- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Humans to Blame for Coral Decline
2 July 2001 7:00 pm
BERKELEY, CALIFORNIA--The most important species of coral in the Caribbean have been dying since the 1970s at tremendous rates, and the once majestic reefs are overgrown with algae. The main suspects include human activities, such as overfishing and pollution. Now, a paleontologist has bolstered the evidence that humans are to blame, by showing that Caribbean reefs have always been inhabited by the same species during the last 220,000 years--but have only recently started changing drastically.
To identify past trends in coral reef ecology, John Pandolfi of the Smithsonian Institution's National Museum of Natural History in Washington, D.C., examined ancient reefs in the Caribbean that were left high and dry when sea level dropped during the ice ages and the islands rose. He made numerous 40-meter-long surveys of fossil reefs on San Andres, Curaçao, and Barbados, counting every coral species.
The communities had the same composition of coral species at the four time intervals--220,000, 190,000, 125,000, and 104,000 years ago respectively--that Pandolfi described here on 29 June at the North American Paleontological Convention. Elkhorn coral (Acropora palmata), made up about 80% of all the coral. Since 1973, however, this species has become exceedingly rare in the Caribbean. Another 15% of the coral community was comprised of five other species--always the same ones--in every survey. Another 24 rare species that made up the remaining 5% also showed up every time too. "I almost fell off my chair when that came out," Pandolfi says. The reefs didn't always exist during those 220,000 years, but when they reappeared, they had the same community structure each time. That means that the argument that reef ecology may change all the time doesn't fly, says Pandolfi: "People can't say we don't know what's normal."
The baseline provided by the fossil record reveals "a profound change that's unprecedented in recent geologic history," says John Ogden, a marine ecologist at the University of South Florida in St. Petersburg. "It's difficult to lay that at the feet of any cause other than humans."