Failure to account for the role of older fish in maintaining healthy populations may help explain the recent collapse of some major West Coast fisheries. The Pacific Fishery Management Council has declared several stocks of groundfish--a group that includes numerous species of rockfish and other bottom-dwelling fish--to be overfished. Tight restrictions were imposed to allow the overfished populations to recover, causing economic hardship for many in the West Coast fishing industry. Recovery of some stocks is expected to take decades.
One way to prevent such problems may be to establish marine reserves--areas where fishing is not allowed and fish populations are able to age naturally.
"Marine reserves are the only good way of protecting the full age structure of a population of fish, so that at least some of the population ages naturally," Berkeley said. "There may be other approaches, but no matter how you manage the fishery, you can't have a full complement of age classes unless some part of the population is off limits."
Other research presented at the symposium includes new findings about genetically distinct populations within the geographic ranges of some marine fish species, as well as evidence that successful breeders may be few and far between in some populations. These and other findings further undermine fundamental assumptions of current fisheries management, Berkeley said. "These are all things that should make us stop and think about how we manage fisheries," he said.
Berkeley and his collaborators have published recent papers on their research and its implications for fisheries management. Findings on the influence of maternal age on larval g
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Contact: Tim Stephens
stephens@ucsc.edu
831-459-4352
University of California - Santa Cruz
19-Feb-2005