Asian Clam Sampling on the Missouri River Downstream of the Big Bend Dam in Lake Francis Case, South Dakota

摘要

The Asian clam, Corbicula fluminea, is an aquatic nuisance species that was collected downstream of Fort Randall and Gavins Point dams in 2005 and 2006 (Grohs 2008), and downstream of Gavins Point Dam throughout the 59-mile reach in 2004 (Shearer et al. 2005), 2007 and 2008 (Stukel et al. 2008; Stukel et al. 2009). In 2009 Asian clams were found in the summer rearing ponds at the Gavins Point National Fish Hatchery (NFH) in Yankton South Dakota (Schilling et al. 2010). This is a concern for the paddlefish (Polyodon spathula) propagation program, initiated in 1972 to maintain an exploitable population, because paddlefish are an important fish to the Missouri River and the public. Paddlefish produced at Gavins Point NFH have been stocked annually from 1991- 2007 in Lake Francis Case (Sloss et al. 2009). Due to the risk of spreading Asian clams, stocking fish upstream of Fort Randall Dam has been temporarily postponed until evaluation of upstream waters determines the presence of an established Asian clam population. Therefore, Lake Francis Case was sampled for Asian clams from April 27th to May 8th 2010 to determine the presence or absence of Asian clams in those sections of the Missouri River where paddlefish have previously been stocked.