Fishing Down Marine Ecosystems
In a research article in Science magazine Pauly et al. report that the kinds of fish harvested from the world's seas have changed from 1950 to 1994. In the process they call fishing down the food web, fishermen take the biggest, most profitable fish first, when they are gone, they go after the next most profitable fish. This has changed the ecosystems of the world's oceans by removing the top predators, destroying fish habitat, and changing the age structures of many populations of fish. The authors point out that this pattern of exploitation is not sustainable.
We discussed the Pauly paper with Elliott Norse, co-founder and director of the Marine Conservation Biology Institute in Redmond, Washington. While writing a report in 1980 for the President’s Council on Environmental Quality, Dr. Norse coined the term biological diversity to describe the variety of life, from genes to species to whole ecosystems, that the world is losing due to human activities. Since then, the idea of biological diversity has played a prominent role in environmental protection legislation and has entered the lexicon of scientists, journalists, and activists.