By STEVE URIE
At the 2011 Aquatic Invasive Species Forum, Tahoe Environmental Research Director Geoffrey Schladow reported that a test of suffocating Asian clams under rubber mats achieved 100 percent mortality in 28 days, and that the cost to kill the clams was 100 clams per penny. Three years later, 35 tons of rubber mats that were spread over the floor of Emerald Bay for two years are being rolled up and put into storage.
The $900,000 Emerald Bay project killed 90 percent of the clams, which the Tahoe Regional Planning Agency said populated the bay in densities of 10 to 300 per square meter. That’s an astounding 25 cents to kill each clam — or 2,500 times the cost per clam that Schladow had projected.
When the Emerald Bay project started, Schladow declared it a “scientific success” and said it would be a complete success when a sustainable control program was in place. Nine months after the rubber mats were rolled out, Schladow and three other researchers concluded in an obscure $264,000 U.S. Forest Service study: “A hypothetical 100-acre area for [clam] treatment indicates that total costs of treatment can range [up] to $26 million.”
The report to the Forest Service says that rubber mats “will neither achieve eradication, nor the maintenance of low density populations of Asian clams in Lake Tahoe.” Clearly, suffocating Tahoe’s Asian clams wasn’t a scientific success and isn’t sustainable. And even though tests five years ago showed the suffocation method was the most efficient and least environmentally destructive way to eradicate Asian clams, researchers are now recommending new experimental methods, and TRPA is investigating using electric rakes and bottom-scraping machines to control the benign crustaceans.
At last summer’s Tahoe Summit, Schladow glossed over his failures and boasted to the politicians and environmental stewards that 90 percent of the clams under the mats had been killed. He neglected to tell the 400 dignitaries and contributors that at least a dozen native species had been decimated along with the non-native clams, and that the clams would repopulate Emerald Bay in about the same time as it took to suffocate them.
Schladow also forgot that he told the Forest Service that the rubber mat method didn’t work and was cost prohibitive. An October Capital Public Radio story reported that TRPA is searching for funding for a full-scale Asian clam eradication project, and TRPA Director Joanne Marchetta says that the aquatic invasive species control program is one of the reasons TRPA is asking Congress for $415 million dollars. There are many worthwhile projects that are dependent upon passage of a Congressional act, but killing Asian clams isn’t one of them.
~ Steve Urie is the author of Tessie, Quagga Mussels, and Other Lake Tahoe Myths. To learn more about Tahoe’s AIS programs, and to sign a petition that asks that before more aquatic animals are killed TRPA performs an independent aquatic invasive species risk assessment, go to savetessie.org.
