Biology Reference
In-Depth Information
scientific names. These are snails with a rosy internal shell that cruise the sedi-
ment on a muscular foot.
As the
Longfin
crew repeats the otter and mid-water trawls at eight stations
during the course of that August day, I see other forms of bay life. A midsized fish
called a White Croaker shines with a white-gold purity in the sunlight, belying the
poisonous mercury that tends to build up in its tissues (see the California De-
partment of Health Services illustration on p. 177). Most difficult for the crew to
handle are the Bat Rays, whose tails include barbed spines that can make a
good nick in a forearm. The crew breaks off spines entangled in the net to avoid
unintended jabs. A smaller version of the ray, a skate, looks up at me with half
dollar-sized dark circles that I soon notice aren't its actual eyes, just a diversion
for would-be predators.
Onboard the
Longfin
, followed by cawing gulls and inquisitive cormorants, the
bay seems implacably grey. I am thankful that the crew has brought so much of
what lies obscured under the surface up to the deck for me to see. It is from these
trawls that we know what lives in the bay, and how species change from season to
season, and year to year. Whatever they draw from the bay, the crew knows it's
more likely to be slippery and slimy than monstrous. As Kathy Hieb remarks, “most
of the things that come up in the net don't bite us.”
ARO
Amid the finny, feathered, and many-footed residents of the bay are more
than a few mammals. As the most sensitive to human disturbance, these
species have gone into a sharp decline since the years when Sea Otters,
River Otters, Steller's Sea Lions, and beaver were seen in abundance
around the bay. Those that remain are versatile survivors, their popula-
tions having held through recent decades of industrial exploitation. As
environmental conditions improve, mammals such as beaver and mink
appear to be returning to estuary watersheds.
California Sea Lion
The California Sea Lion (
Zalophus californianus
) is familiar to most peo-
ple as the trained seal of circus and marine park shows. A sable brown
coat, streamlined body, large front flippers, and visible ear flaps distin-
guish the California Sea Lion from other bay pinnipeds such as the Har-
bor Seal. Though two other species of sea lions frequent the Central Bay,
the wet, dark heads visible along San Francisco's waterfront are most often
California Sea Lions.
