Temporal and spatial patterns in pelagic trawl fish catches in Lake Winnipeg

摘要: To better understand patterns of temporal and spatial variation fish assemblages in offshore waters Lake Winnipeg (Manitoba, Canada), midwater trawl tows were conducted near lakewide monitoring stations from 2002 to 2008. Trawl samples collected during spring, summer, fall the south basin, channel, north basin used study effects season geographic region within lake on species biomass estimates. Within each region, effect depth was explored. Greatest catches basin. Of most commonly caught species, across all seasons, greater emerald shiner (Notropis atherinoides) cisco (Coregonus artedi) found compared Biomass non-native rainbow smelt (Osmerus mordax), by contrast, or channel. Yellow perch (Perca flavescens) introduced white bass (Morone chrysops) varied temporally spatially, with greatest captured summer Estimated walleye (Sander vitreus) followed Patterns distribution probably are influenced a combination factors, including interactions differing temperature light conditions lake. As no pelagic studies have been reported for this lake, these data form baseline against which changes, such as trophic state establishment can be assessed.