Biogeography of Elkhorn Coral - … the shallow waters of the ocean lie coral reefs, ... where the majority directly or indirectly derive their food and income from. ... The polyp

Biogeography of

Elkhorn Coral

By: Sabina Mastrolonardo

April 10th

2015

ENVR 4060

(Acropora Palmata)

Biogeography of Elkhorn Coral

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Executive Summary

Biogeography is a broad type of science defined by studying the past and present geographic

distribution of plants, animals, and other organisms1. Studying biogeography gives notice to how

incredibly diverse life on Earth is that we share by helping us better understand its wide diversity

affected by history, climate, and behaviour. Biogeography can also help us reach the key

questions of why certain species thrive in one area of the world and are vulnerable in another.

This all together allows for greater awareness, understanding and true appreciation for the

abundant biodiversity surrounding us, and even just how closely related we humans truly are to

the extensive spread of animals. Species globally are disappearing at an alarming rate, and the

increasing need for conservation of these animals and their habitats has never been more crucial,

not only for their survival but for humankinds as well1. The following report will take you under

the sea to explore the fascinating world of coral reefs, and the biogeography of the most

important reef building coral species, Elkhorn coral.

Elkhorn coral (Acropora palmata) is known to be an important reef-building species of coral.

Over the last 10,000 years, Elkhorn coral has been one of the three essential Caribbean corals

contributing to reef growth and development2. It is structurally complex with many large

branches that resemble elk antlers, hence the name origin, and this arrangement provides vital

fish and marine invertebrate habitats for butterfly fish, parrot fish, lobsters, shrimps and many

other reef fish and organisms3 (Figure 1). The International Union for Conservation of Nature

(IUCN) Red List of Threatened Species since 2008, has Elkhorn coral listed as a Critically

Endangered species, with much of their populations persisting at low abundances and others

persevering to a decline4. With the current trend of immense species loss continuing without


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growth increase, Acropora palmata requires abrupt exploration, conservation and monitoring

conducted on a regional scale5.

Figure 1: Biodiversity thriving around Elkhorn coral


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Table of Contents

Title Page

Executive Summary .......................................................................................................................1

Table of Contents ...........................................................................................................................3

1.0 Introduction ..............................................................................................................................4

2.0 Evolutionary History ..............................................................................................................6

2.1 Life’s Beginning .....................................................................................................................6

2.2 Taxonomy ...............................................................................................................................7

2.3 Genera Acropora ....................................................................................................................8

3.0 Current Distribution ................................................................................................................8

3.1 General Coral .........................................................................................................................8

3.2 Elkhorn Coral .......................................................................................................................10

4.0 Elkhorn Coral.........................................................................................................................11

4.1 Species Description ..............................................................................................................11

4.2 Biology and Endosymbiosis .................................................................................................12

4.3 Diet .......................................................................................................................................13

4.4 Reproduction ........................................................................................................................13

4.5 Population .............................................................................................................................14

4.6 Threats ..................................................................................................................................14

5.0 Future Threats .......................................................................................................................17

6.0 Conservation ...........................................................................................................................19

6.1 Current ..................................................................................................................................19

6.2 Marine Protected Areas ........................................................................................................19

6.3 Top-down, Bottom-up Management Strategies ...................................................................20

6.4 Coral Nurseries Reaching Success .......................................................................................20

7.0 Conclusion ..............................................................................................................................22

Works Cited ...................................................................................................................................23

Figures Cited ..................................................................................................................................25


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1.0 Introduction

Over 70% of the vast surface of Earth is covered by oceans. These oceans support 80% of the

world’s total biodiversity and also produce 50% of the oxygen in the atmosphere for human

consumption6. Due to the oceans extreme importance and people’s awe and appreciation for

them, around half of the Earth’s population live in close proximity to different coastal regions6.

Within the shallow waters of the ocean lie coral reefs, a highly diverse colourful ecosystem

although beautiful to explore - are vital to marine organisms but also to the welfare of human

populations. Millions of people in fact depend upon a thriving coral reef for their livelihoods and

in small island countries as the reefs are relied upon to attract tourists, scuba divers and

snorkelers4. There are more than 450 million people living within 60 kilometers of coral reefs,

where the majority directly or indirectly derive their food and income from. Properly managed

coral reefs are able to yield an average of 15 tons of fish and other seafood per km2 annually

4.

Coral reefs distribution takes up only a tiny fraction, 0.2% of the world’s ocean area, while

containing 25% of all marine fish species7. The fascinating world of coral reefs can even be seen

from space, for example the world’s largest coral reef is the Australian Great Barrier Reef, more

than 2,000 km long and up to 242 km wide where the corals in the ecosystem are remains of

ancestors from millions of year’s prior7.

So what exactly is a coral? At first these colourful strange rock shapes may not have you believe

that corals are an animal but in fact they are. A captivating world filled with history that

scientists are still trying to uncover today, is what our oceans are comprised of. Corals are sessile

but coral reefs in their entirety are a part of a large community of other corals and living

organisms in symbiotic relationships8. They begin to form when a tiny free-floating living


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individual polyp attaches and initiates multiplying by the thousands. The polyp forms are found

inside corals, some more difficult to spot than others (Figure 2), as essentially a small tube with

tentacles around a month, allowing the polyp to capture its prey this way. Only on the outer

surface of corals are the living polyps. Underneath are the several layers of past polyps that died

millions upon millions of years ago, in addition to other sea animals that once lived on the reef

and are now cemented into it, which has all helped to build up the corals size over time8.

Coral reefs reach these large colourful homes because of the successful endosymbiosis that they

make between the reef-building polyps and also with an algae, named zooxanthellae

(pronounced zo-ZAN-thell-ee)7. Reef-building coral polyps and the zooxanthellae are a perfect

example of a mutualistic relationship, where two organisms as partners benefit from one another

in their lives7. The endosymbiosis for coral with a species of algae, and small organisms are

imperative in order for their common existences to flourish9. It is plain to see the incredible

network that goes on in our

oceans as - coral reefs are to

tropical seas what rain forests

are to tropical land areas, as they

provide countless habitats for

other marine species9.

Figure 2: Close up of Elkhorn coral, revealing numerous polyps


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2.0 Evolutionary History

2.1 Life’s beginning

Scientists, biologists, and archaeologists have debated the order of the evolutionally record of

animal phyla for many years, while new discoveries add even more genetic and molecular

evidence to the puzzle. According to biologists, almost all of the major animal body plans on

how species are categorized that are observed today, appear to be from the fossil record over 500

million years ago at the beginning of the Cambrian period9. Following the Cambrian explosion

over 540 million years ago, was a time when all those major phyla we see today diverged from

single-celled into multi-cellular organisms10

. There have been several disk-shaped impressions

made, now identified as medusoids (free-swimming jellyfish) types but, many appear to have

been attached to the bottom of the seafloor and none bear clear structures that would place them

in a living group. Some evidently have tentacles around their margins, and this suggests a close

group relationship to the phyla Cnidaria10

. Furthermore, recent descriptions of very small

phosphatized fossils that precede the Cambrian by 25 million years or more have validated the

presence of Cnidarians that may even be from the stem Anthozoans: the corals and sea

anemones10

. Other opinions of corals in specific were present soon before 490 million years ago

even and then diversifying into the many different species a few million years later11

.

Nevertheless of the above research and the precise date of how many millions of years ago that

the animal corals were first present, they rose given life’s biological history and their past

relatives in the Metazoan era9.

65 million years ago, was the most recent Cretaceous–Paleogene extinction or more commonly

known as the dinosaur extinction. This event was a large-scale mass extinction of animal and

plant species in a geologically short period of time giving Earth’s history of geology and


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biogeography12

. Now with every action, comes a reaction, and as devastating as this event was it

also seemed to give a remarkable rise of new forms and types of species, filling empty niches.

Through natural selection, asexual and sexual reproduction means, time, symbiosis, along with

many other important factors, the living animal diversity we see today scientists say bloomed

after this time12

.

Taxonomy5

Kingdom: Animalia

Phylum: Cnidaria

Class: Anthozoa

Order: Scleractinia

Family: Acroporidae

Genus: Acropora

Species: A. palmata

2.2 Taxonomy

More than 95% of all marine animals are invertebrates - those lacking backbones9. Sponges are

from the phylum Porifera and are the simplest example of an animal that lack true tissues.

Following the biological classification after sponges is the phylum Cnidaria, consisting of a

diverse group of over 9,000 known different species of Cnidarians of aquatic animals which

include corals, sea anemones, jelly fish and hydrozoans13

. These organisms also bear tentacles in

one of their forms9. Following the two above mentioned phyla’s are the Echinoderms including,

sea stars, sand dollars, sea cucumbers, etc. Then the phylum Chordata, which humans are a part

of and the list goes on with many free living worms, crustaceans like shrimps and lobsters,

cartilaginous fishes, boney fish, reptiles, birds, etc.7

Figure 3: Elkhorn coral colony in Utila, Honduras


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2.3 Genera Acropora

Acropora are in the family Acroporidae, which include three other genera: Montipora,

Anacropora, and Astreopora14

. Acropora is a diverse coral genus (more than 120 extant species)

and provides a major component of modern reef coral diversity all around the globe, with its

greatest diversity located in the central Indo-Pacific15

. The earliest known record of the genus

arose in the Late Paleocene (65–54 million years ago) in Somalia15

. The first record of Acropora

dominating a reef structure comes from the Late Oligocene, 28–23 million years ago in Greece15

.

Lastly, it is commonly expected that the species composition of surviving corals, including

Acropora, was most strongly influenced by events such as the Panama closure and Plio-

Pleistocene sea level fluctuations in the last two million years15

. Acroporids were historically

prevalent in the Caribbean due to high growth rates and reproducing successes; evidence shows

continuous habitation of the Caribbean by Acroporids throughout paleohistory (since 3.6–2.6

million years ago)14

.

3.0 Current Distribution

3.1 General Coral

Corals survive and succeed within a very narrow range of environmental parameters such as

temperature, depth and salinity. Even small changes to the marine environment can heavily

impact corals and the reef communities they support. Recent climate changes, as well as other

impacts are having a serious effect on the ability of coral reefs to prosper, and it is generally

accepted that almost all coral reefs will become seriously degraded, and possible even disappear

entirely if conditions do not soon change7.


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There are factors influencing the distribution of corals which include: light intensity,

temperature, emersion, sedimentation, salinity, etc. The distribution of where coral reefs grow

are confined to shallow ocean waters of the tropics and subtropics because the tiny animal polyps

and algae need warm water to thrive, they generally cannot survive in temperatures below

19°C16

. Corals also require plenty of sunlight, so most reefs are found are no deeper than 30

meters (100 feet), and therefore none grow below the photic zone in the ocean16

. The tug-of-war

situation here is the upper depth limit is defined by wave action, while the lower limit where

coral reside, is defined by light availability and sediment quantities. It is important to also

understand that polyps cannot grow in water that has been darkened by pollution, due to lack of

sunlight access, not to mention this is also the case for many algae species8.

There are three main centers or hot spots known for coral diversity which include: the Caribbean,

the Indo-Pacific and the Western Indian Ocean due to the prevailing currents in the tropical

oceans in a western direction17

. In the Caribbean, coral reefs contain a low 8% by surface area

diversity of the world's total coral reefs. This small size is due to a few reasons, one being the

fact that the inclusive size of the other wider reefs compared with the vast Indo-Pacific region.

Despite this size, the corals among the reefs provide critical habitat to thousands of species18

.

Because of the varied growth forms and strong skeletons coral possess in the Indo-Pacific,

Acroporid species can produce a wide range of morphologies including branching, tables and

plates. The plate and table forms in particular, allow for rapid utilization of limiting resources as

their growth rate, substrate coverage and, exposure to sunlight can be maximized while also

efficiently outcompeting most other species14

.


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Figure 4: The geographical extant (residency) of Acropora palmata

Before North and South America were joined by the Panama Isthmus, there was free movement

of genetic material between the Atlantic and Pacific Oceans, allowing populations to be

replenished if negative impacts occurred in one ocean. However, once the Panama Isthmus

formed some three million years ago, this was no longer possible. If and when a disturbance took

place that reduced the population, many would not be able to recover by genetic material re-

colonising from the other ocean as previously.

3.2 Elkhorn Coral

Elkhorn coral’s distribution range occurs in the Caribbean, the Gulf of Mexico, Florida, and the

Bahamas, also extending south to Venezuela, though it is not found in Bermuda16

(Figure 4).

Elkhorn coral has been

recognized at Fowey Rocks

offshore the Miami area

(25°37’ N) as its furthest

north extension5. Elkhorn is

one of three Acropora species

that occurs and thrives in the

western Atlantic and

Caribbean region19

.

This species coincides with shallow tropical waters in the ecosystem, while it prefers the outer

reef slopes exposed to wave action5. 22 meters in depth Elkhorn coral was logged for at Flower

Garden Banks in the Gulf of Mexico, but this is a recent range extension possibly due to the

results of climate change19

. Therefore the normal depth range for Elkhorn coral is 0.5-5 meters19

,


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but can also be seen up to 40 meters5. Acropora are an important species in the Caribbean Sea,

although the genus Acroporids have experienced a 95% decline in their abundance throughout

their range since the 1970s14

. The Caribbean suffers from regular heavy storms (hurricanes), and

therefore disturbance is high. This has led to the number of coral species found in the Caribbean

to be much lower than other areas of the tropics where disturbances are more moderate. In the

past, Elkhorn coral was the dominant species in shallow waters such as 1-5 meters deep

throughout the Caribbean and on the Florida Reef Tract16

.

4.0 Elkhorn Coral

4.1 Species description

Elkhorn coral (Acropora palmata), is known to be one of the three most important Caribbean

corals, a reef icon, that have contributed to the reef growth and development of essential fish

habitats16

. Acropora palmata’s appearance is the origin of its name as their shape resembles

large, thick and sturdy elk antlers and these branches of the coral can grow over two meters in

length (6.5 feet)16

. Their branches typically radiate outward, originating from a central trunk that

is firmly grounded on the ocean floor16

. Once Elkhorn coral forms into colonies, they are fast-

growing for a coral as their average growth rate is 5 to 10 cm annually and may eventually grow

up to 3.7 meters in diameter3. Behaviour of the branched colonies of Acropora have shown

competitive behaviours, as they gradually extend over other colonies of coral, such as

Montipora. Elkhorn coral have been listed as Critically Endangered, one mark away from being

extinct in the wild since 2008, beneath the IUCN’s Red List of Threatened Species (Figure 5)

5.

The devastating losses of Elkhorn coral will be, and currently are a major blow to the entire reef

ecosystem.


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Figure 5: Elkhorn coral classified as Critically Endangered (CR) on the IUCN Red List and listed on

Appendix II of CITES

Figure 6: On the left a healthy stony coral. On

the right is a stony coral that has lost its

zooxanthellae cells, resulting in a bleached

appearance

4.2 Biology and Endosymbiosis

Once colonies of Elkhorn are formed they are fast growing, as their branches increase in length

by five to ten centimeters (2-4 inches) every year, with the reported approximate maximum size

of colonies at ten to twelve years16

. Along with many other corals, Elkhorn coral have a special

endosymbiotic relationship with zooxanthellae, a species of algae. Despite their tiny size,

zooxanthellae are critically important to the existence of all coral reefs and ultimately to all the

creatures that depend on coral reefs in any way.

The inconspicuous zooxanthellae live inside the

corals tissues, providing the coral with essential

nutrients and food, which it produces through

photosynthesis19

. They also help remove waste

products from the coral. This is an essential

relationship because in return, the coral gives the

algae protection and contact to sunlight19

.

Therefore, a coral polyp that is left without

zooxanthellae cells for an extended period will most likely perish3. It is also the zooxanthellae

cells that give explanation to where coral’s pigmentation are from, as shown in Figure 6.

http://www.iucnredlist.org/apps/redlist/details/133006/0


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Figure 7: Elkhorn coral in shallow water

4.3 Diet

Elkhorn coral, just as many other corals, get most of their energy, nutrients, oxygen and other

needs from their symbiotic relationships, with organisms and algae16

. The diet Elkhorn coral

consume is organic by-products of photosynthesis. They may also eat live prey such as

zooplankton or very small fish, with the use of their tentacles of the polyps. A polyp extends its

stinging tentacles called cnidocytes, which contains a structure called a nematocyst to zap prey

floating by9.

4.4 Reproduction

The dominant means of reproduction

for Elkhorn coral is by asexual

reproduction. The mode of this is

performed by fragmentation, as new

colonies will form when individual

branches break off, reattaching to the

substrate16

. This asexual reproduction allows for a genetically identical rapid population growth,

which is particularly susceptible to storms, disease and bleaching events. Although that may be

the dominant form, Elkhorn coral are able to reproduce sexually as well. Once a year, during the

months of August and September an extraordinary display of corals perform broadcast spawning,

releasing millions of their gametes into the open water, in hopes many will be fertilized16

.

Colonies will begin to form when a settled larvae or a fragment is present. Settled larvae and

fragments are homogenous and lack branching. Therefore as they grow, protuberances develop

and this creates the main column and radial branches for the species16

. This is all possible


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because Elkhorn coral’s individual colonies are hermaphroditic, possessing both male and female

parts to release heaps of gametes.

4.5 Population

In the Caribbean since the 1980’s there has been a 80-98% loss of individuals for Elkhorn coral.

For instance, a report confirmed declines of Elkhorn coral on the order of 97% in the Florida

Keys, Jamaica, Dry Tortugas, Belize, St Croix and Puerto Rico5. There have been some signs of

recovery, as the population trend is stable5. From their population trend being stable, there are

some signs of recovering populations in some areas. For example, populations in St. Croix

showed increases from 2001-2003, although the larger colonies of Elkhorn coral are not

surviving due to larger colonies affected further by stressors5. Additionally, there are signs of

recovery in Puerto Rico and other parts of the southern Caribbean however, same idea that some

of these same populations have undergone subsequent regressions. Overall there has been a 38%

decline of destroyed and critical reefs in the Caribbean region, however there have been much

higher population declines when exposed to disease and bleaching5.

4.6 Threats

The various threats of Elkhorn coral and many other species of coral can be abiotic and biotic

factors. The main threats for Elkhorn coral, and the immense impact on the entire reefs are:

Disease, such as white band disease (WBD)

Storms

Bleaching

Algae overgrowth, competing for space

Sedimentation

Temperature and salinity variation

Predation

Low genetic diversity16


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Figure 8: Elkhorn coral showcasing WBD

The primary threat to most corals in general is the rise in sea temperature associated with

global climate change. This further leads to coral bleaching, a process where the symbiotic

algae are expelled leaving the coral fragile and vulnerable to a collective assortment of harmful

diseases19

. Climate change also brings on more compounding issues with more extreme

weather incidents, storms, increased ocean acidification, which impairs the coral's ability to

form, or reform their crucial skeleton19

.

The first and foremost threat to Elkhorn coral was found to be disease, specifically white-band

disease (Figure 8) which is also understood to be the primary cause for the region wide

Acroporidae decline during the 1980s5. Symptoms of WBD include a band of bare skeleton

surrounded by disintegrating coral tissue. WBD is thought to be a major factor in the decline of

Acropora palmata and Acropora cervicornis since the 1980s. The cause of white band disease is

unknown, but a bacterium is being investigated as a possible pathogen14

. The number of different

diseases among coral species affected, in addition to their distribution, have all shown drastic

increases within the last decade5. For example, a type of coral disease called epizootics caused a

significant loss and decline of coral of

Acroporidae in the Florida Keys5.


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Figure 9: Elkhorn coral

Acropora palmata is particularly environmentally sensitive, requiring clear, low turbid water to

live in. Unlike other corals, which can obtain nourishment from zooplankton, staghorn coral

species types are almost entirely dependent on the zooxanthellae for food, meaning sunlight is

essential19

. The other major threats are, increased temperatures resulting in bleaching, storms,

and other varies disease and factors5. Where there are localized declines of Elkhorn coral, is a

link with loss of habitat at the beginning stages because of algal overgrowth and sedimentation,

also predation by snails, ship groundings

with anchor damage, trampling, and marine

debris in the ocean environment5. A few

localized threats include; increased fisheries,

human developments from industry or

tourism, changes in native and invasive

species dynamics, pollution from agriculture,

and more, all having overwhelming impacts

on coral5. Overall, the intensified

anthropogenic stressors pooled with threats

of climate change of increases in coral

disease, frequency and, duration of coral

bleaching and ocean acidification place

Elkhorn coral, and other corals at high risk

of collapse5.

http://www.arkive.org/elkhorn-coral/acropora-palmata/#GlossaryTerm8


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5.0 Future Threats

Acropora palmata was once a very abundant species, but in recent decades it has remained at

low levels of abundance, with little to no signs of recovery and in certain areas of continued

decline19

. Elkhorn coral in the Atlantic for example are believed to be greatly threatened by

disease, temperature-induced bleaching, and physical damage from hurricanes. Potential causes

of decline for Acroporid species in the Caribbean are; hurricane damage, coral bleaching,

warming ocean temperatures, increased eutrophication, and diseases14

. What does the future

hold? No one knows exactly but we must be prepared with research, natural ranges of variations

and an understanding of how to combat future environment damages to coral reefs.

Many future threats may be from anthropogenic physical damage (ex. vessel groundings,

anchors, divers, snorkelers), coastal development, tourism, and predation are deemed to be

moderate19

. Years ago prior to the established tourism along coastal areas, the only real source of

income for local people came from fishing. This is how reefs quickly become heavily overfished,

causing an unknowing ecosystem collapsed. As an attempted solution to save reef ecosystem and

provide an alternative source of income for local people, scuba diving and snorkel based tourism

was actively encouraged by governments. This emerging tourism in the last booming 20-30 years

has provided vital income for the local people and has essentially helped the problems from the

past regarding over fishing and consumption.

However, regarding the complex ecosystems and day-to-day life in general, there must remain a

balance. The current worry about tourism continuing is if not managed correctly, will bring in

significant complications of its own. For example, an increase in hotels will need to be

constructed to accommodate tourists, which takes away from important nesting habitats for

turtles and marine life. More menacing examples of increased tourism include; loss of mangrove


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Figure 10: Elkhorn corals in an organized marine ecosystem

habitats which filter and clean water, preventing sediments from washing onto the reef, in

addition to loss of species and changes in predator-prey dynamics. Predators for coral currently

and that pose a threat in the future in the Caribbean include the polychaete worm, and a few

gastropod species14

. There is also competition between other coral species by means of

overgrowth, chemical defenses and ingestion could also cause mortality14

.

If the global temperature continues to increase, scientists worry that the ocean’s ecosystem will

change drastically, with many of the living organisms unable to adapt in the only environment

they have known for millions of years. Colourless corals are seen everywhere, as the warmer

ocean waters close to coral reefs cause coral bleaching. There are many factors regarding coral

bleaching and certainly climate change, leaving it as not the only cause but surely if the oceans

temperatures warm significantly - the reefs will further be in danger of extinction forthcoming8.


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6.0 Conservation

6.1 Current

Although Elkhorn coral are currently listed on the Convention on International Trade in

Endangered Species (CITES) Appendix II as Critically Endangered and under the United States’

Endangered Species Act as threatened, additional conservation actions are calling. Laws under

the United States also say it is illegal to harvest corals for commercial purposes. Elkhorn coral

included in the Acropora sp. constituted for 13 percent of the global coral trade between 1985

and 199719

. Coral is harvested for building materials, ornaments, jewellery, and aquariums19

.

Moving forward in some areas such as the Florida Keys National Marine Sanctuary, coral reef

rebuilding attempts are commencing by reattaching coral fragments, or culture and settle coral

larvae19

(see Section 6.4).

6.2 Marine Protected Areas

On the positive side, Elkhorn coral are present in many Marine Protected Areas (MPAs), some

which include Florida Keys National Marine Sanctuary, Dry Tortugas National Park, Buck

Island Reef National Monument, and Exuma Cays Land and Sea Park in the Bahamas5. Although

according to the IUCN, only a total of 2.2% of the world's oceans are protected, so as

conservation managers we must ask, are MPAs doing much and is this enough?6. Marine

Protected Areas are areas in which marine resources are protected to some extent. They are

typically designated by national government, although in some cases where multiple countries

are included in the area it can be a political nightmare to establish and manage successfully.

MPAs can be defined as, protecting the natural environment while allowing exploitation to

continue at a sustainable level, so that humans and the natural environment can happily

coincide17

. Approximately 27% of all coral reefs in the world are currently within a collection of

around 2700 MPAs17

.


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This may sound promising, but in reality the level of active management taking place in these

parks varies, and many are no more than parks on paper, known as “Paper Parks”, so they are

called MPAs but there is no enforced protection or management taking place. This is often used

as a political tool to appear like efforts are being made to protect areas, but in reality an MPA

will only work if human exploitation is managed in some way17

.

6.3 Top-down, Bottom-up Management Strategies

Conservation management techniques follow two main approaches: top-down and bottom-up

management17

. Both have their usages, and often a management plan will include components of

both to achieve success. Top-down management (or command and control) focuses on putting

rules and regulations in place which control the way people interact with the environment17

. This

is carried out by an organization (or individual) with authority over the area, and the idea is to

force stakeholders not to damage the environment. Bottom-up management on the other hand (or

community management) aims to encourage people not to damage the environment by providing

them with incentives. Stakeholders are given more power under this strategy and, if done

properly, probably has the highest chance of success as it avoids a lot of potential problems

associated with top-down management (ex. a lack of support amongst local communities)17

. In

both instances, tremendous thought must be given to what management approach should be

taken in order to reach successes with the help of communities, local people, stakeholders and

government.

6.4 Coral Nurseries Reaching Success

Lisa Carne, a marine scientist has been working on a project in Belize’s Laughing Bird Caye

National Park on growing corals by their fragments to have them colonize20

. Belize’s reefs are at

the center of the largest reef system in the western hemisphere, the endangered Mesoamerican


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Barrier Reef System, where corals are vulnerable from the unusual geography of the reefs and

thermal concerns. Carne witnessed the deterioration of the reefs with her own eyes in 1998 and

decided on the idea of transplanting conservation or “coral nurseries”. These nurseries are to

restore damaged reefs by taking coral fragments, hung like clothes on a clothesline, made from

pipes or other materials21

. By the coral floating freely in the water, they acquire great water

circulation, avoid being attacked by predators such as fireworms or snails, and largely survive at

a higher rate21

. Although this brilliant method is only used by a few people, not nearly enough

should be using it. Since 2006, Carne and her partners have systematically planted more than

8,000 coral fragments around Laughing Bird Caye National Park with roughly 80% of the corals

transplanted surviving. This type of work is critical because it restores the ecological integrity of

these habitats, and offers examples for approaches to rebuilding coral reefs in the future.

Another example is the National Oceanic and Atmosphere Administration (NOAA) having 27

different coral nurseries around Florida, Puerto Rico, and the U.S. Virgin Islands with various

associates21

. As ships smash their way through corals or storms take place, small bits of coral can

all be gathered as they would likely just perish buried under debris. In fact, Elkhorn and Staghorn

coral species both do extremely well in nurseries, as they reproduce predominantly via small

branches breaking off and reattaching somewhere new21

.

In 2006 after a tanker grounded on coral reefs in Puerto Rico, NOAA divers rescued 11,000

salvageable pieces of broken coral. That nursery has 2,000 corals in it and each year on a cycle

1,600 of those are transplanted back onto the seafloor. The 400 remaining corals are broken into

smaller fragments to restock the nursery once again. In the fall of 2014, a NOAA team also

worked with the University of Miami to rescue more than 200 threatened Staghorn coral colonies

being affected by excessive sediment in the waters off of Miami, Florida21

.


~ 22 ~

7.0 Conclusion

Coral reefs overall distribution cover less than 1% of the ocean seafloor but, they provide homes

to more than one quarter of all known marine fish species. Scientists estimate that there are more

than one million different species of animals and plants that live in, around and, depend on coral

reefs22

. Coral reefs or “ocean apartments” have the most diverse life of any ocean habitat – they

are filled with cracks, channels, crevices, and caves that provide shelter for many invertebrates,

small organisms and reef fish species including grunts, snappers, tangs and butterfly fish, etc.22

.

The animal coral, may be described as a large living rock formation formed by the growth and

deposits of corals over millions of years, which thrive with the relationships of other underwater

organisms. As the foundation of both a single coral head and the entire coral reef are collectively

limestone remains from skeletons of once-living coral polyps millions of years ago. It is the coral

reefs we see now that began growing far beyond our time here, millions of years ago and now

stretch across hundreds of miles in the ocean22

.

Elkhorn coral, apart of the genus Acropora contains 150 extant coral species, most of those

which can be found in the Pacific region14

. The biogeography of Elkhorn Coral is restricted to

shallow tropical or subtropical waters where they may form symbiotic relationships with other

organisms. Elkhorn’s populations are stable but require critically attention in many areas.

Over the last half a billion years there have been five mass extinctions, as our fossil record

indicates1. We must learn from what we know and act as guests on this planet, as humankind is

proving to impose a "sixth extinction", as we wipe out many species at an alarming rate.

“What we save, saves us”.


~ 23 ~

Works Cited

1. Macdonald, G. M. (2003). Biogeography: Introduction to Space, Time and Life. New York: John

Wiley & Sons Inc.

2. WoRMS (2010). "Acropora palmata (Lamarck, 1816)". World Register of Marine Species.

Retrieved 2011-12-09.

3. Wikipedia. (2014, May 14). Elkhorn coral. Retrieved February 2, 2015, from Wikipedia:

http://en.wikipedia.org/wiki/Elkhorn_coral.

4. IUCN. (2013, March 20). Coral reefs facts and figures. Retrieved January 26, 2015, from IUCN:

http://www.iucn.org/media/facts_and_figures/?12680/Coral-reefs---Facts-and-figures.

5. Aronson, R., Bruckner, A., Moore, J., Precht, B. & E. Weil 2008. Acropora palmata. The IUCN

Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 26

January 2015.

6. IUCN. (2013, September 3). About the IUCN Global Marine and Polar Programme. Retrieved

January 30, 2015, from IUCN:

http://www.iucn.org/about/work/programmes/marine/marine_about/.

7. Day, T. (2006). Oceans. In T. Day, Oceans Biomes of the Earth (pp. 94-113). New York: Chelsea

House.

8. Ricciuti, E. R. (2008). Oceans, Islands, and Polar Regions. In E. R. Ricciuti, Living Green

Oceans, Islands, and Polar Regions (pp. 5-25). Chicago: World Book.

9. Reece, J. B. (2008). Campbell Biology 9th ed. In J. B. Reece, Campbell Biology (pp. 55, 1162).

San Francisco: Pearson Benjamic Cummings.

10. Miller, K. B. (2014). The Fossil Record of the Cambrian "Explosion": Resolving the Tree of Life.

BioLogos, 16.

11. Wikipedia. (2015, February 23). Cnidaria. Retrieved February 2, 2015, from Wikipedia: FROM:

http://en.wikipedia.org/wiki/Cnidaria).

12. Stanley, G. D. (2006). Photosymbiosis and the Evolution. Science Mag, 857-858.

13. Levinton, J. S. (n.d.). Marine Biology Basic Facts. Retrieved January 20, 2015, from Global

Oxford University Press: http://global.oup.com/us/companion.websites/9780195326949/.

14. Syste, N., & Life, E. (2013). Genus Acropora. Retrieved from

http://www.eoearth.org/view/article/51cbedd77896bb431f69451f.

15. Wallace, C. C., & Rosen, B. R. (2006). Diverse staghorn corals (Acropora) in high-latitude

Eocene assemblages: implications for the evolution of modern diversity patterns of reef corals.

Proceedings of the Royal Society B: Biological Sciences, 273(1589), 975–982.

doi:10.1098/rspb.2005.3307.


~ 24 ~

16. Bruckner, A.W., 2002. Proceedings of the Caribbean Acropora Workshop: Potential Application

of the U.S. Endangered Species Act as a Conservation Strategy. NOAA Technical Memorandum

NMFS-OPR-24, Silver Spring, MD 199 pp.

17. Operation Wallacea Inc. (2014). Wallace Resource Library Demo 2014. Retrieved February 17,

2015, from Wallace Resource Library: http://wallaceresourcelibrary.com/.

18. Alevizon, W. P. (2013). Caribbean Coral Reefs. Retrieved February 16, 2015, from Coral Reef

Info: http://www.coral-reef-info.com/caribbean-coral-reefs.html.

19. Acropora Biological Review Team. (2005) Atlantic Acropora Status Review Document. Report to

National Marine Fisheries Service, Southeast Regional Office.

20. Marsa, L. (2014, April 22). How to Fix a Coral Reef. Retrieved January 30, 2015, from Take

Part: http://www.takepart.com/feature/2014/04/22/save-coral-reef-from-global-warming-ocean-

acidification.

21. Commerce, N. U. (2014, December 5). How NOAA Uses Coral Nurseries to Restore Damaged

Reefs . Retrieved February 16, 2015, from NOAA:

http://response.restoration.noaa.gov/about/media/how-noaa-uses-coral-nurseries-restore-

damaged-reefs.html.

22. Simon, S. (2013). Coral Reefs. China: Harper Collins.


~ 25 ~

Figures Cited

Title Page: http://aquaviews.net/explore-the-blue/coral-identification-types-of-coral-part-1/

Figure 1: http://www.coralreefphotos.com/wp-content/uploads/2013/10/Elkhorn-web-457x303.jpg

Figure 2: http://commons.wikimedia.org/wiki/File:Acropora_palmata_(Elkhorn_Coral)_closeup.jpg

Figure 3: http://diveinutila.com/images/stories/altonsimages/dive-in-utila/Coral_Hard_Elkhorn5.gif

Figure 4: http://maps.iucnredlist.org/map.html?id=133006

Figure 5: http://www.iucnredlist.org/details/133006/0

Figure 6: http://oceanservice.noaa.gov/education/kits/corals/coral02_zooxanthellae.html

Figure 7: http://www.tripadvisor.com/LocationPhotoDirectLink-g291963-d1520618-i53075066-

Belize_Diving_Services-Caye_Caulker_Belize_Cayes.html

Figure 8: http://www.nmfs.noaa.gov/pr/species/invertebrates/elkhorncoral.htm#description

Figure 9: http://turtleandray.com/en/?portfolio=elkhorn-coral-at-east-point-2

Figure 10: http://2.bp.blogspot.com/-

1XFpLjfPhvA/U1ffAzDpSFI/AAAAAAAAA1w/yGC36prKuCg/s1600/ACROPORA+FINAL+PIX.j

pg

http://aquaviews.net/explore-the-blue/coral-identification-types-of-coral-part-1/

http://commons.wikimedia.org/wiki/File:Acropora_palmata_(Elkhorn_Coral)_closeup.jpg

http://diveinutila.com/images/stories/altonsimages/dive-in-utila/Coral_Hard_Elkhorn5.gif

http://maps.iucnredlist.org/map.html?id=133006

http://oceanservice.noaa.gov/education/kits/corals/coral02_zooxanthellae.html

http://www.tripadvisor.com/LocationPhotoDirectLink-g291963-d1520618-i53075066-Belize_Diving_Services-Caye_Caulker_Belize_Cayes.html

http://www.tripadvisor.com/LocationPhotoDirectLink-g291963-d1520618-i53075066-Belize_Diving_Services-Caye_Caulker_Belize_Cayes.html

http://www.nmfs.noaa.gov/pr/species/invertebrates/elkhorncoral.htm#description

http://turtleandray.com/en/?portfolio=elkhorn-coral-at-east-point-2

http://2.bp.blogspot.com/-1XFpLjfPhvA/U1ffAzDpSFI/AAAAAAAAA1w/yGC36prKuCg/s1600/ACROPORA+FINAL+PIX.jpg



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