Update April, 2009:
Mass DCR confirmed identification as Asian Clam, a new infestation localized at the state boat ramp. 14 Massachusetts lakes have been identified as having Asian Clam. Correct timing of the winter drawdown of the waterlevel can be employed as a successful, no-cost method of control for this young infestation of the exotic, non-native invasive species.
Posted March 30, 2009.
Upon further investigation, hundreds, perhaps thousands, of tiny empty shells appeared on the shore and in the shallow water aside of the launch area at the State Boat Ramp on Torrey Road, Sutton. Photos below, taken March 20 and 22, 2009, show teeny tiny shells – open and empty.
Perhaps Asian Clam (Corbicula fluminca)- Since we have not encountered before, clearly not the larger native mussel common to Manchaug Pond, and the location found is the state boat ramp strongly suggest it was brought in from a visiting boat from another lake which has the exotic invasive species.
The Massachusetts Department of Conservation and Recreation Lakes and Ponds’ Weed Watchers Program had been contacted to get a positive identification and to set up training for members on exotic invasive species.
The cause of death? Winter drawdown. 2008, last winter, the dam owner Interface Fabric deviated from the usual recommended timing of the winter waiting until the second week of December rather than the traditional September – October. This was documented in a written testimony submitted by the Manchaug Pond Association on September 16, 2008 to the Sutton Conservation Commission siting 2003 recommendations from Lee Lyman of Lycott Environmental for Manchaug Pond:
“Gradually begin mid-September to early October to ‘allow certain aquatic organisms such as fresh water mussels, crayfish, turtles and amphibians to migrate to deeper portions of the water body to over-winter.'”
This testimony was presented as Manchaug Pond is also home to native mussels, crayfish, turtles and amphibians… As Interface’s engineer Stantec points out in a March 4th letter to Sutton Conservation Commission concerning our gone and severely declined spring peeper and bullfrog populations in four cove areas, the same holds true with our mussel population and this clam species… “Stantec is not aware of any on-going studies or reports documenting amphibian populations around the reservoir. We are also not aware of any documented report from any local, state or federal agency linking a decline in amphibian populations to the lower water levels from this spring.”
If you notice anything out-of-the-ordinary, any adverse impact to the lake ecosystem, notify the Sutton and Douglas Conservation Commissions.
Further, the state Generic Environmental Impact Report can also be referenced for information on drawdowns: http://www.mass.gov/dcr/waterSupply/lakepond/geir.htm