Biology Reference
In-Depth Information
GLANCING AT THE BAY
from a speeding auto or at the edge of the pier, it's
difficult to tell that it teems with a dazzling variety of life. With time and
patience, however, signs of life always materialize. For most observers,
birds are the first to move into sight: white gulls circling overhead, sander-
lings poking beaks into the smear of shoreline mud, or a black-and-white
Western Grebe, long neck arched for a fishing expedition.
Those who scramble down to the water's edge encounter an even
broader slice of estuary organisms. Empty crab carapaces, fish vertebrae,
and bottle-green strands of eelgrass offer a taste of what resides beneath
the opaque chop. Mudflats at low tide reveal the telltale breathing holes of
clams, worms, and invertebrates.
Observing fish requires more effort. Flatfish, crabs, sharks, and rays
can be seen wriggling within plastic buckets near anglers, or staring from
atop mountains of ice at Fisherman's Wharf.
Willets gather in the shal-
lows of former salt produc-
tion ponds at the Coyote
Hills Regional Shoreline.
This decrepit pipeline and
pilings still poke out above
the high tide line, but a re-
cent survey found 33,000
abandoned pilings lie invis-
ible beneath the bay's sur-
face. Some offer important
hard substrates for aquatic
creatures to latch on to—
a rare habitat in a largely
soft-bottomed bay. Many
old pilings contain creo-
sote, however, a wood pre-
servative that can be harm-
ful enough to marine life
that biologists would like to
see all abandoned pilings
removed.
(Kathleen M. Wong)
The extraordinary diversity of species found in the bay mirrors the
broad range of available environments. As a place where fresh and salt
water mix, and liquid ocean and dry land overlap, its waters and shores
embrace an ever-shifting blend of salinities, temperatures, substrates, and
currents. The resulting profusion of habitats draws a mix of coastal and
aquatic species to live side by side. The physical processes at work in the
water bring order to the locations and arrivals of bay species.
This chapter describes a number of representative invertebrates, fish,
birds, and mammals found in the ecosystem of the estuary. All are native
