Thursday, July 31, 2014
Asian Clam
Asian Clam

What is it?

Asian Clam was found in the fall of 2010 in the north end of Owasco Lake and it was been confirmed by the United States Geological Survey's (USGS) Nonindigenous Aquatic Species unit. Asian clam (Corbicula fluminea), otherwise known as "golden clam," is a non-native invasive species that is capable of rapid growth and spread. They are small bivalves (two shells hinged together), averaging less that 1.5 inches with an oval triangular shape. They are also known as the golden clam and they are yellow brown, light brown to black with distinctive elevated, evenly spaced concentric ridges on the surface. The Asian Clam prefers sandy or gravelly bottom areas, in shallow, warm water.

The Asian clam is hermaphroditic, which means you only need one to reproduce. A single clam can release over 400 offspring per day, depending on the conditions. In our climate, they typically spawn from July to September and have a life span of up to seven years. The juveniles do not swim but can easily be moved in water currents or transported by humans. 



Where is it from?

The Asian clam was first found in North America in 1938 in Washington State. It is thought that it was brought to the U.S. by immigrants as a food source. Since then, it has spread to over 40 states, most likely through the bait and aquarium trade. The juveniles can be moved in flowing water and could easily be moved around in bait buckets and other areas of a boat that holds water. Asian clams were found in several sections of the Susquehanna Basin as early as 1995, in Seneca Lake in 1999 at the power plant near Dresden, and in the Erie Canal near Utica in 2009. Exactly how the Asian clam was introduced to Owasco Lake or how long it has been here is unknown at this point.

Problems caused by Asian clam:

Two big problems Asian clams have caused in other water bodies are biofouling (or clogging of water intake pipes) and algae blooms. The clams filter feed on plankton and compete with native mollusks for food and space. While the potential impact of Asian clams becoming established in Owasco Lake is still unclear at this point, they can grow and spread rapidly, displacing native species, reducing biodiversity, and altering the food web. Some fish and crayfish do eat them, but at the densities they can reach, up to 500 clams per square foot, it is unlikely such predation would significantly affect their population. Nutrients from the excrement of the clam can feed plant and algal growth. In high densities, Asian clams have been associated with bright green algae blooms in Lake Tahoe.

What you can do:

We are asking lakeshore residents to see if Asian clam shells are washed up on their lakefront area and asking them to rake the sediment near and just below the waterline to see if they can find live Asian clams. If a clam is found in Owasco Lake that matches the description of the Asian clam, citizens are asked to get a sample or take a photograph and report it on the Owasco Lake Network website at www.owascolake.org. If you have questions about Asian clam in Owasco Lake, please contact the Owasco Lake Watershed Inspector at jreinhart@cayugaswcd.org. If you find one in a lake other than Owasco, please contact Amy Barra at Cayuga County Cornell Cooperative Extension at 315-255-1183.

Asian clams are spread by the adult clams being moved or the juveniles being moved in contaminated sediment or water taken from right above the sediment in areas where clams occur. To prevent the movement of Asian clam:
  • Do not move boats, bait, equipment, etc. from Owasco Lake to any other non-infested lake or stream. This is necessary to prevent their spread to Cayuga Lake, Skaneateles Lake, Duck Lake, Lake Como and other local waterbodies. If you must move it to non-infested waters, wash your boat and all equipment before leaving Owasco Lake (see further instructions below). Be sure to drain all water, including live wells and bait buckets. 

  • Do not use Asian Clams as bait.

  • Do not keep "golden clams" in outdoor water gardens.

  • Do not keep "golden clams" in your aquarium(s). If you already have them, do not empty water, gravel or any other aquarium contents near a stream or lake.


Additional boater information:

Many invasive species travel from waterbody to waterbody through boating. For boaters, when you leave any waterway you should:

  • Check and remove any visible mud, plants, fish or organisms from boats, trailers, equipment, clothing, dogs, etc. 

  • Clean and eliminate water from equipment.

  • Dry anything that comes into contact with water.

  • Never release plants, fish, or other animals into a waterway unless they came from that waterway.

More information can be found at: