July 20, 2012

Capitol Campus Update

A scientist with EnviroScience, Inc., an environmental consulting firm, will be on Capitol Lake and the adjacent East Mitigation Pond on July 24 conducting a follow-up population survey of weevils that eat Eurasian milfoil, an invasive aquatic weed.

The state had about 12,000 weevils (Euhrychiopsis lecontei) intentionally released into the four-acre East Mitigation Pond in August 2009 as an experiment to determine if the bug can help control milfoil, which was discovered in the lake in 2001.

Milfoil grows quickly crowding out native plants and degrades water quality. It is almost impossible to eradicate once established.

The former Department of General Administration, which is now part of Enterprise Services, treated the lake with an herbicide in 2004, killing off most but not all of the milfoil. Since then, Enterprise Services has controlled the milfoil infestation by hand-pulling the weed. The department is trying to determine if weevils can be used as another effective non-chemical weed control tool.

The scientist will survey the weevil population in the pond and check to see if the bugs have spread into the southern end of Capitol Lake. The project is funded through a grant from the Department of Ecology.