Beaufort Regional Environmental Assessment (BREA) Marine Fishes Project - Isotope data; Foodweb study on the Canadian Beaufort Sea 2013
Ship: CCGS Amundsen CA
Principal Investigator: Reist, Jim
Start Date: 01-08-2013
End Date: 12-09-2013
Citation: Unpublished data
Abstract: Fish, benthic invertebrates (infauna and epifauna), plankton, and sediment were collected from each trawling station with box cores and a range of nets. The 2013 cruise was split into two legs. Leg 1 samples were collected from six transects: Cape Parry (cpy), Bennett Point (bpt), Darnley Bay (dar), Ulukhaktok (ulu), Cape Bathurst, and the esc transect running from Nearshore from Cape Bathurst to offshore of Tuktoyaktuk. A total of 35 stations ranging from from 20-750m were sampled. Leg two consisted of four transects: Garry (gry), Transboundary (tbs), A1 (a transect in U.S. waters), and a deepwater transect (dwt). A total of 23 stations were sampled ranging from 40m to 1500m depth. Representative, abundant (i.e., not rare) taxonomic groups and feeding guilds were collected as representatives of the benthic and pelagic food webs at each station. Invertebrates were either removed from nets or sieved from box cores, and taxa were collected in replicates of three. Fish were removed from nets, and approximately 8-10 fish/taxa were selected for isotope analysis. Dominant plankton taxa that represented a range of feeding guilds within the pelagic food web (including copepods, chaetognaths, & amphipods) were also collected from each station. Small portions of muscle tissue, body wall, viscera or whole animals (if too small for dissection) were taken and stored frozen at -20 °C until further processing. From box cores, two small subsamples (about 10 g wet weight each) of surface sediment (upper 1 cm) were also collected and for stable isotope and chlorophyll (chl) a analysis. Once initial processing has occurred, samples will be dried, homogenized, and weighed for analysis of stable carbon and nitrogen isotope ratios. This project is designed to study the benthic and pelagic food web based on stable carbon and nitrogen isotopic ratios as part of the Beaufort Regional Environmental Assessment (BREA) marine fishes program. Changes in food web positions and relationships between key fish and invertebrate species will also be investigated across depth gradients and across distinct oceanographic habitats (influence of water originating from the Pacific Ocean, Atlantic Ocean, and Mackenzie River).