Could Artificial Insemination Save Coral Reefs?

Marine biologists are borrowing from medical and veterinary science in a bold experiment to create a sperm bank that could save the world's coral reefs.

Scientists led by Dr. Mary Hagedorn from the Smithsonian Institution are harvesting coral eggs and sperm from sites in Hawaii, Australia and the Caribbean with an eye toward restoring and rebuilding reefs damaged reefs, reports The New York Times.

Coral reproduces asexually, meaning that clones can grow from "parent" fragments, but genetic diversity depends on sexual reproduction.

To date, the team has frozen one trillion coral sperm, enough to fertilize 500 million to 1 billion eggs, along with 3 billion embryonic cells, the Times reports. 

That bank could be the key to saving coral reefs around the world that have been devastated by climate change: as the oceans warm, they become more susceptible to disease and to "bleaching," which starves reefs of the algae that is part of their food supply.

“Reefs at Risk Revisited,” released by the World Resources Institute in February 2011, estimates at least 75% of the world’s coral reefs are currently threatened by local and global pressures. Aside from climate change and ocean acidification, factors such as overfishing, coastal development and pollution pose the most immediate and direct risks, threatening more than 60% of coral reefs today.

In some areas of the world, the prognosis is even more grim. In the Caribbean, up to 80% of the region's coral has been destroyed, reports the Times. Just ask an avid scuba diver: the reefs look dramatically different than they did just 10 years ago.

For now, team's activities are limited to sperm and egg harvesting expeditions around the world, but their bank could be an insurance policy if reef conservation efforts fail.

If the current rate of decline continues, most of the world's reefs could be gone by 2050 -- which would, in turn, threaten the estimated one-quarter of all marine species that rely on its existence, reports the Times.

"Protecting fish communities, making sure water quality is good, all of those efforts can buy decades of time," Nancy Knowlton, a prominent coral-reef biologist at the Smithsonian, told the Times. "But if we continue on this greenhouse-gas emissions trajectory, the only place we’re going to be able to find many corals will be in Mary’s freezers."

[via The New York Times]

For more on the threat to coral reefs: