Adult crayfish (rusty and virile) trapped in Sparkling Lake between 2001 and 2010.
Sparkling Lake Crayfish capture Data
Adult rusty crayfish were trapped in August of 2001 and from June-August of 2002-2011 using Gee-style minnow traps modified by widening the openings and baited with beef liver or frozen fish following (Capelli and Magnuson 1983). Between 30-313 (mean=149) traps were set at 43 sites around the perimeter of the lake at the 1 m depth contour, with higher concentrations of traps in locations of higher crayfish abundance (Hein et al. 2007). Traps were emptied daily from 2001-2003 and every 1-4 days from 2004-2011 as catch rates declined. From 2001-2008 all trapped rusty crayfish were removed, and all native virile crayfish (Orconectes virilis) were released. From 2009-2011 trapping continued but all crayfish were released. Catch per unit effort (CPUE) of each crayfish species is used as an index of adult crayfish abundance, and was calculated daily (total crayfish caught/total trap days).
Capelli G.M. & Magnuson J.J. (1983) Morphoedaphic and Biogeographic Analysis of Crayfish Distribution in Northern Wisconsin. J. Crustacean Biol., 3, 548-564
Hein C.L., Vander Zanden M.J. and Magnuson J.J. (2007) Intensive trapping and increased fish predation cause massive population decline of an invasive crayfish. Freshwater Biol., 52, 1134-1146