ice/and snowcover exist in the coastal zones of the Arctic region, westernAustralia, the Middle East, and the west coast of Saharan Af-rica. Cultivated land is primarily located in coastal zones of tem-perate and subtropical climate regions.

The area under closed forest cover was estimated at 10.5%,32.3%, 20.5, 23.7%, and 20.9% in Africa, Australia and Pacific,Europe and Asia, North America and South America, respec-tively; North America and Africa have the largest percentage ofland that is barren, or snow and ice covered, 54.6% and 44.8%;Europe and Asia have the highest percent under cultivation andin inland lakes, 23% and 2.47%; Australia and Pacific have moreareas of grassland, 10.3% (Fig. 4).

Of the top 10 coastal zone countries of the world, (Table 5)Canada has the largest coastal area in the world, estimated at2.7% of the total global coastal zone area. Closed forests incoastal zones cover 45.13% of the coastal area in Indonesia and34.4 % in Mexico. China and India have most cultivated landin their coastal zones, 55.16% and 47.52%, respectively. Chilehas the most barren coastal area 50.42%; Canada and Russia,with large areas in polar regions, have the largest snow and icecovered coastal zones, 67.2 % and 56.8%, respectively.

STATUS OF DESIGNATED PROTECTED AREASAND BIODIVERSITY HOTSPOTS IN THE COASTALZONESBiodiversity, the variety and variability of living organisms andthe environment in which they occur, is important to maintainthe life-support systems of the biosphere (30). Many human ac-tivities are reducing biodiversity. The total number of speciesthat inhabit the planet is unknown, and it is feared that extinc-tion of species will occur even before they have been named anddescribed. It is estimated that 85–90% of all species can be savedby identifying and protecting areas of high biodiversity beforethey are further degraded, without having to actually inventoryspecies individually (26). Realistically, only a relatively smallportion of total coastal zone areas are likely to be earmarked forbiodiversity conservation; hence, it is important to identify ar-eas rich in species diversity and endemism for priority-settingpurposes. In the past, areas have been set aside as protected, of-ten without regard to the biodiversity within their boundaries,As a result, many protected areas have little significance in termsof biodiversity, and, conversely, many areas of habitat with sig-nificant biodiversity lack protection.

Figure 3. Land cover distributionin global coastal zones.

Figure 2. Population density trend in the coastal zones, by continent.People km–2.

150 © Royal Swedish Academy of Sciences 2003 Ambio Vol. 32 No. 2, March 2003http://www.ambio.kva.se

8.87

48.14

23.41

32.76

12.61

23.93

5.57

10.32

5.59

19.34

10.46

10.45

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Africa

Australia and Pacific

Europe and Asia

North America

South America

World

39.45

54.32

39.98

36.22

48.17

41.79

44.83

18.80

33.02

53.59

25.66

37.24

7.63

10.26

1.51

1.73

8.38

4.28

7.41

15.67

2.47

6.23

16.14

14.81

0.69

0.95

2.47

2.23

1.65

1.88

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Africa

Australia and Pacific

Europe and Asia

North America

South America

World

Forests Barren, snow and Ice Grassland Cultivation Water

The next 10 years could be called the “last chance decade.”(31). These could be some of the most dangerous years ever forthe earth’s species and ecosystems. Yet this is also a time inwhich we will still have a chance to make a difference. We arealready down to a relative handful of fragile places wherebiodiversity is still robust. These biodiversity “hotspots” are re-mote, they are spectacular—and, without exception, they are indanger of being destroyed. To protect the diversity of life onearth, we need to protect these invaluable hotspots (31). Manyareas in global coastal zones have very rich biodiversity. Man-groves and coral reefs are representative of the types of threat-ened biotopes in the global coastal zone. Approximately 8% ofthe world’s coastline (32) and about 25% of tropical coastlinesare mangroves, covering a surface area of approximately 181 000km2. Some 112 countries and territories have mangroves withintheir borders (33). It is estimated that already half of the world’smangrove forests have been destroyed (34).

Worldwide, an estimated 255 500 km2 of shallow coral reefsexist, with more than 90% in the Indo-Pacific region (35). Coralreef areas have also significantly declined in some parts of theworld (36).

In order to address the issue, this study assessed and analyzedthe status of protected areas and biodiversity hotspots in globalcoastal zones to address the question: Are areas in coastal zoneswith significant biodiversity adequately protected?

Designated protected areas cover roughly 10.45% of coastalzones (Fig. 5). About 12.7% closed forests, 7.9% open and frag-mented forests, 8.2 % other woodland, 10% barren, snow andice, 8.6% grassland, 2.1% cultivation, and 10% water have beendesignated as protected areas in global coastal zones. Forests,especially tropical forests are biologically the most diverse andhome to thousands of endemic species.

Worldwide about 40.7% of the area of biodiversity hotspotsis concentrated in the coastal zones. Continental distribution isas follows: 48.05% in Africa, 74.48% in Australia and the Pa-cific, 35.86% in Europe and Asia, 68.73% in North America,and 17.07% in South America (Fig. 6). As a percentage of allprotected areas in each continent, designated protection statusof hotspots ranks 12.4% in North America, 10.9% in Australiaand Pacific, 7.51% in Europe and Asia, 6.7% in South America,and 2.3% in Africa.

In Figure 7, the percentage of each hotspot that lies within thecoastal zone and its protection status is apparent. Of the 25 to-tal hotspots around the world, 23 of them are at least partiallywithin the global coastal zone, except the Brazilian Cerrado andthe mountains of South Central China. There are 9 hotspots thathave at least 90% of their area in the coastal zone, while only 3of them have below 30% of their area in coastal zones.

The lack of designated protected areas within the globalcoastal zones is alarming. On average, only 8.5% of hotspots inglobal coastal zones are designated as protected areas. Out ofthe 23 total hotspots in the global coastal zone, 21 of them areprotected at a level of 13.38% or less. The hotspots of Polynesia

and Micronesia have absolutely no area under designated pro-tected status. The hotspot with the largest area under protectionis the Tropical Andes with 32% being protected. The critical is-sue is to establish immediate protection status in areas which re-main unprotected (Fig. 7).

Of the 23 hotspots in coastal zones, 14 of them are at leastpartially located within borders of more than 58 countries (Ta-ble 6). The Caribbean and Mediterranean basin hotspots existwithin more than 15 countries and 12 countries, respectively (ex-cluding small island nations).

DISCUSSION AND CONCLUSIONSThe causes and consequences of human-induced environmentalchange are not evenly distributed over the earth. They converge

Table 5. Global coastal zones land cover distribution in top 10 countries1 (percentage).

Total Open and Barren, Designated Area underland Closed fragmented Other snow protected biodiversity

Country area forests forests woodland and Ice Grassland Cultivation Water area hotspots

Canada 34.83 19.05 5.58 4.67 67.17 0.02 0.60 2.91 10.89 0Russia 16.43 19.78 11.65 4.00 56.82 2.21 1.92 3.64 6.57 0.39United States 16.99 30.99 9.54 7.42 32.47 4.37 13.04 2.18 26.07 1.82Australia 20.39 16.02 11.92 17.65 28.33 14.16 11.39 0.53 8.40 2.23Indonesia 68.81 45.13 17.28 0.03 15.40 2.62 18.35 1.19 14.23 53.87Brazil 9.12 22.16 20.54 24.65 7.61 3.56 19.65 1.83 3.83 4.60Mexico 37.69 34.40 13.17 3.05 32.74 4.07 11.90 0.67 5.57 23.82China 6.03 19.44 14.56 2.93 4.38 1.19 55.16 2.34 2.20 0.86India 16.70 10.97 13.20 10.24 16.60 0.05 47.52 1.42 7.36 3.81Chile 64.81 13.03 10.21 6.90 50.42 10.27 6.91 2.26 16.36 30.08World 19.28 21.86 12.14 7.79 37.24 4.28 14.81 1.88 10.45 24.751. Selected by coastal zone area.

Figure 5. Percentage of protected areas in coastal zones, by continent(Green). Percentage of designated protected areas in the coastal zoneto the total area under coastal zones (Yellow). Percentage ofdesignated protected area in the coastal zones to the area designatedas protected for the continent.

Figure 4. The percentage distribution of land cover in the coastalzones, by continent.

151Ambio Vol. 32 No. 2, March 2003 © Royal Swedish Academy of Sciences 2003http://www.ambio.kva.se

47.71

89.67

99.78

20.63

76.79

91.83

39.3035.12

30.76

59.38

73.9567.91

0.00

91.27

99.5796.30

99.90

55.74

68.8968.01

6.93

88.98

68.10

40.74

1.580.00

28.28

1.088.797.014.28

11.152.813.70

9.051.651.84

9.27

0.001.68

11.203.380.00

11.36

2.11

11.34

32.15

13.3812.01

8.50

0.00

20.00

40.00

60.00

80.00

100.00

120.00

48.05

74.48

35.86

68.73

17.07

40.67

29.77

46.81

16.76

17.58

34.80

24.75

2.27

10.88

7.51

12.42

6.68

8.48

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00

Africa

Australia and Pacific

Europe and Asia

North America

South America

World

in certain regions and places where their impacts may threatenthe long-term or even the short-term sustainability of human-en-vironmental relationships (37). Geographic analyses of relation-ships between population distribution and growth, distributionof land cover types, protected areas, and biodiversity hotspotsin global coastal zones revealed that coastal zones have higherpopulation pressure compared to the inland areas of the world.Areas of population density > 25 people km–2 occupy approxi-mately 40% of the total global coastal zone. This is a remark-ably high density, especially considering that approximately 60%of the coastal zone is totally unsuitable for human habitation dueto conditions like snow, ice, wetland, and barren land. In otherwords, the entire portion of the global coastal zone, which is suit-able for human living, is subject to high population pressure. Thishigh population can severely degrade natural resources and af-fect the environmental sustainability of these regions. Currentestimates, using the latest demographic data on populationgrowth and distribution, indicate with certainty that populationsare increasing in coastal zones around the world, especially inAsia, Latin America, and Africa. In many areas of the develop-ing countries, growth rates are falling steadily (except in sub-Saharan Africa). But in terms of coastal demographics, the num-bers show a consistent pattern of growth over the last 30 years(16), and the coastal population is expected to double within thenext 30 years (24). Some studies and data (7, 38) show that thegreatest increases of population in most regions have been reg-istered in urban areas in coastal zones. This study projects thatbased on current trends, there will be a steady rise in popula-

Table 6. Percentage distribution of areas of transboundary hotspots in global coastal zones.

Biodiversity Hotspots Countries (%)Atlantic Forest Brazil (99.99), Uruguay (0.01)California Floristic Province Mexico (15.8), United States (84.2)Caribbean Bahamas, The (3.07), Cuba (43.48), Dominican Republic (19.38), Haiti (10.71), Jamaica (4.39), Puerto Rico (3.55),

United States (12.28), others (2.11)Central Chile Argentina (2.94), Chile (97.06)Choco-Darien-Western Ecuator Colombia (38.29), Ecuador (33.27), Panama (13.67), Peru (14.77)Eastern Arc Mountains and Coastal Kenya (8.61), Tanzania (91.39)Forest of Tanzania and KenyaGuinean Forests of West Africa Benin (1.94), Cameroon (8.54), Cote d’Ivoire (Ivory Coast) (17.16), Ghana (14.77), Guinea (3.50), Liberia (15.97),

Nigeria (24.92), Sierra Leone (10.77), Togo (2.43)Indo-Burma Bangladesh (2.67), Cambodia (6.33), China (11.55), India (1.70), Laos (4.06), Myanmar (Burma) (27.53), Thailand

(19.15), Vietnam (26.74), Malaysia (0.27)Mediterranean Basin Algeria (4.82), Cyprus (2.30), France (3.72), Greece (11.54), Israel (2.29), Italy (13.82), Lebanon (2.61), Libya (4.00),

Morocco (10.82), Spain (16.88), Turkey (26.26), Syria (0.91), Others (0.02)Mesoamerica Belize (2.81), Costa Rica (6.49), El Salvador (2.59), Guatemala (6.09), Honduras (9.61), Mexico (56.47), Nicaragua

(10.24), Panama (5.71)Succulent Karoo Namibia (21.27), South Africa (78.73)Sundaland Indonesia (73.16), Malaysia (25.09), Thailand (1.18), Brunei (0.58)Tropical Andes Chile (4.08), Colombia (22.97), Ecuador (17.89), Peru (24.49), Venezuela (30.56)Western Ghats & Sri Lanka India (62.44), Sri Lanka (37.56)

tion numbers and density in coastal zones over thenext 50 years. In most cases, these increases aredue to in-migration from the countryside, not natu-ral population growth. Hence, policy-makers andgovernment officials should concentrate their ef-forts towards mitigating the migration towardscoastal areas.

High population growth in and around naturalforests, wetlands, and coral reefs, all of which havehigh biodiversity, is a threat to coastal ecosystems.These coastal ecosystems are vital for the survivalof local populations. Most coastal ecosystems arelikely to be irreparably damaged if a conventionaldevelopment path, characterized by the over-exploitation of natural resources for economicgrowth, is followed.

Eight of the top 10 most populous cities in theworld are located in the coastal zones. Rapid ur-banization processes have been contributing to aseries of coastal environmental issues, such as landdegradation, freshwater shortage, biodiversity loss,and pollution.

The location of a majority of the world’s largest

Figure 7. Percentage of each hotspot and its protection status that lies within thecoastal zones. (Yellow) Percent of area of each hotspot within the coastal zone. (Red)Percent of total hotspots protected within the coastal zone to total area of the coastalzones.

Figure 6. Percentage distribution of area of biodiversity hotspots incoastal zones, by continent. (Dark green) Percentage of area ofhotspots in coastal zones to total area under continental hotspots.(Yellow) Percentage of hotspots designated as protected to total areaof the coastal zones area. (Green) Percentage of protected hotspots incoastal zones.

cities and high population density areas in coastal zones makethem increasingly vulnerable due to environmental changes suchas sea level rise, natural hazards such as cyclones, flood and tsu-namis. Appropriate policy measures are urgently needed to avoidfuture catastrophes.

Only 10.45% of coastal zones are designated as protected ar-eas. The most valuable mangrove forests, wetlands, and coral

152 © Royal Swedish Academy of Sciences 2003 Ambio Vol. 32 No. 2, March 2003http://www.ambio.kva.se

Hua Shi is currently working with the United NationsEnvironment Programme Global Resource InformationDatabase (UNEP/GRID) - Sioux Falls as scientist from theChinese Academy of Sciences. He has been engaged in thesurvey and research of natural resources, environment aswell as regional ecology for many years. His researchconcentrates on the assessment of land covercharacterizations, analysis of environmental change, andpopulation-environment dynamics. His address: UNEP/GRID, Division of Early Warning and Assessment – NorthAmerica USGS/EROS Data Center, 47914 252nd Street,Sioux Falls, SD 57198 USA.E-mail: hua@usgs.gov

Ashbindu Singh joined UNEP/GRID in Bangkok in 1990, andlater transferred to UNEP Headquarters in Nairobi. He iscurrently Regional Coordinator of UNEP Division of EarlyWarning and Assessment—North America. He is an experton issues related to global environmental data, information,assessment and monitoring and is regularly consulted andinvited by various scientific institutions to deliver lecturesaround the world. His address: UNEP/GRID, Division ofEarly Warning and Assessment – North America USGS/EROS Data Center, 47914 252nd Street, Sioux Falls,SD 57198 USA.E-mail: singh@usgs.gov

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reefs within the biodiversity-rich coastal zones lack adequate pro-tection. Accordingly, practical action programs that establish anetwork of protected areas should be given high priority.

A shift in national and international policy and planning proc-esses, based on targeting biodiversity-rich areas, is needed to pro-tect biodiversity more effectively. Geographic targeting and pro-gram focus are both needed to conserve ecoregions rich inbiodiversity, and to address the socioeconomic causes of en-croachment and subsequent loss of biodiversity.

Conservation International identified 23 out of 25 biodiversityhotspots located within the coastal zones. Only 8.5% of hotspotsin the coastal zones have been granted protected status, and mostof these cross political borders. The conservation and manage-ment of these biologically diverse hotspots deserves greater at-tention. They are located on multiple boundaries and adminis-tered under different and potentially conflicting policies. Onlynational authorities can take action for the preservation ofhotspots under their jurisdiction, but transboundary conservationrequires cooperation between different nations, regions, and in-ternational organizations. In the interest of developing an effec-tive collaborative management system for hotspots with multi-

national jurisdiction, it is imperative that the contradictions inapproach and conflicts of interest are harmonized. Without ne-gotiation, joint management, and enforcement strategies, suchharmony will be difficult to attain. The absence of joint man-agement mechanisms may also become a hurdle to enforcing in-ternational conventions.

There are considerable differences in statistics between thisstudy and others done in the past in regard to data on popula-tion density, land cover distribution, protected areas, and bio-logically diverse hotspots. These differences highlight the needto provide more resources for improving the environmental in-formation infrastructure. Such initiatives are necessary to gen-erate and maintain accurate and up-to-date environmental datafor planning policy formulation.

There is an urgent need to assess and regularly monitor theprocess of change in coastal areas. The data presented here pro-vide a baseline for important variables in coastal regions at theglobal scale. Regular use of high resolution satellite data suchas those from Landsat could be integrated with in situ data todevelop an internally coherent monitoring system to provide in-formation for decision making.

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39. Acknowledgements and disclaimers: Financial support by UNEP, NASA and USGSare acknowledged. We are grateful to UNEP-WCMC, Conservation International andWRI for providing some of the datasets. Also we appreciate Mr. R. Reker, Mr. M.Ernste, and Ms. K. Giese for their assistance. Thanks to Dr. E.A. Forsnight, Dr. T.R.Loveland, Dr. Z. Zhu. Dr. N.B. Bliss, Mr. E. Waller, S. Olsen, and Ms. P. Shamsieva-Cohen, for their valuable comments and contributions. The views express in this studyare not necessarily those of the UNEP or cooperating agencies. The designations em-ployed and the presentations do not imply the expression of any opinion whatsoeveron the part of the cooperating agencies concerning the legal status of any country, ter-ritory, city, or area or of its authorities, or of the delineation of its frontiers or bounda-ries.

40. First submitted 30 April 2001. Accepted for publication after revision 15 Febr. 2002.