Dataset: Cod by-catch reducing gear: fishing log from Fishing Vessels NEC-MP2000-2 in the Gulf of Maine from 2000-2002 (NEC-CoopRes project)

"Groundfish Trawl nets Designed to Reduce the Bycatch of Cod": Fishing log of experimental tows included in analysis.

Project Leader:Michael Pol Massachusetts Division of Marine Fisheries

final report

Two experimental trawl net designs substantially reduced catch rates of Atlantic cod Gadus morhua while allowing the targeting of flatfish Pleuronectidae, as compared to a standard net design. The "Ribas" and "topless" nets both modify the top half of a trawl net; the Ribas net by using large square mesh; the topless net by removing much of the netting in the top square of the net. Seventy pairs of alternate tows showed reductions of cod catch rates (kg/hr) that exceeded 76% for both nets. Catch rates of yellowtail flounder Limanda ferruginea below MLS (~33 cm TL) were more than 74% lower for both nets, compared to a standard flatfish trawl. Reductions of catch rates for winter flounder Pseudopleuronectes americanus below MLS (~33 cm TL) exceeded 61%. Significant reductions occurred in catch above MLS for yellowtail (>32%) and winter flounders (>44%) with some evidence that this reduction was lower for the topless trawl. Underwater video showed cod exiting the nets through the top mesh and through the gap made by the removal of twine. These results demonstrate that separation of Atlantic cod from flatfish is possible and practical. (from final report abstract)

associated datasets:
Cod by-catch reducing gear: video observations of fish behavior