The Assessment of Benthic Impacts of Raised Groundgear for the Eastern Bering Sea Pollock Fishery

Our collaborative group of scientists and industry professionals are addressing a critical issue the Alaska pollock fishing industry is facing – capturing pollock near the seafloor while minimizing crab, halibut, and salmon bycatch. Six groundgear configurations were designed to reduce seafloor contact and bycatch; they were tested at sea and are now being evaluated under the context of a fishery habitat impacts assessment that addresses concerns of the North Pacific Fishery Management Council. The pelagic trawl groundgear configurations incorporate various footrope materials, steel bobbins, and weight clusters, and differ based on component placement. We measured the performance, swept area and impact to biological features using DIDSON sonar and video footage, and then analyzed with nominal, contact-adjusted, and susceptibility-adjusted swept area calculations. From the quantitative impact comparisons we expect the raised groundgear to have a significant decrease in seabed contact and enough seafloor clearance between contact points to limit susceptibility of biological features. The raised groundgear would ultimately result in a smaller adverse impact on benthic habitats than the nominal swept area might otherwise indicate. This presentation focuses on the gear design and direct observations of performance and impact, or lack thereof.