Sampling locations were from the Aleutian Archipelago nearshore between longitude 173.9 and -167.6 in June 2016 and July 2017. The average depth 17.5 ft.
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To assess community structure at each site, two methods were used. First, to quantify the remainder of the epibenthic community, ten 0.25 m2 quadrats were haphazardly placed within each site. Within these quadrats, the percent bottom cover was visually estimated for bare substrate, kelp holdfasts, suspension feeders, pulvinate green algae (Codium spp.), and non-geniculate coralline algae - with differentiation made between Clathromorphum spp. and other encrusting coralline species.
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Following visual estimation, all epibenthic organisms\u2014excepting those strongly adhered to the substrate (e.g., barnacles, non-geniculate coralline algae, etc.)\u2014 were scraped from the substrate and placed in fine mesh collection bags for shipboard identification, and abundance and biomass determination. Second, three 10 m x 2 m swaths were placed haphazardly within each site. Within each swath, E. fistulosa stipes were counted, midwater and demersal fishes visually quantified by trained divers, and Also, all conspicuous, sparsely distributed large mobile invertebrates (i.e., sea stars, crab, and large gastropods with distributions assumed to be less than 1 per 2.5 m2, the total area covered by the above quadrats) were collected in fine mesh bags for shipboard abundance and biomass determination. Once onboard, organisms were identified to the lowest possible taxa, counted (if the species occur as discrete individuals) and weighed using hanging spring scales to determine biomass to the nearest .005 kg. Ambiguous or difficult to identify individuals were preserved in 10% formalin (for invertebrates) or pressed (for algae) for later identification.
All statistical analyses were done using PRIMER-E v. 7.0.13 (Clarke and Gorley 2015). Prior to multivariate analyses, abundance and biomass data were standardized to m2 to allow for pooling across sampling methods using Microsoft Excel for Mac v.16.9.
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BCO-DMO Processing Notes:
\n- added conventional header with dataset name, PI name, version date
\n- modified parameter names to conform with BCO-DMO naming conventions
\n- added Lat and Long columns from sampling site dataset
\n- reduced decimal precision of depth and depth_stdev from 13 decimal places to 1; reduced abundance columns from 16 decimal places to 2 or none for 0.
\n- corrected spelling of 6 taxa to agree with World Register of Marine Species names