Thursday, September 07, 2006

Lake Davis Pike

This sad story continues and appears endless.

An excerpt.


Second time time the cure?
Fighting pike in Lake Davis, Round II
- Published 7:27 pm PDT Wednesday, September 6, 2006


Lake Davis is an environmental time bomb. State officials -- once again -- hope to defuse it by poisoning the lake.

The cause of this drastic action is a non-native fish. Lake Davis contains northern pike, a fish that belongs in the Midwest and not in the Sierra. Pike are voracious predators. Were pike to somehow spill over the dam and make their way downstream into the Sacramento-San Joaquin Delta, they would threaten the existence of salmon and other native species.

The only physical solution, and it isn't a pleasant one, is to partially drain Lake Davis and to poison it with a variety of chemicals, including rotenone.

Such a proposal prompted outrage more than a decade ago when first advanced by state officials. Despite the protests, they went ahead and did it anyway. The poisoning in 1997 didn't kill every last pike, and now they dominate the lake once again.

That whole episode taught the state a tough lesson on how to approach a job this biologically tough and politically tricky. That lesson can be seen in the latest proposal.

First, the chemical attack: Next time (the poisoning is tentatively scheduled for fall 2007) the state will draw down the lake more than last time. That way, there is less water to poison and fewer pools, particularly upstream, where the pike can hide. A different chemical to spread the rotenone will be used, one that hopefully won't linger in the lake so long as last time. That lingering caused delays in reopening the lake and reusing it as a possible drinking water supply. (Since the last poisoning, local water officials have resorted to other sources.)

Second, community relations: This time around, both local and state governments seem to be communicating well and treating each other with respect. Skepticism about the whole notion of poisoning the lake led to strained relations the last time around. The state has very slowly approached this new proposal with an open process that has widespread support.