Biology Reference
In-Depth Information
AS PART OF AN ESTUARY
, the bay's health is inextricably connected to the
health of its watershed. Everything that happens on the lands upstream,
and on the banks of the rivers and creeks flowing into the bay, affects the
quality of its waters and quantity of its salmon, waterfowl, and other wild-
life. The rivers and streams of the watershed connect inland California to
the coast, and the bay to 40 percent of the state.
“In the last 20 years, one of the best things we've done from an ecologi-
cal perspective is recognize the value of landscape-level restoration, such
as restoring flows to a dewatered section of the San Joaquin River, and re-
introducing tides to the South Bay salt ponds,” says Tina Swanson, who
once ran The Bay Institute. The institute was one of the first groups to
make the case that the health of the bay was dependent on the health of its
watershed. “Unlike smaller projects, which mostly provide locally isolated
refugia, the scales of these projects reconnect habitats across the water-
shed landscape and restore ecological function,” says Swanson.
Central Valley wetlands. (Department of Water Resources)
Restoring ecological function is the best that can be done in a water-
shed as built-up and replumbed as that of the San Francisco Bay Estuary.
The idea of “restoration”—humans returning a degraded landscape to
some more pristine historic state—is inspirational but romantic. What
people are really doing is not restoration but “renaturalization,” according
to Stanford hydrologist David Freyberg. He says natural systems aren't
fixed—especially not highly variable estuarine systems—so restoration
targets are indistinct at best. At most we can reintroduce more natural
flow patterns in the watershed, and then monitor whether these changes
result in healthier species.
