Pick your poison

At Plumas County’s Lake Davis, about 150 miles upstream from Sacramento, the verdict is in: The population of northern pike, a large, non-native fish, has gotten way out of hand. The mouthy predators have eaten up far more than their share of the lake’s coveted rainbow trout, and biologists and fishermen statewide fear that if the pike are not eradicated soon, they somehow will escape the lake, spread through the Sacramento River system and ultimately devour California’s multimillion-dollar Chinook salmon and steelhead fisheries.

“In the Sacramento Valley and Delta waters, there is a lot of slow backwater habitat that pike would really enjoy,” said Peter Moyle, professor of fisheries at UC Davis. “The pike fits into the category of an animal that’s going to do some real harm if it gets loose. It’s a top predator. Small salmon smolts in the Sacramento [River] won’t know how to react to this new style of predation. Maybe they could learn in two or three thousand years, but I don’t think we have that kind of time.”

While the Lake Davis trout population continues to decline as the pike take over, the Department of Fish and Game and the U.S. Forest Service currently are reviewing plans for a full-throttle pike-eradication effort to be carried out late in the summer of 2007. If they move ahead with it, government biologists will lower the lake level to concentrate its waters and will proceed to deploy lethal doses of the chemical “piscicide” rotenone—again.

Remember? A similar plan of action in October of 1997 failed, and the controversial chemical treatment only created a storm of sensational media coverage, anger, hurt feelings and dead fish. The pike were gone for a while—as were the lake’s beloved trout. But in 1999, the big, snaky fish reappeared.

“The failure probably occurred in tributary streams above the lake,” said Mike Morrison, fisheries biologist with DFG’s Portola office. “There are some braided, willowed channels where the rotenone may not have mixed, but we’ve now identified those places where the pike could have survived.”

Rotenone deteriorates naturally in water, and within a month of the 1997 treatment the chemical mostly was gone and Lake Davis was perfectly livable again. The DFG restocked the lake with hatchery trout, making anglers happy. But without yet knowing it, the government also was feeding the surviving population of pike.

When the stubborn invaders were rediscovered in 1999, the frustrated DFG began to survey and sample the lake extensively, using nets and “electro-fishing” techniques. Once a month, they toured the shoreline in a government skiff while emitting a 120-volt, eight-amp pulse of electricity into the water and netting the stunned fish that floated to the surface. Between 2000 and 2004, according to Morrison, the DFG’s rainbow-trout catch rate declined from 14.8 fish per “pulse-hour” to less than one. Meanwhile, in a brilliant textbook example of negative correlation, pike hauls increased from just one per hour of electric pulsing to 16.6.

Northern pike, which may grow to more than 5-feet long and over 60 pounds, first appeared in Lake Davis in 1994. The prevailing suspicion among locals is that someone placed them there intentionally, thinking that the community would like the opportunity to catch a few pike. But the voracious eaters have only spawned grief and headaches. To prevent the pike from escaping downstream via the outflow of the Grizzly Valley Dam, the Department of Water Resources installed a pike-screening system in 1996. Recently modified, the barrier is arranged such that nasty metal grates filter all water exiting the dam and pulp any fish that come flowing out of the lake.

But that does not fully contain the problem, for pike could still hitch a ride in an angler’s bucket or cooler to another lake or stream. To discourage such illegal transport—which can result in jail time and a $50,000 fine—DFG officers regularly patrol the reservoir and inspect the creels of fishermen as they leave the lake’s vicinity. Yet fear that the pike will escape remains strong. The big fish occur naturally across the northern hemisphere, from the British Isles to New England, but they have colonized many watersheds in the lower 48 states thanks to “bucket biologists.”

“In all cases,” Morrison said, “the pike have negatively affected the previously existing fisheries, and we expect they’d do the same to the Sacramento River.”

While the DFG’s eradication efforts met great resistance in 1997 as officials went about prepping Lake Davis for its rotenone treatment, this time things are quite different in the small town of Portola, seven miles from the lakeshore. Bill Powers, formerly Portola’s mayor and currently the head of the Lake Davis Steering Committee, was vehemently opposed to the pike-eradication plan in 1997. Powers recalls the night before the rotenone treatment. Tensions were high after months of friction between the community and the DFG. While a throng of last-minute demonstrators marched against the government, Powers and three other people quietly slipped away from the crowd, donned wet suits, entered the lake at dawn and swam out to a buoy, to which they chained themselves in protest. The onset of hypothermia eventually forced Powers and his comrades back to shore, where they were arrested, and the lake’s treatment began promptly thereafter.

Ten years later, however, Powers fully supports the DFG’s plan.

“They were belligerent and uncooperative last time,” he said. “We all wanted to know how the chemical would affect our water, and all they said was, ‘You’ll just have to trust us.’ This time they’ve really tried to communicate and work with us, rather than bully past us, and most people now agree that the pike have to go.”

Jerry Dollard of Dollard’s Sierra Market reported that many other town residents who adamantly opposed the pike-elimination plan a decade ago have come to accept the effort.

“We’ve had a lot of meetings with the DFG and there’s been a lot of science and education to quell the fears about the chemicals,” he said. “It’s my opinion that most of us have come to realize that we have a problem that merits whatever inconveniences will come along as we try to correct it. It’s like cancer and chemotherapy: It’s not pleasant, but it has to be done.”

Fran Roudebush, head of the Lake Davis Coalition, a loosely-knit group of several dozen concerned local citizens, does not agree with the supposition that the community is eager for the autumn dousing.

“I don’t think people have changed their minds or their opinions about the treatment plans. They’ve just quieted down because they think it’s futile to resist the inevitable.”

Roudebush conceded that pike are a threat to fisheries statewide, yet she insists that the chemical-treatment plan is not necessary. As an alternative, she said she would like to see the DFG boost its electro-fishing efforts to keep the pike at bay.

But Dollard feels that there is no time to lose in managing the pike through non-chemical means.

“We’ve got a lot of those potential pike-Johnny Appleseeds around here, and I shudder to think of what’ll happen if someone moves the pike into the river. The longer you let a problem go, the more expensive it becomes to fix. If we don’t do something soon, then some dummy is going come along and bring the pike elsewhere.”

Such as nearby Lake Almanor, a fishing destination famous for its big trout and landlocked Chinook salmon, which perhaps could suffer deep economic grievances if colonized by pike.

“The people at Almanor are terrified that they’re next,” Morrison said.

While a small contingent of people opposes the pike-eradication movement, no one voices support for the pike and most anticipate the day when Lake Davis is at last a healthy trout lake again.

“It’s a necessary action,” Powers said. “This whole thing is a cloud that hangs over us and won’t go away. Pike lay a tremendous amount of eggs per pound of body weight and they’ve just taken over the fishery. I sure wish whoever put them there in the first place had never dreamed of such a thing.”