Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July 2014 (NCEI Accession 0278728)
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.
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.
Dataset Citation
- Cite as: Steneck, Robert S.; Estes, James A.; Rasher, Douglas B. (2023). Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July 2014 (NCEI Accession 0278728). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0278728. Accessed [date].
Dataset Identifiers
ISO 19115-2 Metadata
gov.noaa.nodc:0278728
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Ordering Instructions | Contact NCEI for other distribution options and instructions. |
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NOAA National Centers for Environmental Information +1-301-713-3277 NCEI.Info@noaa.gov |
Dataset Point of Contact |
NOAA National Centers for Environmental Information ncei.info@noaa.gov |
Time Period | 2014-07-04 to 2014-07-17 |
Spatial Bounding Box Coordinates |
West: 173.249
East: 179.356
South: 51.403
North: 52.944
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Data Presentation Form | Digital table - digital representation of facts or figures systematically displayed, especially in columns |
Dataset Progress Status | Complete - production of the data has been completed Historical archive - data has been stored in an offline storage facility |
Data Update Frequency | As needed |
Purpose | This dataset is available to the public for a wide variety of uses including scientific research and analysis. |
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Data Center keywords | NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS Global Change Master Directory (GCMD) Data Center Keywords |
Platform keywords | NODC PLATFORM NAMES THESAURUS BCO-DMO Platform Names Global Change Master Directory (GCMD) Platform Keywords ICES/SeaDataNet Ship Codes |
Place keywords | NODC SEA AREA NAMES THESAURUS Global Change Master Directory (GCMD) Location Keywords Provider Place Names |
Project keywords | BCO-DMO Standard Programs BCO-DMO Standard Projects Provider Cruise IDs Provider Funding Award Information |
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Last Modified: 2024-05-31T18:50:46Z
For questions about the information on this page, please email: ncei.info@noaa.gov
For questions about the information on this page, please email: ncei.info@noaa.gov