According to a paper set to appear Friday (8/15) in the journal Science, the downward spiral started when people first began killing off reef-frequenting large fish, turtles, seals and other top predators or herbivores a process that started thousands of years ago in some parts of the world and just a century or so ago in others.
"What really struck us was the universality of the decline trajectories," said Karen Bjorndal, one of 12 authors on the paper and zoology professor and director of the Archie Carr Center for Sea Turtle Research at the University of Florida. "It didn't matter if we were looking at the Red Sea, Australia or the Caribbean. As soon as human exploitation began, whether in the 1600s in Bermuda or tens of thousands of years ago in the Red Sea, the same scenarios were put into play."
The project is an outgrowth of research published in 2001 that tied overfishing to worldwide declines of coastal ecosystems. That paper argued that overfishing disturbs the ecological balance of marine environments, with the killing of green sea turtles, for example, ultimately contributing to the die-off of sea grasses. The authors of the current paper, who were among the scientists involved in that research, zeroed in on coral reefs, long seen as seriously threatened by modern pollution, global warming and diseases that cause the coral organism to die and "bleach," its mosaic of colors turning a uniform skeletal white. The goal: reconstruct the ecological history of the reefs from before the first people appeared to fish them some 40,000 years ago to the present era.
The scientists pored over historical and archaeological records surrounding major reef systems in 14 regions in the
Contact: Karen Bjorndal
University of Florida