Species loss tied to ecosystem collapse and recovery The world's
oceans are under siege. Conservation biologists regularly note
the precipitous decline of key species, such as cod, bluefin
tuna, swordfish and sharks. Lose enough of these top-line
predators (among other species), and the fear is that the
oceanic web of life may collapse. In a new paper in Geology,
researchers at Brown University and the University of Washington
used a group of marine creatures similar to today's nautilus to
examine the collapse of marine ecosystems that coincided with
two of the greatest mass extinctions in the Earth's history.
They attribute the ecosystems' collapse to a loss of enough
species occupying the same space in the oceans, called
"ecological redundancy." While the term is not new, the paper
marks the first time that a loss of ecological redundancy is
directly blamed for a marine ecosystem's collapse in the fossil
record. Just as ominously, the authors write that it took up to
10 million years after the mass extincti