Fear and loathing in Lake Davis

On Monday the state of California started dumping $16 million and 17,000 gallons of poison into Lake Davis, all in the name of environmentalism. According to a New York Times article, 500 state fish and game personnel will be pouring CFT Legumine, which contains the poison rotenone, into Lake Davis in an effort to eradicate northern pike, an exotic invasive fish.

The northern pike is certainly an easy animal to fear. The aggressive invader with the folk name "water wolf" can grow more than three feet long and eats whatever it can get its razor sharp teeth around, like frogs, bugs, other fish, and even the occasional duckling. According to the NYT article, "State officials are particularly concerned that the pike might escape to the Sacramento-San Joaquin Delta, where it could feast on other fish, including valuable salmon and threatened species like the delta smelt. Signs on the lake recommend cutting the head off any pike caught and tossing the fish back in the water."

The pike first appeared in Lake Davis in the mid-1990s and were very likely introduced by people. In 1997 officials poisoned the lake with rotenone to the point that the state approved a $9.2 million settlement with local residents for damages. But the pike reappeared in 1999. Nobody's sure how many pike currently live in Lake Davis, but the California State Department of Game and Fish estimates the population could number in the tens or hundreds of thousands.

Ok, so the pike breeds and hunts aggressively and isn't the cutest fish in the lake. But, is it worth pouring into Lake Davis a pesticide the World Health Organization classifies as "highly toxic for aquatic life" and, in its pure form, as "moderately toxic" to humans?

The State of California has successfully eradicated northern pike from the nearby Frenchman Reservoir by using rotenone. According to an info sheet on the Department of Fish and Game site:

[Rotenone] will be applied at a rate of about one part per million. The rotenone itself will initially be present at a rate of about 50 parts per billion. The trace compounds will be present at a few parts per billion at the greatest, and many will not be detectable in the water when the rotenone is applied.

Rotenone also decomposes quickly and there are no detectable traces of rotenone left in Lake Davis from the 1997 treatment. The lake, which does not currently supply the nearby town of Portola with water, will be closed for up to 45 days after treatments this month. The lake will again serve as the water supply for Portola at some point in the future.

Researchers at Emory University found that when they gave rats low doses of rotenone, the rats developed symptoms similar to symptoms found in people with Parkinson's disease. The findings "are consistent with the idea that chronic exposure to low levels of environmental toxin may cause cumulative damage to the brain’s dopamine system, eventually leading to the clinical symptoms of the disease."

While rotenone is being used in very low concentrations and decomposes quickly enough that it's not at risk of causing chronic exposure on its own, it is one more environmental toxin that we're exposed to. So, the risks the rotenone in Lake Davis could pose to human health are not clear.

And what about the plants and animals in and around Lake Davis, for which rotenone is "extremely toxic"? The website for the Department of Fish and Game says they will "herd" the trout downstream and restock them after the treatment, but they make no mention of the other species that inhabit the lake and happen not to be as important to the economy as trout.

But, wait. CFT Legumine, which the Department of Fish and Game will be using to apply the rotenone, actually only contains five percent rotenone. According to the manufacturer site, CFT Legumine also contains five percent "other associated resins" and 90 percent "inert ingredients". On savelakedavis.org Jeanne Tansey writes:

In the case of CFT Legumine™, the inert ingredients help disperse the pesticide more easily and evenly into the water.

16,000 gallons of CFT Legumine™ is the projected amount of poison according to the Lake Davis Northern Pike Eradication Project 2007 plan. That means that 90% or 14,400 gallons of inert ingredients will be put into the lake. We do not know exactly what those ingredients are. But the front panel of the pesticide container, immediately below the Ingredient Statement, reads “Contains aromatic hydrocarbons.”

The Department of Fish and Game doesn’t even know what the 90% inert ingredients are. They do not know what the 14,400 gallons of liquid chemicals, that they will be putting into the lake and surrounding streams, are. They analyzed a sample of CFT Legumine™ to get an idea of what they might be. We do know what chemicals the health agencies will be testing Lake Davis water and sediment for after the lake is poisoned. Page 7 of the Lake Davis Northern Pike Eradication Project 2007 plan is the “Water Quality Monitoring Plan.” It contains a list of 18 chemicals they will be monitoring in surfacewater and sediment. A logical conclusion would be that these chemicals were found in their analyzed sample.

Among these chemicals are benzenes, xylenes, naphthalene, and toluene. The U.S. Department of Health and Human Services includes naphthalene, toluene, and xylenes on its “Table 1, Hazardous Inerts.” Table 1 is the list of the most dangerous chemicals identified by the Dept. of Health and Human Services. . . Benzene exposure also causes serious health effects.

So, the Department of Fish and Game doesn't even know what's in 14,000 gallons of the stuff they're dumping into the lake? Northern pike might be bad for the ecosystem (or maybe more accurately, the fishing economy) in Lake Davis. CFT Legumine might be even worse.