Biology Reference
In-Depth Information
is a race against time, as seabirds and fish find herring eggs especially tasty.
The skiff might also nose around eelgrass beds, dragging a modified rake
behind it to retrieve clumps of vegetation and eggs to take back to the lab.
Most herring fishermen pay careful attention to the ripeness of the
schools in order to land the ripest individuals. But fishing for herring
eggs is not as lucrative as it once was, nor is the fishery as predictable. A
permit for a single vessel once cost $40,000-$60,000 but was worth much
less in recent years. In the last decade, the herring quota for all of San
Francisco Bay averaged around 3,000 tons. Only about 25 vessels remain
to land these fish, using gill nets, in the bay today. Market demand keeps
changing. In the meantime, the state continues to invest in the annual
biomass surveys and research that may keep this fishery sustainable in
years to come.
Of course, some people still fish just for fun. Locals continue to seek
out bayshore piers to spend a peaceful afternoon amid the seabirds,
sun, and waves. In the last few decades, however, new arrivals to the re-
gion have started fishing to feed their families off these same piers and
breakwaters.
A Save the Bay survey found that most of these fishers ate more bay-
caught fish per month than the amount recommended as safe for human
health by state health agencies. The five most frequently caught and eaten
fish species were Topsmelt, salmon, Striped Bass, White Croaker, and
perch. Testing of a variety of bay fish indicates that most fish are contami-
nated with multiple chemicals, including DDT, dioxin, PCBs, and mer-
cury. Different fish concentrate different contaminants: White Croaker
and Shiner Perch collect more PCBs; and Leopard Shark, Striped Bass, and
White Sturgeon collect more mercury. Less than 5 percent of fish harbor
excessive pesticides.
In general, bigger, fatter, longer-lived fish are more likely to accumu-
late contaminants over their life spans—which is why health advisories
now recommend that people eat less than two meals a month of bay-
caught fish, and children and pregnant women even fewer. From the bay,
White Croaker is the fish to avoid, because its habit of feeding on the bot-
tom, as well as the way it stores fat, make it among the most contaminated
species. State advisories also recommend avoiding Striped Bass over 35
inches in length.
As in all things, moderation is the key to bay fish consumption. It's not
that bay-caught fish should be avoided, but no one should eat too much
of it (see chart on next page). Since these fishing surveys, local agencies
and groups have worked hard to notify the fishing public of potential
health hazards via signage, advertising, and education in communities of
concern.
