91AV

91AV marine biologist James Sulikowski, Ph.D., is the co-investigator for a $1,092,642 NOAA grant "Evaluating the Condition and Discard Mortality of Skates Following Capture and Handling in the Sea Scallop Dredge Fishery."

Background

One of the most significant issues affecting marine fisheries management is the immediate and delayed mortality of fish that are discarded (as bycatch) after capture. 

Although the global discard rates of skates have been increasing since the 1970's, only a few studies have investigated bycatch mortality rates in this cartilaginous group of fishes. In the western North Atlantic, there is a continued need in management circles for skate discard mortality data, particularly in fisheries where skate discard rates are high.  

There are five species of skates found within Gulf of Maine/Georges Bank that are subjected to various commercial fishing activities: the barndoor (Dipturus laevis), thorny (Amblyraja radiata), winter (Leucoraja ocellata), smooth (Malacoraja senta), and little (Leucoraja erinacea) skates.

Previous research from 2009-2011 on skate bycatch in the otter trawl fishery by Sulikowski and John Mandelman, Ph.D., research scientist at the New England Aquarium, suggested that discarded winter and little skates were more resilient than expected to this form of fishing pressure.

That otter trawl research contributed to a November 2011 emergency action by the National Oceanic and Atmospheric Administration (NOAA) to revise an existing policy and increase the amount of skate that fishermen could land that year.

So far the results of that research have resulted in a 56 percent increase in the amount of skates that fishermen can land and an estimated $5 million per year increase in profits for skate fishing industry.

Current Research

The scallop dredge fishery is second only to otter trawl for the distinction of highest skate discard rate by gear type. However, despite a lofty annual catch biomass of prohibited (barndoor, and to a lesser extent thorny skate) and non-prohibited (winter and little skate) species, skate discard mortality rates in this fishery have yet to be evaluated in U.S. waters.

Thus, this new two-year collaborative study aims to determine the mortality rates of the aforementioned species and to identify those factors most influential on skate survival by species. It is being conducted out on Georges Bank in collaboration with the scallop fishery and will run through July 2014.

Funded by NOAA's Sea Scallop Research Set Aside Program for $1,092,642, Sulikowski, an associate professor in 91AV Department of Marine Sciences, is collaborating with David Rudders, Ph.D., of the Virginia Institute of Marine Science, and Mandelman, from the New England Aquarium, on this project.