What are corals and coral reefs?
Corals are animals, and their skeletons create reefs. The corals have microscopic, single-celled plants living in their tissues. The plant cells, or algae, give the coral extra nutritious compounds. The algae's energy prompts the coral to secrete a calcium carbonate skeleton. When many living and dead skeletons fuse over time, a coral reef is formed. Reefs are the largest structures made by living organisms.
What's wrong with the reefs?
Mostly, humans are what's wrong. Scientists say that 70 percent of the world's coral reefs will be wiped out in your lifetime. These are threats:
Sedimentation. Construction along coasts, mining or farming upstream and logging in tropical forests cause soil to wash downstream into the ocean and onto coral reefs, smothering the coral.
Fishing with explosives and poisons. Fishermen who bomb underwater to kill and catch fish are making rubble out of reefs. Those who use poisons are killing the coral.
Collection. Removing coral to be sold as jewelry or figurines or for use in aquariums.
Water pollution. Chemicals dumped near coastal waters poison coral and other marine life. And litter in the water can find its way to coral reef and smother it.
Careless recreation. Dropping anchors on reefs can crush or break the coral. Boaters also move into shallow waters, scarring the reefs.
Global warming. When oceans get too hot, coral loses its algae.
c 1997 Chicago Tribune. Distributed by Knight-Ridder/Tribune, Inc.
Pub Date: 09/23/99