On Nov. 4, 2004, researchers at Rensselaer Polytechnic Institute’s Darrin Fresh Water Institute (DFWI) found three settled juvenile zebra mussels on plates that were removed from the Ticonderoga Boat Launch Site.

Zebra mussels—a non-indigenous species that are not present in the historic record of an area—have been a major concern in recent years. Considered a prolific nuisance, they grow in clusters that wreak havoc on the water intake pipes of water treatment facilities, power plants and industry.

Since 1997, the DFWI has maintained zebra mussel “spat traps” at four to six locations in Lake George, which currently include Ticonderoga Boat Launch, Coates Point, Dark Bay , Green Island , and King Neptune’s. Spat traps are recruitment collectors containing eight stainless steel plates. Each spring and fall the plates are exchanged from the traps and examined for the presence of settled juvenile mussels.

Until last week, no settled juvenile mussels had been found on any of the plates since collection began in 1997. On November 4, 2004, three settled juvenile zebra mussels were found on the plates that were removed from the Ticonderoga Boat Launch Site.

The sizes of the mussels removed from these plates were 8.4, 9.4, and 10.6 mm in length. Clean plates had been installed at this location on May 28, 2004, so the juvenile mussels are no more than 5 months old.

"Although there are a number of factors indicating that Lake George provides a less than favorable environment for zebra mussel colonization, this new discovery of juvenile zebra mussels at the Ticonderoga Boat Launch site raises concern. If steps are not taken to prevent the continual introduction of zebra mussels into the lake, it is possible that Lake George will eventually become colonized by this invasive species," said Sandra Nierzwicki-Bauer, Director of the DFWI and professor of biology.

Nierzwicki-Bauer highlighted steps that can be taken to better protect Lake George from zebra mussel colonization:

• People should be on the lookout for zebra mussels, including inspection of docks when removed from the lake. If a zebra mussel is discovered, it should be removed, placed in a plastic bag and brought to the Darrin Fresh Water Institute (DFWI) in Bolton Landing or call DFWI at (518) 644-3451.
• People should not take water or bait taken from one lake and use it in another.
• Require inspection and cleaning of vessels prior to launching into Lake George.

Published November 12, 2004