However, Prosperetti's theory, which he describes in the April Journal of the Acoustical Society of America, bursts that bubble, if you'll pardon the pun. A sphere of coral the size of a softball rests on biologist Gary Ostrander's desk. White hard coral have lost symbiotic algae that normally inhabit their tissues and provide vital nutrients and coloration. Over the past two decades, coral bleaching has increased at an alarming rate, says Ostrander, who is part of a large unaffiliated group of scientists monitoring the health of coral reefs around the world. Ostrander is now collecting some of the first data showing declines in fish populations associated with coral bleaching.
Coral are animals related to jellyfish and sea anemones.
The polyps deposit a hard calcium carbonate skeleton, to which they permanently attach. Coral continuously build onto the calcium carbonate skeleton, enabled by single-celled photosynthetic algae that live inside their cells and provide fats and carbohydrates. One symbiont cannot survive without the other. If the zooxanthellae leave, the coral dies, leaving only the bleached skeleton. Small amounts of bleached coral can regenerate.