BOB HIRSHON (host):
Protecting elder fish. I’m Bob Hirshon and this is Science Update.
Many varieties of fish live to be a hundred or more years old, growing bigger with each year. University of Washington marine ecologist Lewis Barnett explains that as fish age, they may breed earlier, produce more eggs, and occupy different areas and depths.
LEWIS BARNETT (University of Washington):
In many species, the young fish will settle and live in shallower near shore, and as they grow and mature, they move to deeper off shore habitats.
Having a diversity of ages keeps fish populations healthy. But in the journal Current Biology, Barnett and his colleagues report that fishing pressures have led to reductions of up to 90% in the senior fish demographic. To protect these big old fish, they suggest maximum size limits for many species, and the creation of no fishing zones, where at least some fish can live well into their hundreds. I’m Bob Hirshon, for AAAS, the science society.