Coral Reefs Marine Ecosystem: Living Animal Colonies

• Growing conditions• Sunny, shallow, clear, salt water• Temps: 75-88 degrees

Fahrenheit• Salinity: 34-37 parts out of 1000 • Tropics and Subtropics

• Covers 0.2 % of ocean floor• 1 million+ species of fish,

invertebrates, algae• 5-10 thousand years old

Worldwide Coral Reefs

Found within 30 degrees of equator

Rainforests of the Seas

• 25% of all ocean biodiversity

• 600,000 - 9 million reef species, estimated

• Indo-Pacific region = most biodiverse

• Eastern Pacific region = least biodiverse

Facts About Coral

• Phylum: Cnidaria

Class: Anthozoa

• 800 species of reef-building coral

• Scleractinians a.k.a. Stony Coral•Build reefs

•Composed of Polyps

•Stacks of polyps over the years create a coral reef

Variations of Coral Reefs

Barrier Reefs• A coral reef that

parallels the shore but is separated from the landmass by open water

• The Great Barrier Reef– Contains over 2,900

individual reefs– Stretches over

1,600 miles– Can be seen from

outer space

Fringing Reefs• Most common reef of the

Caribbean and Red Sea• Directly attached to a shore or

borders it with an intervening shallow channel or lagoon

• Can grow hundreds of yards from shore, but usually located near shore

• May contain seagrass meadows and areas of patch reef

• Found in the tropics in which the water is between 64°F and 86°F

Fringing reef off the coast of Eilat, Israel

Atoll Reefs• An island of coral that encircles a lagoon

partially or completely• How atoll reefs form:

1. Corals begin to settle and grow around an oceanic island forming a fringing reef.

2. As the reef expands, the interior island usually begins to subside

3. Fringing Reef turns into barrier reef4. When the island completely subsides beneath the

water leaving a ring of growing coral with an open lagoon in its center, it is called an atoll.

Atolls of Belize

Kayangel AtollPop. 138

Other Variations• Patch reef – an isolated, comparatively small

reef outcrop, usually within a lagoon or embayment, often circular and surrounded by sand or seagrass. Patch reefs are common.

• Apron reef – a short reef resembling a fringing reef, but more sloped; extending out and downward from a point or peninsular shore.

• Bank reef – a linear or semi-circular shaped-outline, larger than a patch reef.

• Ribbon reef – a long, narrow, somewhat winding reef, usually associated with an atoll lagoon.

• Table reef – an isolated reef, approaching an atoll type, but without a lagoon.

• Microatolls – certain species of corals form communities called microatolls.

Hazards to Coral Reefs

Coral Bleaching

Human Abuse

Ocean Acidification

Coral Bleaching

• What is coral bleaching?– Elevated temperatures– Disease or stressful

environmental conditions• Strong oceanic currents• Silt runoff• Elevated volcanic activity

– Loss of algae

Coral Bleaching

• What is the damage?– Can recover– High mortality rate– (2005) 20% destroyed, 50% at risk

Ocean Acidification

• The ocean absorbs about ¼ of the CO2, which greatly cuts down on the greenhouse effect

• As the levels of CO2 have risen due to global warming, the ph level has also gone down due to the higher carbonate levels that occur from CO2 absorption

• Also, the temperature of the ocean is increasing as the climate around it is also increasing

• This is called Ocean Acidification

Ocean Acidification

• This is a problem for coral reefs because it becomes difficult for coral to calcify and grow its structure as the oceans become more acidic.

• Scientists are unsure exactly how resilient the coral reefs will be to the increase in ocean acidity.

Ocean Acidification

OVERUSE & ABUSE

Cultural Eutrophication

• “Eutrophication is a process where bodies of water receive excess nutrients that stimulate excessive plant growth.”

• Cultural eutrophication is when human activity augments this process.

Sources of Etrophication

• Farming

• Mining

• Untreated sewage

• Other coastal dumping

• Phosphate-laden cleaning products

• Refinery on Australian coast (above)• Port of Aqaba (Jordan) ships phosphate fertilizer• Fosters favorable plants for Crown of Thorns starfish in Thailand and Australia

Sedimentation

Primary Sources of Sedimentation

• Construction/deforestation

• Farming/mining

•Moving land creates large quantities of sediment•Less vegetation to slow runoff

•Irrigation runoff•Moving land

Unsafe Fishing

• Cyanide and Dynamite fishing is very destructive

• Prominent in Philippines

• 90% of its reefs are destroyed or beyond recovery

Carelessness and Recreation

Boats running aground

Dropping anchors

• Stepping on coral• Breaking off pieces as souvenirs

•

•

Sold as souvenirs • Home aquarium industries•

Coral CrisisCoral reef scientists and managers from 45 countries met in 2006 at the ITMEMS conference in Mexico. They reported the emerging impacts of climate change on coral reef ecosystems.

"There is no longer any doubt that the Earth's climate is changing, causing rapidly warming seas and ocean acidification. Warming seas are causing increased mass coral bleaching and mortality, with little evidence that corals and their symbionts can evolve fast enough to keep pace."

The International Coral Reef Initiative is particularly interested in your recommendations of how to deal with the situation. They plan to use your recommendations for a major campaign to promote reef conservation during the 2008 International Year of the Reef.

1. NOAA Coral Reef Watch (CRW)a. Satellite sea surface

temperature data2. National Coral Reef

Ecosystem Monitoring Program (NCREMP)a. Local shallow-water

coral reef ecosystem

3. Coral Reef Early Warning System (CREWS)4. NOAA Comprehensive Report

a. Called for by US Coral Reef Task Force in the US National Action Plan to Conserve Coral Reefs

Team Suggestions

Resources• http://www.cotf.edu/ete/modules/coralreef/CRmain.html

• http://coris.noaa.gov/

• http://www.oceanicresearch.org/education/films/crrain.html

• http://www.eoearth.org/article/Coral_reef

• http://www.cotf.edu/ete/modules/coralreef/CRanthro.html

• http://reefrelief.org/