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Indicators of Pow-Wow

A "major shift in Bay-Delta scientific thinking" occurred at an October workshop where some fifty scientists gathered to discuss possible indicators of the Estuary's ecological health, according to Bill Alevizon of The Bay Institute. The workshop was jointly sponsored by the Institute, the UC Berkeley Center for Sustainable Resource Development and the Environmental Defense Fund.

Alevizon says that to assess the system's well-being, scientists have historically relied on population-level indicators like species abundance - indicators that in themselves are "not enough." Alevizon says, "There was broad consensus at the workshop that we also need to develop habitat-, community-, ecosystem- and even landscape-level indicators. So in addition to counting clapper rails, for example, we'll look at flow regimes and sedimentation rates for wetlands - the processes that allow the ecosystem to produce and evolve naturally."

The scientists came up with an initial list of roughly 40 indicators based on such factors as hydrology, key natural habitats and water quality, but the debate over what the list should include continues. "If we base indicators on distant history or primeval California, we won't get anywhere," says U.S. EPA's Bruce Herbold. "There have been too many introduced species; too many irreversible changes."

"It's difficult to select gauges when there is so much we don't know and so many variables all acting on each other in the Estuary," says Water Resources' Leo Winternitz.

"Ecosystem management may be motherhood and apple pie right now," says consultant John Williams, "but I feel strongly that we're not going to find a small set of indicators that tell us if we're where we want to be."

The scientists will reconvene in late January to refine their list and attempt to begin the process of establishing target levels for the indicators. Alevizon says such indicators are "integral" to determining appropriate restoration goals and believes they will in turn guide the CALFED Bay- Delta program, the Wetlands Ecosystem Goals Project and other long-term planning efforts that promise to influence the Estuary's future.

Contact: Bill Alevizon (415)721-7680

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