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Ultra-Low-Opening Groundfish Trawl Development

The goal of this project is to develop a new, ultra-low-opening bottom trawl (ULOT) that minimizes the impact of trawling activity on the recovery of cod stocks to the greatest extent practicable and simultaneously enables fishermen to offset the impact of low cod abundance and remain operational and profitable. To achieve this goal, specific project objectives are to:

  • Develop and evaluate the ability of a new, low-opening bottom trawl to reduce catches of cod
  • Evaluate the ability of the low-opening bottom trawl to maintain catches of flounders, monkfish, and skates
  • Evaluate the effect of headline height and headline length on the geometry and catching performance of the low-opening trawl
  • Compare fuel consumption between the low-opening bottom trawl and a traditional trawl
  • Compare ease of handling between the two trawl types.

This project has adopted a highly systematic approach to the development of the ULOT, commencing with numerical testing using sophisticated modelling software followed by physical testing of a scale model in a flume tank. Following analysis of model data we constructed a full size ULOT for at sea testing. Preliminary analysis indicates we are on the right track, with cod catch rates reduced by approximately 40% with no loss of flatfish. Fuel consumption was reduced by just over 10%.

This project is a collaboration with scientists (Steve Eayrs – GMRI; Mike Pol – MA DMF; Chris Glass – UNH; Pingguo He – SMAST), fishermen (Jim Ford – F/V Lisa Ann III; Dan Murphy – F/V Bantry Bay, Tom Testaverde – F/V Midnight Sun) and a net maker (Jon Knight – Superior Trawl).