ScienceDaily (Jan. 12, 2011) — Geologists at Brown University and the University of Washington have a cautionary tale: Lose enough species in the oceans, and the entire ecosystem could collapse. Looking at two of the greatest mass extinctions in Earth’s history, the scientists attribute the ecosystems’ collapse to a loss in the variety of species sharing the same space. It took up to 10 million years after the mass extinctions for the ecosystem to stabilize.

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.”

The research appears in Geology 2011   39(2):99.  Request a copy from Markus Library.