Biology Reference
In-Depth Information
Common Mergansers, which frequent freshwater creeks, lakes, and other areas
with waters clear enough for them to hunt fish and aquatic insects by sight.
(Richard Bohnet)
Alameda Creek is a strange modern hybrid of a stream. Its waters are
among the most intensively replumbed in the Bay Area, and lands around
it are becoming increasingly urbanized. Yet Alameda Creek has the poten-
tial to be the most productive Steelhead habitat in the entire region. Its
watershed covers more than 700 square miles, and its banks contain some
of the most complete collections of native fish and amphibians in the re-
gion. At the same time, its flows have been so drastically manipulated that
the waters in its three subwatersheds now seldom mix.
Indeed, only a fraction of the water that once naturally flowed from
Alameda Creek's extensive watershed enters the bay. What little isn't put to
human use flows into the creek's 12-mile lower reach, which runs through
a concrete channel into downtown Fremont and shoreline salt ponds.
Built to handle massive floods, the channel is almost devoid of tree cover,
with sluggish flows that heat up easily in the sun. Yet upstream of the Fre-
mont flood-control channel, a good portion of Alameda Creek and its
tributaries run through rural cattle ranches, parklands, and publicly
owned watershed, constituting some of the most promising spawning
grounds for anadromous fish in the entire Bay Area.
The big systems are forever changed. The Sacramento, the San Joaquin
and the Tuolumne rivers: they're never going to be what they were. The
smaller systems are places with more potential,” says Tim Ramirez. The
former director of the Tuolumne River Trust, Ramirez manages the natu-
