TRPA: Clam suffocation at Emerald Bay successful
Mats in Emerald Bay as seen from the air. Photo/LTN file
It may take until the end of November for divers to remove the 5 acres of rubber mats that were laid on the lake bottom at the mouth of Emerald Bay.
This was done two years ago as a pilot project to control Asian clam populations in the area. The mats measure 10-feet-by-100-feet and weigh 300 pounds.
Boaters are asked to exercise caution when entering and exiting Emerald Bay and obey a no-wake zone that extends 600 feet from shore.
The mats were used to smother and kill the nonnative Asian clams by starving them of oxygen. Early sampling indicates at least a 90 percent mortality rate in the treated area, according to Tahoe Regional Planning Agency officials.
Asian clams can stimulate algae growth, displace a variety of native species, and increase the potential for other invasive species such as quagga mussels to establish in Lake Tahoe by increasing calcium concentrations in the water.
— Lake Tahoe News staff report
What If we were to inject Co2 into the top 6 inches of sand in the lake bed. This may make a Ice covering over the breeding grounds or flash freeze them. The Co2 may slowly melt and evaporate to the lake surface. I’m not a Scientist or Biologist so I’m asking those who are, “would this work to save our Lake?”.
Freezing point of CO2 is around -108 degrees (F)… it doesn’t seem like it would be frozen for very long.
Noting that CO2 is a ‘mode’ of fire extinguisher – (it hits the air as a ‘frosty blast’ in putting out a fire), it may well quickly absorb the oxygen needed (it smothers a fire), but I would worry about the oxidation of the lake (as the acidification of the ocean) but the key, if tried, would be “in moderation” given that there are trillions of gallons of water in Tahoe. . .
As CO 2 in the circumstance you mention would most likely end up as ‘sequestration’ (carbon storage), it may merit mention. . .I’m a Board Member of the Tahoe Conservation District, which undertakes that work, so I will mention Sean’s suggestion, especially the ‘underneath’ part. . .
At least someone’s thinking about it. . .
Thank you for that. . .
Do you really think it took 2 years to deprive the clampets of oxygen to kill them ?
All about the money/funding to remove the tarps.
The same method was used at ski run Marina outer channel , but tarps only left down for a few months.
At both locations tarps worked loose from the bottom, creating a hazard to safe navigation of these areas.
The M S Dixie actually became entangled in loose tarps at E bay last year.
Killing the clams does not remove the source of calcium , and seeing as they are all dead in E bay channel I would guess an even higher level of calcium in the works.
Is the channel at E Bay to be dredged and the shells filtered out ??
The science project continues.
Have you seen the results of non-chemical treatment to remove quagga mussels from this Minnesota Lake? They claim 100% mortality with no adverse effects on swimmers/pets/other aquatic life. Would this work on clams at Tahoe? Almost seems too good to be true, but worthy looking into.
http://www.marronebioinnovations.com/2014/09/zequanox-achieves-100-mortality-for-invasive-mussels-in-minnesota-lake/