The Survival of Rajids Discarded in the New England Scallop Dredge Fisheries

Wednesday, September 11, 2013: 11:20 AM
Conway (The Marriott Little Rock)
Ryan Knotek , Marine Biology, University of New England, Biddeford, ME
John Mandelman , Edgerton Research Laboratory, New England Aquarium, Boston, MA
David Rudders , Marine Advisory Services, Virginia Institute of Marine Science (College of William and Mary), Gloucester Point, VA
Hugues Benoit , Gulf Fisheries Centre, Fisheries and Oceans Canada, Moncton, NB, Canada
James Sulikowski , Marine Science Department, University of New England, Biddeford, ME
Due primarily to regulatory factors, skates from the family Rajidae account for nearly half the total bycatch discarded during commercial fishing operations in the U.S. portion of the Northwest Atlantic Ocean. However, despite the rigors of capture and handling, and mounting management and conservation concerns, few studies have investigated the post capture viability/condition or short-term (delayed) mortality among skates in this region. The only study to date, conducted on otter trawl captured species, suggested a high degree of species-specific tolerance to capture by this gear type. Although the New England scallop dredge fishery has the second highest skate discard rate, no information regarding the resiliency of skates to interaction with this gear type exists. Thus, this study aims to investigate the species-specific immediate and post-release mortality rates for little (Leucoraja erinacea), winter (Leucoraja ocellata), and barndoor (Dipturus laevis) skates. Mortality rates will be quantified using the combination of mortality predictors (i.e. condition and reflex impairment) and 48-hour mortality trials in an on-deck tank system. In addition, this study will assess the effect of factors such as fishing conditions (e.g. season and depth) and practices (e.g. tow times, volume of catch, deck duration) on post-release mortality.