Coral Reefs Practice (key)

Legislation in some areas has been effective in preventing further coral reef loss. In Australia, zoning laws require individuals who have collector's licenses to collect only in certain areas. Collectors have been able to gather 45 to 50 metric tons of material with no measurable effect on coral reefs. Facilities have been established to measure cyanide levels in live reef fish. The percentage of fish testing positive for cyanide has declined from 80% to 30% in the past five years. Facilities have been able to make a positive impact on coral reef preservation efforts.

Coral harvesting methods cause damage to coral reef ecosystems faster than the ecosystems can recover. Blast fishing is used because it maximizes the harvesting of fish, but it is also destructive to surrounding coral. Cyanide harvesting has similar effects. It can often kill coral along with the fish that it is targeting. Coral harvesting targets coral. If large portions of coral are removed it is difficult for the ecosystem to recover, as the coral as essential for the ecosystem and grows slowly over a period of many years.

a. control starfish populations.

c. fragile, highly complex community.

The polyp uses its tentacles to capture and ingest the phytoplankton it eats. The tentacles are also the primary means of defense for the polyp. They conceal the stinging nematocyst cells. The tentacles are also used to clear away debris from the mouth of the polyp.

a. planulae

a. farming of coral organisms for trade.

b. clean up algae and decayed matter.

Zooxanthellae and coral have a mutualistic, symbiotic relationship. Coral obtains oxygen and organic products from the algae that live within them. These algae also help the coral remove waste. The zooxanthellae obtains needed carbon dioxide and needed nutrients from the coral. The coral also provides the zooxanthellae with a protected habitat. Because both organisms derive a benefit from their relationship, it is considered mutualistic.

When too much ultraviolet radiation penetrates coral ecosystems, the photosynthetic processes of the zooxanthellae can be disrupted. Loss of zooxanthellae is the ultimate cause of coral bleaching.