Species compositions within hydroacoustic data are often partitioned using trawl catch data and there are several variations of these methods employed by different agencies throughout the Great Lakes.

The Great Lakes Fishery Commission recently funded a workshop directed at better integrating trawl catch data with hydroacoustic estimates of fish density.  The workshop was held in Sandusky, OH and hosted by subject experts Dan Yule, Tom Hrabik, Lars Rudstam, Dave Warner, Patrick Kocovsky, Randall Claramunt, Bernie Pientka, and Larry Witzel.

Three methods currently used on the Upper Great Lakes to integrate trawl catches with hydroacoustics were demonstrated and applied to common datasets and one simulated dataset.

Overall the methods returned similar estimates of species biomass under the condition that a sufficient number of trawl catches were available over a wide range of spatial coverage and depth strata.

The Service, represented by Dale Hanson (Green Bay FWCO) at this GLFC workshop, gained tremendous insight on application of trawl data and will implement workshop recommendations as the Spencer F. Baird’s hydroacoustic and trawling assessment program continues to develop.