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OAS accession Detail for 0278728
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Title: Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July 2014 (NCEI Accession 0278728)
Abstract: This dataset contains biological and survey - biological data collected on R/V Point Sur during cruise PS1409 in the Bering Sea from 2014-07-04 to 2014-07-17. These data include abundance. These data were collected by Douglas B. Rasher of Bigelow Laboratory for Ocean Sciences, James Estes of University of California-Santa Cruz, and Robert S. Steneck of University of Maine as part of the "Ocean Acidification: Century Scale Impacts to Ecosystem Structure and Function of Aleutian Kelp Forests (OA Kelp Forest Function)" project and "Science, Engineering and Education for Sustainability NSF-Wide Investment (SEES): Ocean Acidification (formerly CRI-OA) (SEES-OA)" program. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2019-02-25.

The following is the text of the dataset description provided by BCO-DMO:

island benthic survey of urchin size and biomass-2014

Dataset Description:
Acquisition Description:
We characterized the ecological status of each island by quantifying the density, size frequency distribution, and biomass of the sea urchin community (primarily Strongylocentrotus polyacanthus ) at randomly selected sites, using the same methods that have been employed by us and others over the past 30 years (Estes et al. 2010). Originally, we identified potential study sites by laying a grid over a map of each island, marking every place a grid line intersected the coast; these marks were later assigned GPS waypoints. During the 2014 research cruise, we randomly selected and resampled six sites per island, or in the Semichi Islands (Alaid, Nizki, and Shemya)—island group—as this level of sampling is sufficient to determine the ecological status of an island (Estes et al. 2010). We performed identical community surveys at the sites we studied with respect to algal reef bioerosion (see associated metadata forms and datasets).

At each site, a diver placed a 0.25-m^2 quadrat at 20 feet depth and counted all urchins within the quadrat, then collected the urchins in a bag. The diver then took a random number of kicks along the same depth contour and repeated this process until 20 quadrats were sampled or 200 urchins were collected, whichever occurred first. If 200 urchins were collected quickly, additional density counts were made to yield a better density estimate (n = 4 minimum). Shipside, we measured the size (test diameter; mm) of each collected urchin with calipers. We then calculated its biomass using a known size-weight relationship (Estes et al. 2010). To estimate total urchin biomass for a site (grams per 0.25-m^2), we summed the biomass of all urchins collected at the site and divided that sum by the number of quadrats deployed.
Date received: 20190225
Start date: 20140704
End date: 20140717
Seanames: Bering Sea
West boundary: 173.249
East boundary: 179.356
North boundary: 52.944
South boundary: 51.403
Observation types: biological, survey - biological
Instrument types:
Datatypes: species abundance
Submitter:
Submitting institution: Biological and Chemical Oceanography Data Management Office
Collecting institutions: Bigelow Laboratory for Ocean Sciences, University of California - Santa Cruz, University of Maine
Contributing projects:
Platforms: POINT SUR (32P0)
Number of observations:
Supplementary information:
Availability date:
Metadata version: 1
Keydate: 2023-05-25 04:55:43+00
Editdate: 2023-05-25 04:56:17+00