Industry Report : Understanding Dredge Performance for a Lined versus Unlined NMFS Sea Scallop Dredge
Virginia Institute of Marine Science
Marine Advisory Program (MAP)
Marine Resource Report: 2020-6
The Virginia Institute of Marine Science (VIMS) tested a scale model of the sea scallop survey dredge in the flume tank at the Fisheries and Marine Institute of Memorial University over two days in March of 2019. This work was conducted to understand how the liner, survey protocols, and catch volume effect dredge performance. Tow speed, warp tension, maximum bag height, height at the twine top end, wire angle, wheel height of bottom, and dredge angle were measured for the trials. Tow speeds tested ranged from 3-4.5 kts. Video footage of trials was recorded and can be viewed at the VIMS Sea Scallop Program youtube channel: https://www.youtube.com/channel/UCUJpqwOCoiY89gd6Ok0rtxw.
Results indicated the liner did not negatively impact dredge performance compared to an unlined version of the survey dredge. The liner improved overall bag shape, dredge bag height, and twine top height, as well as hydrodynamic flow through the dredge. Other findings indicated catch volume increased dredge angle and the height of the wheel off bottom, especially as speed increased. Tow speeds should be kept under 4.3 kts to improve dredge performance and have the dredge fish more consistently.
Sea scallop fishery
Rudders, D., Roman, S., & Mohr, E. (2020) Industry Report : Understanding Dredge Performance for a Lined versus Unlined NMFS Sea Scallop Dredge. Marine Resource Report: 2020-6. Virginia Institute of Marine Science, William & Mary. doi: 10.25773/7qdx-b009