Biology Reference
In-Depth Information
wild conditions by holding them temporarily in cages placed in brackish
water.
Hatcheries are not going to go away. For one thing, they have sustained
the commercial salmon fishery in California for more than 50 years. For
another, they have preserved the genetics of fish runs otherwise blocked
from breeding by dams.
Scientists are now weighing whether to use conservation hatcheries as
last-ditch attempts to preserve other species. One such hatchery could be
built to sustain the endemic Delta Smelt. Scientists originally learned the
ins and outs of raising smelt to produce fish for experiments. That know-
how may be all that stands between the smelt and eternal oblivion, says
Moyle. “It is not outside the realm of possibility that the only smelt around
will be in that rearing facility.”
When people think about salmon runs, the rural rivers and creeks in the
headwaters of the Sacramento and San Joaquin rivers are what generally
come to mind. But the bay is surrounded by 85 smaller watersheds where
salmon and Steelhead once thrived. These urban creeks often pose differ-
ent restoration challenges.
Creek restoration has been occurring around the Bay Area for decades.
Local waterways tend to be smaller in scale, and their banks are more ac-
cessible than mudflats or marshes, making them prime candidates for re-
juvenation by volunteers with strong backs. Some form of restoration has
been done on about half of the bay's named creeks over the last 40 years.
This work has taken many forms, such as clearing trash from channels,
removing small dams, and ripping out invasive ivy coating banks. To
strengthen crumbling creek banks, people have bundled willow and other
vegetation into living walls, and reshaped stream channels and floodplains
to restore their ecological function. More than 50 creek groups are active
in the East Bay alone. A few have been responsible for sparking interest in
creek restoration not just in the Bay Area but across the country.
The “watershed moment” of creek restoration occurred at Berkeley's
Strawberry Creek. In the early 1980s, creek activist Carole Schemmerling,
Berkeley parks architect Doug Wolfe, members of the nonprofit Urban
Ecology, and others exhumed a stream buried beneath an old rail yard in
central Berkeley, then turned the area into a park. They dug up the culvert
encasing the creek, smashing the concrete pipe with sledgehammers. The
darker soil saturated by groundwater meandering along the old stream
channel helped activists re-create the original creek meanders.
