NEW THIS YEAR! The schedule of technical sessions is in Sched.org which allows you to search within the schedule, filter the schedule to show sessions only occurring on a certain date, within a track, or in a room. You can also build your own schedule by creating a free account in Sched.org. Click here to return to the main Midwest Fish & Wildlife Conference website. 

PLEASE NOTE: The schedule posted here is as of 1/25/16, and is subject to change. Please check back for updates.
Back To Schedule
Tuesday, January 26 • 1:40pm - 2:00pm
Zooplankton Density and Community Composition Shape Success of Fry-Stocked Sander Spp.

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

AUTHORS: Joseph D. Conroy, Ohio Department of Natural Resources; Richard D. Zweifel, Ohio Department of Natural Resources

ABSTRACT: Many factors affect annual success of stocked Sander spp. (both walleye Sander vitreus and saugeye, Sander vitreus ♀ × Sauger S. canadensis ♂). In Ohio, Sander spp. have traditionally been stocked as fingerlings (about 6-week old, 25-mm total length juveniles) but a research project in three tributary reservoirs showed that fry (6-day old, 7-mm) successfully produced cohorts of comparable strength to fingerling stocking when densities of crustacean zooplankton were sufficient. Here we expand this previous research to additional tributary reservoirs (n = 7) and two additional reservoir types (canal, n = 2; upground, n = 11) during the period 2011–2015. We determined zooplankton density and community composition at the time of fry stocking and one week post-stocking. We then directly compared fry stocking success (defined as fall age-0 catch per hour of standardized electrofishing) with zooplankton densities (#/L) concurrent to stocking and used multivariate statistical methods to explore how stocking success related to crustacean zooplankton community composition. Stocking success varied from 0 to nearly 1,000 age-0 Sander spp./ha while crustacean zooplankton densities ranged 72–3,601 zooplankters/L. Although fry stocking success and zooplankton density were not directly correlated, stronger year classes often corresponded with crustacean zooplankton communities composed of mostly calanoid copepods and cladocerans. Consequently, knowing patterns of zooplankton community composition may better identify reservoirs in which fry-stocked Sander spp. do well.

Tuesday January 26, 2016 1:40pm - 2:00pm EST