Lake Ontario Annual Spring Prey Fish Survey Collects Record Number of Trawls

Release Date:

USGS - NYDEC Collaboration Produces Record Results

Retrieving a Bottom Trawl

Retrieving a Bottom Trawl Net on the Great Lakes

(Credit: Andrea Miehls, USGS - GLSC. Public domain.)

During April 2019, USGS scientists teamed with scientists from the New York State Department of Environmental Conservation, Ontario Ministry of Natural Resources and Forestry, and US Fish and Wildlife Service to collect 251 bottom trawls for the Lake Ontario annual spring prey fish survey. Prey fish assessments from this survey are a primary information source used to manage Lake Ontario. Catches of Alewife, the dominant prey fish, were generally lower than previous years but a single, near-record catch of 736 kilograms (1620lb) illustrated an increasingly patchy distribution. Experimental trawling in previously-unsampled embayment habitats found increased prey fish diversity and more native species relative to main-lake habitats. Embayment sampling also measures spawning success of native coregonines like Cisco and Lake Whitefish which are species of management interest in Lake Ontario and throughout the Great Lakes.