Benthic data from the environment and marine resources assessment of Imperial Oil/BP Exploration License Areas 446, 449, 451 and 453 (Beaufort Sea), in the summers of 2009, 2010 and 2011

A first survey was conducted in and around EL446 onboard the CCGS Amundsen from 16 July to 30 July, 2009. A total of 21 biophysical stations were sampled, involving 25 box core deployments and 18 Agassiz trawl tows. In addition, the Remotely Operated Vehicle (ROV) was deployed once (station 10) for epibenthos observation. A second survey was conducted in EL449 and EL451 onboard the CCGS Amundsen from 12 August to 26 August, 2010. A total of 18 biophysical stations were sampled, comprising 25 box core deployments and 18 Agassiz trawl tows. A third survey was conducted in EL451 and EL453 onboard the CCGS Amundsen from 7 September to 22 September 2011. A total of 13 biophysical stations were sampled, comprising 18 box core deployments and 13 Agassiz trawl tows.

The box core was deployed to quantitatively sample diversity and abundance of endobenthic organisms. After retrieval of the box core, a subsample of about 0.125 m2 area and 12-15 cm depth was collected and passed through a 0.5 mm mesh sieve to separate sediment from endofauna. Organisms were immediately preserved in a 4% buffered formaldehyde solution for further taxonomical identification in the laboratory. The volume of sediments sieved from each box core was measured (depth × width × length) to the nearest 1 cm to estimate endobenthic fauna density in each sample.

An Agassiz trawl (1.5 m width × 0.7 m height, cod end of 0.5 cm mesh size) was towed on the seabed at a speed of 1.5 - 2 knots for about 3 to 5 minutes to survey epibenthic species diversity and abundance. Retrieved samples were washed with seawater in a sieve (0.5 mm mesh), and organisms were counted and identified to the lowest taxonomical level possible.