Bleaching of Coral ReefsIn the Caribbean

By Colleen Farrell and Leah Salituro

What is a Coral Reef?

A coral reef is an ocean habitat where a large variety of animals and plants live. Coral is formed from coral polyps. When they die, they leave behind a hard, branching structure made of limestone. There are two types of coral: hard and soft coral. Hard coral had limestone skeletons which form the basis of coral reefs. Soft coral does not buildup reefs. Coral reefs grow in shallow, warm water usually near land and in the topics. They prefer temperatures between 70 and 85 degrees.

What is Coral Bleaching?

Coral Bleaching is when coral lose their color because zooanthellae which live within them through a symbiotic relationship, leaves the coral due to environmental stress. When a coral is fully bleached it will turn completely white. If the stress on the coral is not reduced then the coral could potentially die.

The Problem• Coral bleaching is caused by abiotic environmental stress

such as…– Increased sea water temperature– Ultraviolet light– Sedimentation– Toxic chemicals– Pollution

• Biotic factors that cause coral bleaching are...– Bacteria– Fungi– Viruses

• Abiotic and biotic factors cause zooxanthellae to be taken out of the coral leaving it white

• Zooxanthellae is an algae living within the coral’s tissue• Corals need zooxanthellae for nutrition, health, and survival• This problem started to occur frequently in the 1980s to the

early 1990s• Another big contributor to coral beaching is hurricanes

because they mix the cooler deeper waters with the coral reef’s warm water

Symbiotic Relationships on the Reef

• The algae Zooxanthellae lives inside sac of each coral polyp. Algae gives oxygen and nutrients to polyp. Then the polyp gives the algae carbon dioxide and other substances.

• Crabs camoflauge themselves by putting seaweed and sponges on their backs. The seaweed and sponges have more food choices.

• Fish with parasites allow other fish to pick off the parasites. One fish gets to eat and the other gets rid of the parasites

• Fish immune to the jellyfish’s tentacles hide within the tentacles to prey on other fish. The fish and jelly fish share it.

How Humans use Coral• Valuable for tourism, diving, snorkeling,

swimming, fishing and boating industries• Coral rock is used for building• Used in medicines such as anti cancer drugs and

sunscreen• Buying and selling of jewelry, living corals,

whole shells, and household decorations• Used in coral trade, aquarium trade, and shell

trade

Coral’s Use in the Environment

• Broken down to provide sand for beaches

• Islands can be created by an accumulation of coral rubble

• Controls how much carbon dioxide is in the ocean water

• Provide a sea defense by reducing island and beach erosion

Coral’s Use in Organisms

• Reefs attract fish• Serve as a habitat for different

types of fish and invertebrates• Alga can be produced on the reef

as a food source and for extraction of useful chemicals

• Provides energetic links with mangroves and sea grasses

Sun Algae Parrot fish

Barracuda Moray Eel

Biogeochemical Cycles• Carbon Cycle- The algae found in corals use carbon to

photosynthesize. If the corals are bleached and die, there will be too much carbon dioxide in the water. This would cause harm to plants and animals. Therefore, the carbon cycle at the oceanic level would be disturbed.

• Nitrogen Cycle- The algae within the coral is a big part of the underwater nitrogen cycle. Without it, there will be an excess amount of nitrogen in the water and too much nitrogen can kill many plants and animals in that area.

• Oxygen Cycle- The algae in the coral does photosynthesis, but if it is not there then where will all the oxygen in the water go? There will be too much oxygen which can also kill a lot of plants and animals around that area.

Problems if issue is not addressed

• Coral beaching can become more frequent by the year 2030 and can become annual by 2100 if greenhouse gas emissions are not reduced greatly.

• Climate change can potentially change the weather patterns and create more intense and more frequent natural disasters. These natural disasters can destroy coral reefs and also bleach them by bringing in cold water to the reefs.

• Coral is very important in controlling how much carbon dioxide is in the ocean water and if there are increased CO2 levels, due to climate change, than this could also bleach the coral.

Outlook on Bleaching

Possible Solutions• Create marine parks around them so

that fisherman and souvenir hunters will not harm the coral reefs

• Keeping a good watch on the coral can help because it will show scientists which areas are bleached and which are not (very useful information of scientist)

• Greenhouse gas emissions need to be greatly reduced in the next 20 to 50 years to make sure that coral reefs have food, protection, and enjoyment for future generations

The Plan

We want to decrease the emission of CFC’s into the environment. CFC’s are a direct cause of ozone depletion. The depletion of the ozone lets in more ultraviolet light. The ultraviolet radiation is an abiotic and preventable factor that causes coral bleaching.

Sources of Chloro-fluro-carbons

• Leaking coolant from refrigerators• Leaking coolant from air conditioners • Propellants for aerosol cans • Styrofoam insulation/ packaging • Medical sterilizers

Steps to Our Goal

How Participants Can Help

• When disposing of an AC unit or fridge make sure garbage company uses refrigerant recovery so CFCs don’t escape

• Buy ozone friendly products (marked)

• Write letters to companies that still put CFCs in their products

• Speak to others about issue

How to have our plan succeed 1. Encourage people we

know to decrease CFCs-right away

2. Get student involvement in schools to broaden our plan-6 months into plan

3. All Participants who follow these guidelines would have to sign a pledge so they stick with the plan-From start to finish

4. Educate the community about ozone depletion and CFCs -1 year for BOE acceptance

Why it will work?

As this graph shows the CFCs have started to decrease or leveled off. The Montreal Protocol was enacted in 1987 when 30 countries promised to phase out the production of products with CFCs. One can see how this lessened the atmosphereic abundance of CFCs and related substances. Although our plan won’t be worldwide it changes the use of CFCs in the community. This will contribute the natural restoration of the ozone layer. Eventually, this will decrease coral bleaching from ultraviolet radiation. Plan can also continue to function once goals are achieved. Ozone depletion is a long-term problem and our plan can be used continuously.

Benefits

For Coral Reefs

Corals affected by bleaching can usually return to their normal state if not prolonged. By participating in campaign against CFCs the coral can regain their pigmentation. Therefore, you and animals can profit from all coral has to offer the world.

In GeneralDecrease in ultraviolet radiation can decrease related problems like...-severe sunburns-skin cancers-immune system problems-health problems-lower crop yields-global warming

Save the Coral Reefs!Save the Coral

Reefs