Welcome to the interactive web schedule for the 2017 SEAFWA Conference! For tips on how to navigate this site, visit the "Helpful Info" section. To return to the SEAFWA website, go to: www.seafwa.org/conference/overview
Note: Session titles beginning with an asterisk (*) have student presenters.
AUTHORS: Corbin D. Hilling, Yan Jiao - Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University; Aaron J. Bunch, Robert S. Greenlee - Virginia Department of Game and Inland Fisheries; Donald J. Orth, Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University
ABSTRACT: Blue Catfish were introduced to the tidal rivers of Virginia in the 1970s and 1980s. As these populations have matured, Blue Catfish have expanded to new river systems and now make up a considerable proportion of the biomass in several rivers. Incredible abundances coupled with misconceptions about feeding habits of Blue Catfish have generated concern for imperiled and economically important species within the Chesapeake Bay watershed. Further, the species provides recreational and commercial fisheries, generating conflict in the region surrounding the species. To support development of management strategy development and robust stock assessments, we estimated total and natural mortality, as well as size structure for four tidal river systems (James, Mattaponi, Pamunkey and Rappahannock). Total mortality from the period 2002-2016 was estimated using catch-curve regression, while published empirical estimators provided estimates of natural mortality. Data from the period were pooled to lessen the influence of variations in recruitment on mortality estimates. We used proportional size distributions to examine changes in size structure over time. The proportion of large blue catfish increased and peaked at different times among rivers likely due to differences in stocking histories and productivity. Recent declines in proportion of memorable and trophy size fish appears more dependent on growth declines than mortality. This study provides mortality estimates for the development of stock assessment models and management strategy evaluations. Further, understanding the size structure of these populations will help resource managers gauge the prevalence of large fish, providing feedback on angling opportunities and size-based trophic interactions.
Tuesday October 31, 2017 8:20am - 8:40am EDT
French