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Title Sum-
Institution Dataset ID
   set  data   graph     files  public Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July
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The Dataset's Variables and Attributes

Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL access_formats String .htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson,.odvTxt
attribute NC_GLOBAL acquisition_description String 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)\u2014island
group\u2014as 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.
attribute NC_GLOBAL awards_0_award_nid String 526658
attribute NC_GLOBAL awards_0_award_number String PLR-1316141
attribute NC_GLOBAL awards_0_data_url String http://nsf.gov/awardsearch/showAward?AWD_ID=1316141 (external link)
attribute NC_GLOBAL awards_0_funder_name String NSF Arctic Sciences
attribute NC_GLOBAL awards_0_funding_acronym String NSF ARC
attribute NC_GLOBAL awards_0_funding_source_nid String 390
attribute NC_GLOBAL awards_0_program_manager String Henrietta N Edmonds
attribute NC_GLOBAL awards_0_program_manager_nid String 51517
attribute NC_GLOBAL cdm_data_type String Other
attribute NC_GLOBAL comment String island_benthic_survey_urchin_density_2014
Aleutian Islands, AK, July 2014
PI's: R. Steneck (UME), J. Estes (UCSCD)
version: 2019-01-30
attribute NC_GLOBAL Conventions String COARDS, CF-1.6, ACDD-1.3
attribute NC_GLOBAL creator_email String info at bco-dmo.org
attribute NC_GLOBAL creator_name String BCO-DMO
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.bco-dmo.org/ (external link)
attribute NC_GLOBAL data_source String extract_data_as_tsv version 2.3 19 Dec 2019
attribute NC_GLOBAL date_created String 2019-02-06T20:19:22Z
attribute NC_GLOBAL date_modified String 2019-02-25T18:46:13Z
attribute NC_GLOBAL defaultDataQuery String &time<now
attribute NC_GLOBAL doi String 10.1575/1912/bco-dmo.755115.1
attribute NC_GLOBAL Easternmost_Easting double 179.35628
attribute NC_GLOBAL geospatial_lat_max double 52.9441
attribute NC_GLOBAL geospatial_lat_min double 51.40283
attribute NC_GLOBAL geospatial_lat_units String degrees_north
attribute NC_GLOBAL geospatial_lon_max double 179.35628
attribute NC_GLOBAL geospatial_lon_min double 173.2486
attribute NC_GLOBAL geospatial_lon_units String degrees_east
attribute NC_GLOBAL infoUrl String https://www.bco-dmo.org/dataset/755115 (external link)
attribute NC_GLOBAL institution String BCO-DMO
attribute NC_GLOBAL keywords String bco, bco-dmo, biological, chemical, data, dataset, date, density, depth, depth_feet, dmo, erddap, island, latitude, longitude, management, name, observer, oceanography, office, preliminary, replicate, site, site_name, time, urchin, urchin_density
attribute NC_GLOBAL license String https://www.bco-dmo.org/dataset/755115/license (external link)
attribute NC_GLOBAL metadata_source String https://www.bco-dmo.org/api/dataset/755115 (external link)
attribute NC_GLOBAL Northernmost_Northing double 52.9441
attribute NC_GLOBAL param_mapping String {'755115': {'date': 'flag - time', 'latitude': 'flag - latitude', 'longitude': 'flag - longitude'}}
attribute NC_GLOBAL parameter_source String https://www.bco-dmo.org/mapserver/dataset/755115/parameters (external link)
attribute NC_GLOBAL people_0_affiliation String University of Maine
attribute NC_GLOBAL people_0_affiliation_acronym String U Maine DMC
attribute NC_GLOBAL people_0_person_name String Robert S. Steneck
attribute NC_GLOBAL people_0_person_nid String 526659
attribute NC_GLOBAL people_0_role String Principal Investigator
attribute NC_GLOBAL people_0_role_type String originator
attribute NC_GLOBAL people_1_affiliation String University of California-Santa Cruz
attribute NC_GLOBAL people_1_affiliation_acronym String UC Santa Cruz
attribute NC_GLOBAL people_1_person_name String James Estes
attribute NC_GLOBAL people_1_person_nid String 51389
attribute NC_GLOBAL people_1_role String Co-Principal Investigator
attribute NC_GLOBAL people_1_role_type String originator
attribute NC_GLOBAL people_2_affiliation String Bigelow Laboratory for Ocean Sciences
attribute NC_GLOBAL people_2_person_name String Douglas B. Rasher
attribute NC_GLOBAL people_2_person_nid String 480721
attribute NC_GLOBAL people_2_role String Co-Principal Investigator
attribute NC_GLOBAL people_2_role_type String originator
attribute NC_GLOBAL people_3_affiliation String Woods Hole Oceanographic Institution
attribute NC_GLOBAL people_3_affiliation_acronym String WHOI BCO-DMO
attribute NC_GLOBAL people_3_person_name String Nancy Copley
attribute NC_GLOBAL people_3_person_nid String 50396
attribute NC_GLOBAL people_3_role String BCO-DMO Data Manager
attribute NC_GLOBAL people_3_role_type String related
attribute NC_GLOBAL project String OA Kelp Forest Function
attribute NC_GLOBAL projects_0_acronym String OA Kelp Forest Function
attribute NC_GLOBAL projects_0_description String Extracted from the NSF award abstract:
Marine calcifying organisms are most at risk to rapid ocean acidification (OA) in cold-water ecosystems. The investigators propose to determine if a globally unique and widespread calcareous alga in Alaska's Aleutian archipelago, Clathromorphum nereostratum, is threatened with extinction due to the combined effects of OA and food web alterations. C. nereostratum is a slow growing coralline alga that can live to at least 2000 years. It accretes massive 'bioherms' that dominate the regions' rocky substrate both under kelp forests and deforested sea urchin barrens. It develops growth bands (similar to tree rings) in its calcareous skeleton, which effectively record its annual calcification rate over centuries. Pilot data suggest the skeletal density of C. nereostratum began to decline precipitously in the 1990's in some parts of the Aleutian archipelago. The investigators now propose to use high-resolution microscopy and microCT imaging to examine how the growth and skeletal density of C. nereostratum has changed in the past 300 years (i.e., since the industrial revolution) across the western Aleutians. They will compare their records of algal skeletal densities and their variation through time with reconstructions of past climate to infer causes of change. In addition, the investigators will examine whether the alga's defense against grazing by sea urchins is compromised by ongoing ocean acidification. The investigators will survey the extent of C. nereostratum bioerosion occurring at 10 sites spanning the western Aleutians, both inside and outside of kelp forests. At each site they will compare these patterns to observed and monitored ecosystem trophic structure and recent C. nereostratum calcification rates. Field observations will be combined with laboratory experiments to determine if it is a decline in the alga's skeletal density (due to recent OA and warming), an increase in grazing intensity (due to recent trophic-level dysfunction), or their interactive effects that are likely responsible for bioerosion patterns inside vs. outside of forests. By sampling C. nereostratum inside and outside of forests, they will determine if kelp forests locally increase pH via photosynthesis, and thus buffer the effects of OA on coralline calcification. The combination of field observations with laboratory controlled experiments, manipulating CO2 and temperature, will help elucidate drivers of calcification and project how these species interactions will likely change in the near future. The project will provide the first in situ example of how ongoing ocean acidification is affecting the physiology of long-lived, carbonate producing organisms in the subarctic North Pacific. It will also be one of the first studies to document whether OA, ocean warming, and food web changes to ecological processes are interacting in complex ways to reshape the outcome of species interactions in nature.
attribute NC_GLOBAL projects_0_end_date String 2016-08
attribute NC_GLOBAL projects_0_name String Ocean Acidification: Century Scale Impacts to Ecosystem Structure and Function of Aleutian Kelp Forests
attribute NC_GLOBAL projects_0_project_nid String 526660
attribute NC_GLOBAL projects_0_start_date String 2013-09
attribute NC_GLOBAL publisher_name String Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL Southernmost_Northing double 51.40283
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v55
attribute NC_GLOBAL subsetVariables String depth_feet,observer
attribute NC_GLOBAL summary String Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July 2014. Estimates were derived from visual surveys, performed via SCUBA.
attribute NC_GLOBAL time_coverage_end String 2014-07-17
attribute NC_GLOBAL time_coverage_start String 2014-07-04
attribute NC_GLOBAL title String Sea urchin density at central and western Aleutian Islands, Alaska from visual surveys, July 2014
attribute NC_GLOBAL version String 1
attribute NC_GLOBAL Westernmost_Easting double 173.2486
attribute NC_GLOBAL xml_source String osprey2erddap.update_xml() v1.3
variable island   String  
attribute island bcodmo_name String site
attribute island description String name of island
attribute island long_name String Island
attribute island units String unitless
variable site_name   byte  
attribute site_name _FillValue byte 127
attribute site_name actual_range byte 1, 46
attribute site_name bcodmo_name String site
attribute site_name description String identity of site
attribute site_name long_name String Site Name
attribute site_name units String unitless
variable latitude   double  
attribute latitude _CoordinateAxisType String Lat
attribute latitude _FillValue double NaN
attribute latitude actual_range double 51.40283, 52.9441
attribute latitude axis String Y
attribute latitude bcodmo_name String latitude
attribute latitude colorBarMaximum double 90.0
attribute latitude colorBarMinimum double -90.0
attribute latitude description String latitude of study site
attribute latitude ioos_category String Location
attribute latitude long_name String Latitude
attribute latitude nerc_identifier String https://vocab.nerc.ac.uk/collection/P09/current/LATX/ (external link)
attribute latitude standard_name String latitude
attribute latitude units String degrees_north
variable longitude   double  
attribute longitude _CoordinateAxisType String Lon
attribute longitude _FillValue double NaN
attribute longitude actual_range double 173.2486, 179.35628
attribute longitude axis String X
attribute longitude bcodmo_name String longitude
attribute longitude colorBarMaximum double 180.0
attribute longitude colorBarMinimum double -180.0
attribute longitude description String longitude of study site
attribute longitude ioos_category String Location
attribute longitude long_name String Longitude
attribute longitude nerc_identifier String https://vocab.nerc.ac.uk/collection/P09/current/LONX/ (external link)
attribute longitude standard_name String longitude
attribute longitude units String degrees_east
variable depth_feet   byte  
attribute depth_feet _FillValue byte 127
attribute depth_feet actual_range byte 20, 20
attribute depth_feet bcodmo_name String depth_w
attribute depth_feet colorBarMaximum double 8000.0
attribute depth_feet colorBarMinimum double -8000.0
attribute depth_feet colorBarPalette String TopographyDepth
attribute depth_feet description String depth of benthic survey
attribute depth_feet long_name String Depth
attribute depth_feet standard_name String depth
attribute depth_feet units String feet
variable time   double  
attribute time _CoordinateAxisType String Time
attribute time actual_range double 1.404432E9, 1.4055552E9
attribute time axis String T
attribute time bcodmo_name String date
attribute time description String calendar date of survey formatted as yyyy-mm-dd
attribute time ioos_category String Time
attribute time long_name String Date
attribute time nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/ (external link)
attribute time source_name String date
attribute time standard_name String time
attribute time time_origin String 01-JAN-1970 00:00:00
attribute time time_precision String 1970-01-01
attribute time units String seconds since 1970-01-01T00:00:00Z
variable observer   String  
attribute observer bcodmo_name String person
attribute observer description String last name of observer
attribute observer long_name String Observer
attribute observer units String unitless
variable replicate   byte  
attribute replicate _FillValue byte 127
attribute replicate actual_range byte 1, 20
attribute replicate bcodmo_name String replicate
attribute replicate description String replicate 0.25-m^2 quadrat
attribute replicate long_name String Replicate
attribute replicate units String unitless
variable urchin_density   short  
attribute urchin_density _FillValue short 32767
attribute urchin_density actual_range short 0, 201
attribute urchin_density bcodmo_name String abundance
attribute urchin_density description String density of sea urchins
attribute urchin_density long_name String Urchin Density
attribute urchin_density nerc_identifier String https://vocab.nerc.ac.uk/collection/P03/current/B070/ (external link)
attribute urchin_density units String count per 0.25 m^2

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.

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