A Comparison of Fish and Invertebrate Catch from Two Small Demersal Beam Trawls in the Beaufort Sea

Both the US and Canada have conducted multi-year sampling of seafloor fauna in the Beaufort Sea using small demersal beam trawls. During the BOEM US-Canada Transboundary Fish and Lower Trophic Communities program 2012–2014, US researchers collected benthic fish and invertebrates from Pt. Barrow to the Mackenzie River mouth and Canadian scientists collected this information in the Beaufort Regional Environmental Assessment from the international border to Amundsen Gulf. Here, we compare the resulting benthic invertebrate and fish communities sampled in 2013 using the US 3-m plumb-staff beam trawl with those obtained from the Canadian beam trawl, which had larger mesh. Samples were collected at 42 locations along 6 shelf-to-slope transects (136.7 °W–146.1°W) at depths ranging from 20 to 1000 m near and west of the Mackenzie River outflow with both beam trawls. Differences in standardized catch per unit effort between gears were examined using nonparametric analyses. Based on our findings, catches between the two beam trawls can be considered indistinguishable in terms of the abundance, biomass, and overall community composition captured. Further analysis revealed that depth was a significant factor in catch composition of benthic fauna. There were no significant differences in fish sizes or taxa captured between the gears. Thus, direct comparisons of data collected from both programs can be made. This information improves our ability to examine fish and benthic invertebrate communities across the entire Beaufort Sea from Pt. Barrow in the west to Amundson Gulf in the east by allowing direct comparison between two distinct research programs.