Coral Diseases

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i

Supervised by: Sally Lim & Ian Baker

Muhammad Erdi Lazuardi

2nd

project of Deep 2, English language course

2012

CORAL DISEASES



ii

CORAL DISEASES

2nd

project of Deep 2, English language course

James Cook University – Pathway College

Written by:


All cover pictures by:


Supervised by:

Sally Lim

Ian Baker

January, 2012



iii

Contents

1. Introduction ......................................................................................2

1.1 Background ................................................................................................................. 2

1.2 Objectives .................................................................................................................... 3

2. Coral diseases ...................................................................................4

2.1 What is disease? .......................................................................................................... 4

2.2 The description of coral lesions in the field ................................................................ 5

2.2.1 Known causes of lesions by animals and the environment.................................. 6

2.2.2 Lesion type of diseases ........................................................................................ 8

2.2.2.1 Tissue loss..................................................................................................... 8

2.2.2.2 Growth anomalies ....................................................................................... 10

2.2.2.3 Tissue discoloration .................................................................................... 10

3. Monitoring coral diseases ..............................................................11

4. How to deal with coral diseases based on scientific research .......12

5. Conclusion .....................................................................................14

Acknowledgements .............................................................................15

References ...........................................................................................16



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Figures

Figure 1. Map of coral reefs worldwide. .................................................................................... 2

Figure 2. A decision tree identifying coral lesions based on visual identification in the field. . 5

Figure 3. Fish bites on massive coral ( Porites sp.). ................................................................... 6

Figure 4. Drupella gastropods bite on branching coral ( Acropora sp.). .................................... 6

Figure 5. Tube formers living inside coral................................................................................. 7

Figure 6. Algae grows rapidly on a wide coral’s colony. .......................................................... 7

Figure 7. Crown of Thorn predation on coral. Photo: author .................................................... 7

Figure 8. Sedimentation on coral. Photo: author. ...................................................................... 8

Figure 9. a. Black-band disease on massive coral; b. White-band disease on stag-horn coral;

c. Red-band disease on gorgonian. ............................................................................. 8

Figure 10. Red-band disease on massive coral (Faviidae). ........................................................ 9

Figure 11. Growth anomaly on massive coral ( Porites sp.). ................................................... 10

Figure 12. a. Tissue discoloration on massive coral ( Montipora sp.). b. Tissue discoloration

on sub-massive coral (Goniopora sp.). Possibly causes by thermal bleaching.

Photo: author. .......................................................................................................... 10

Figure 13. Coral disease monitoring activities. Photo: author. ................................................ 11

Figure 14. White pox disease on Acropora palmata in Caribbean reefs. ................................ 12

http://d/JCU%20English%20Course/project%202%20-%20coral%20diseases.docx%23_Toc315686695

































































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Coral Diseases

1. Introduction

1.1 Background

Many scientists say coral reefs are comparable to tropical rainforests underwater due to

their abundance of species and great ecological complexity. They are like an oasis in the

middle of the desert due to the primary energy they produce, and the benefits they provide for

other creatures living around them as well as for humankind.

Coral reefs are typical of the tropical ecosystem. Nybakken (1988) says coral reefs are

massive deposits of calcium carbonate mainly from coral, the organisms of phylum Cnidaria,

class Anthozoa and the order of Scleractinia, and other marine organisms also contribute to

the creation of the reefs that produce calcium material.

Corals themselves are a kind of invertebrate animal. Mainly, they live in tropical waters

due to the sunlight and warm sea temperature stability they need. They need sunlight and

stable temperatures due to algae (named Zooxanthellae) that live inside their body as

symbiosis mutualism. Zooxanthellae needs photosynthesis to produce nutrition and contribute

to coral’s nutrition, while coral provides a

haven for zooxanthellae.

Coral is classified a “hard coral” or “soft

coral” related to the calcareous skeleton they

build. The majority of coral grows in

colonies, creates life-form structures such as

massive, sub-massive, branching, tabulate, digit like (digitate), and encrusting. Some species

of corals have solitaire forms, mainly as ‘mushroom’ life-form.

Figure 1. Map of coral reefs worldwide.



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Coral Diseases

There are many benefits of coral reefs. Firstly, in terms of physical benefits, coral reefs

could prevent erosion of coastal area from waves. Secondly, biological benefits are that they

provide feeding and nursery grounds, and habitats to other organisms such as fish, crustacean

and mollusc. Thirdly, as far as economic benefits are also are concerned, coral reefs provide

economic resources such as fish and medicines’ substances. Fourthly, there are also esthetic

benefits as coral reefs provide picturesque scenery and enable for marine tourism.

However, despite their importance, reefs are still negatively affected by what Raymundo,

Couch & Harvell (2008) refer to as “the big four” human activities that threaten their

sustainability: climate change, land-and marine-based pollution, habitat degradation, and

over-fishing. They also state:

“One phenomenon which has recently gained the attention of coral reef

scientists and managers is disease. Diseases affecting corals have

increased in both frequency and severity within the last three decades and

caused major community shifts on reefs. Yet we are only beginning to

understand enough about drivers of disease outbreaks to consider

management actions”.

1.2 Objectives

This report was written for students and coral reef observers, governments, managers and

stakeholders of marine protected areas who are interested in coral diseases. This article

explains what is currently known about coral reefs diseases, identification and causes, and

furthermore states about coral diseases monitoring. It also provides solutions for how to deal

with coral diseases based on scientific research.



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Coral Diseases

2. Coral diseases

Regarding the words ‘coral diseases’, normally, scientists clarify coral diseases in terms

of the diseases that infect the colony of hard corals. Although the diseases also infect some

organisms such as Gorgonian (sea fan) and soft coral on coral reefs, most diseases are found

on hard coral.

2.1 What is disease?

Raymundo et al. (2008) use the terms disease to mean “any impairment to health

resulting in physiological dysfunction”. They also say disease engages a relation between a

host, an agent, and the environment.

There are several diseases in coral reefs as Raymundo et al. (2008) mention. First,

infectious biotic diseases, caused by a microbial agent, for example bacterium, fungus or

virus, broadened between host organisms and harmfully affect the host’s health. Second,

abiotic diseases; they do not associate a microbial agent but weaken health. Possibly, those

caused straightforwardly by sedimentation, stress, temperature, toxic chemicals, nutrient

disparity and UV radiation, as environmental agents. Lastly, noninfectious biotic diseases;

they does not spread among organisms, although they may be effected by a microbial agent.

Thus, it is not effected by microbial directly, but a toxin taken out from microbes destroys the

host.

In a simple way, disease is a lack of health normally shown by the emergence of an

injury (a morphologic deformity). Raymundo et al. (2008) mention injury as “lesion”.



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Coral Diseases

2.2 The description of coral lesions in the field

This aim in this section is not to divide diseases based on causes, because more

information is needed from laboratory observations, but to divide coral diseases based on

visual coral lesions and early assessment.

According to Raymundo et al. (2008), there is a “decision tree” designed for “field-based

assessment of diseases” describing coral lesions and relevant to wide reefs.

One of the most important things is coral identification. Besides the ability to dive,

observers must have the ability in coral identification. It is a visual identification in coral

genus as well as species if possible.

Figure 2. A decision tree identifying coral lesions based on visual identification in the field.

3b. Yes record:

1. Lesions present 2. Host affected 3. Scene investigation:

known cause?

3a. No record:4. Lesion type

Tissue loss

Growth anomaly

Tissue discoloration

/ overlying

pigmented material

Fish bites/ skeletal damage

Gastropod bites

Galls, tube formers

Algal abrasion/ overgrowth

Crown of thorn predation

Sediment damage



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Coral Diseases

Figure 4. Drupella gastropods biteon branching coral

( Acropora sp.).

2.2.1 Known causes of lesions by animals and the environment

Visually, coral damaged by fish bites, gastropod bites, tube formers, algal abrasion,

crown of thorn predation and sediment damage have different appearances compared to coral

lesion with loss of tissue, growth anomalies, tissue discoloration, and overlying pigmentation.

Some pictures below are examples of the causes above.

White scars on the picture on the left are caused by fish

bites. In this case, the bites come from parrotfish

(Scaridae). These are not just coral tissue are lost, but

the skeleton is affected (corallite) as well.

White spots on the picture on the left are caused by

Drupella sp., a small gastropod that usually lives as a

parasite in branching coral of Acropora sp. The bigger

problem is when Drupella outbreaks happened. They

could exterminate coral colonies.

Figure 3. Fish bites on massive

coral ( Porites sp.).

Photo: author



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Coral Diseases

Figure 5. Tube formers living

inside coral.

Photo: author.

Figure 6. Algae grows rapidly on

a wide coral’s colony.

White spots on the picture on the left are caused by tube

formers that live from inside coral to the coral’s surface.

Although it is harmful, coral colony could continue

survive.

Algae grows rapidly covering a wide coral’s colony. This

happens when sedimentation or run off from land enters

the waters more than usual. Thus, corals could suffer from

these competing algae.

The branching coral’s colony seems to be bleached caused

by Crown of Thorns starfish (COT/ Acantharter planci)

predation. There are not only coral tissues that are lost,

but all coral polyps leaving only dead coral with clean

white corallite. COTs could be more dangerous when

outbreaks of their population. They could destroy colony

of corals in a huge area.

Figure 7. Crown of Thorn

predation on coral.

Photo: author



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Coral Diseases

Figure 9. a. Black-band disease on massive coral; b. White-band disease on stag-horn coral;

c. Red-band disease on gorgonian.

Sedimentation prevents coral from breathing properly

because their polyps are covered by sedimentation.

Moreover, sedimentation blocks the sunlight so that

zooxanthellae could not perform photosynthesis. As a

result, the coral becoming stressed and releases mucus

until coral dies, if sedimentation continues.

Figures 3 – 8 describe known causes from other animals and the environment. The

affect could be local such as fish and Drupella bites, but the other could be wider such as

crown of thorn predation and sedimentation.

2.2.2 Lesion type of diseases

2.2.2.1 Tissue loss

Tissue is a collective of cells in an organism that contains related structure and function

(biology-online.org, 2008). In terms of coral, tissue is a structure that covers the corallite

(coral skeleton) consisting of a body and tentacles to what we call a polyp. When disease

attaches, it causes loss of tissue and leaves only the corallite.

Some pictures below show diseases with tissue loss.

Figure 8. Sedimentation on coral.

Photo: author.

b ca



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Coral Diseases

Black-band disease is distinguished by a black line or crescent-formed band, dividing

healthy tissue and white dead coral. The disease is largely caused by a cyanobacteria

combining with sulfide-oxidizing bacteria and sulfur-reducing bacteria. Black-band disease

was discovered for the first time on the reefs of Belize and Florida in 1972 (coris.noaa.gov,

2010).

The cause of white-band disease is unidentified so far. Although strange microbe is

founded, scientists still could not identify this microorganism (coris.noaa.gov, 2010). White-

band disease appearance is similar with black-band disease except the color, which is white.

It is also separates healthy tissue and white dead coral. Normally it appears in coral branching

of Acropora sp.

Red-band disease is characterized by a red line separating healthy tissue and dead loss

tissue. As in figure 9.c., it happens not only on hard coral, but gorgonian as well. It appears

by a slender band of filamentous cyanobacteria moving slowly across the coral surface as

well as executing living tissue (coris.noaa.gov, 2010).

The picture on the left shows different types of red-

band disease in the filaments of cyanobacteria which

stretch round in a net-like manner leaving dead coral in

the middle.

Figure 10. Red-band disease on

massive coral

(Faviidae).

Photo: author.



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Coral Diseases

Figure 11. Growth anomaly on

massive coral ( Porites

sp.).

2.2.2.2 Growth anomalies

As in the introduction, corals mostly grow as massive, sub-massive, branching,

tabulate, digit-like (digitate), and encrusting forms colony. In reefs, sometimes we find an

abnormal growth in a normal coral colony life-form. The abnormality could have bigger or

smaller skeletal components. The cause and the dangers

are unknown. On the other hand, corallite could be

totally missing, and the growth anomaly leaves a white

plaque over the surface of coral colony (Raymundo et al.

2008).

2.2.2.3 Tissue discoloration

Tissue discoloration is the change of colour in the coral colony with colours such as

pink, purple and pale. It is considered to be a reaction of the coral to various stressors such as

coral life-competition, boring fauna, thermal bleaching, and abrasion from algae. (Raymundo

et al. 2008).

Figure 12. a. Tissue discoloration on massive coral ( Montipora sp.).

b. Tissue discoloration on sub-massive coral (Goniopora

sp.). Possibly causes by thermal bleaching. Photo: author.

a b



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3. Monitoring coral diseases

It is unavoidable that coral disease is a phenomenon that threatens the existence of reefs.

Monitoring of coral disease is needed to record changes over time in the same reef area. It

also could compare between other reef areas, locally, regionally or even globally. Moreover,

it could provide information about the trend of coral disease coverage in certain areas for

governments, managers and stakeholders of marine protected areas.

Therefore, a protocol to respond to coral disease monitoring should be designed. The

design of the protocol should be applicable to reefs worldwide, but also to answers what local

or regions specifically needs due to different types of diseases, coral hosts and characteristics

of each reef area.

Today, a coral disease handbook is

available to support effective

management of reef areas. Developed by

Coral Reef Targeted Research &

Capacity Building for Management, the

information about coral diseases and how

to monitor is fairly complete. Although

some new diseases on coral have been

found, the handbook is relatively relevant

to observers or managers of marine

protected areas.

Figure 13. Coral disease monitoring activities.

Photo: author.



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4. How to deal with coral diseases based on scientific research

The sea water provides microbial diversity. It remains unknown how many of these are

pathogens or prospectively so. Moreover, microbial diversity is not just supported by sea

water but linked to what happens on land. In addition, imperfect knowledge of coral, their

diseases and the factors that influence coral health, their resistance and their resilience are our

challenges in developing effective management (Raymundo et al., 2008).

Some evidence of threats to coral damage are known. For examples, outbreaks of crown

of thorns are caused by the extinction of their natural predator and nutrient run-off increased

by human use of coastal areas. Moreover, fast growing development of coastal areas brings

sediment into the reefs. (www.reef.crc.org.au, n.d). These cause coral damage and so coral

dies in huge areas.

In fact, microbial pathogens, cause coral

diseases such as white pox disease on stag-horn

coral ( Acropora palmata) in the Caribbean’s

reefs, known to have been caused from human

sewage (Sutherland & Ritchie, 2006). It seems

that most evidence of coral disease is linked to

human activities. Thus, governments,

managers and stakeholders of reef areas should

pay more attention to prevent the spread of coral diseases.

One solution is to link spatial planning from ridge to reef. Governments should

determine that coastal developments do not result in sediment to the sea. Moreover,

governments should create good management of human anthropogenic sewage to not be

released straight into the sea.

Figure 14. White pox disease on Acropora

palmata in Caribbean reefs.



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The other solution is to create as many reefs or marine protected areas as possible to

preserve coral reefs areas and take the benefits of them sustainably. Additionally,

governments or managers of marine protected areas could work together to prevents threats

to coral reefs.

Finally, all stakeholders must be involved in management of marine protected areas,

especially local communities who take benefits directly from their reefs.



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5. Conclusion

Coral disease is a phenomenon that threatens the existence of reefs today. There are at

least three kind of diseases based on causes in coral lesion: infectious biotic disease, abiotic

disease, and noninfectious biotic disease. On the other hand, there are some lesions and

damage to corals caused by other animals such as parrotfish and environmental aspects such

as sedimentation and changes of sea temperature.

Coral disease monitoring is to record changes over time in the same reef area as well as a

tool to compare between other reef areas, locally, regionally or globally. It is important to

give this information to governments, managers and stakeholders of marine protected areas as

an input in management of reef area.

Finally, incomplete knowledge of coral, coral diseases and the factors that influence

coral’s health, their resistance and their resilience are our challenges in developing effective

management of reef areas.



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Acknowledgements

Praise to Allah almighty.

I have been indebted in the preparation of this report to my teacher, my supervisor, Sally

Lim and Ian Baker of James Cook University – Pathway College, who have been improving

my English as well as my academic writing with their patience and kindness. I am very

grateful to all of JCU-Pathway College staffs who really helpful and nice. Everything is so

well-organized here.

To Dr. Agni Boedhihartono and Prof. Jeffrey Sayer, who encouraged me to continue

study in James Cook University. It is an 8 year of waiting, and in one more step I am going to

be a student of James Cook University, Australia. Thus, it is an honour.

I am very gratefully thanks to my parents, my brother and my sisters, who have been

providing thoughtful supports.

To Ditta, my wife and Aldebaran my son who always accompany, you are my joy, my

happiness, my reasons, my life.

And in the end the love you take is equal to the love you make (The Beatles).



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References

Algae overgrowth [image]. (2006). Retrieved January 25, 2012 from

http://www.coralmorphologic.com

Biology online. (2008). Dictionary. Retrieved January 2, 2012 from

http://www.biology-online.org/dictionary/Tissue

Black-band disease [image]. (2010). Retrieved January 25, 2012, from

http://coris.noaa.gov/about/diseases/

Coral Reef Map [image]. (2008). Retrieved January 20, 2012 from

http://www.coralreefinfo.com

Growth anomalies [image]. (2005). Retrieved January 26, 2012 from

http://archives.starbulletin.com/2005/12/25/news/story03.html

Nybakken, J.W. (1988). Marine biology: An ecological approach (M. Eidman, Ed.). Jakarta:

PT. Gramedia.

Raymundo, L.J., Couch, C.S. & Harvell, C.D. (Eds). (2008). Coral disease handbook.

Guidelines for assessment, monitoring & management. Melbourne, Australia: Coral

Reef Targeted Research and Capacity Building for Management Program.

Reef Research Center. (n.d). What causes crown of thorn starfish outbreaks?. Retrieved

January 26, 2012, from

http://www.reef.crc.org.au/discover/plantsanimals/cots/cotstheory.html

Red-band disease [image]. (2008). Retrieved January 25, 2012 from

http://www.coralreefinfo.com/coralglossary/glossary_r.htm

Sutherland, K.P & Ritchie, K.B. (2006). White pox disease of the Caribbean elkhorn coral,

Acropora palmata. Retrieved January 26, 2012, from

http://isurus.mote.org/Keys/microbiology/chapter16_patterson-sutherland_ritchie.pdf

White-band disease [image]. (2010). Retrieved January 25, 2012, from


http://www.coralmorphologic.com/






http://www.coralreefinfo.com/























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White pox disease [image]. (2007). Retrieved January 25, 2012, from

http://soundwaves.usgs.gov

http://soundwaves.usgs.gov/



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Coral Diseases