1b:I[42426,["/_next/static/immutable/chunks/1xctgzqre-wsy.js","/_next/static/immutable/chunks/06_-wz6pdtp2b.js","/_next/static/immutable/chunks/30e52g49hg40p.js","/_next/static/immutable/chunks/02yq6tul2z-oh.js","/_next/static/immutable/chunks/10bx_ec2vj7n_.js","/_next/static/immutable/chunks/33bfn03fo8xnt.js","/_next/static/immutable/chunks/0tfjf78scu61b.js","/_next/static/immutable/chunks/31xnvej4n1bi9.js"],"default"] 1c:T82f,

Sampling locations were from the Aleutian Archipelago offshore between longitude 173.9 and -167.6 in June 2016 and July 2017.

Trawls were conducted with a 3.05 m plumb-staff beam trawl with a 7-mm mesh and a 4-mm codend liner (Gunderson & Ellis, 1986). For each trawl, the trawl net was towed for approximately 3 minutes on the seafloor with the vessel traveling at 1.5 knots. A temperature-depth recorder was attached to the trawl net to determine effective trawling distances. The start of each trawl was determined by the time at which the trawl net stopped descending in the depth profile, and the end of each trawl was determined by the time the trawl net began ascending. Trawl distances were determined by referencing the GPS coordinates of the research vessel for the start and end times of each trawl event. Occasionally, the trawl net became damaged by rocks during a trawl event, preventing effective sampling after the collision. For these trawls, the collision point was detectable by a sudden decrease in depth of the trawl net, and the effective trawling swath was assumed to be from the beginning of the trawl up to the collision point.

Organisms were sorted and identified to the lowest taxonomic level feasible. Members of each taxonomic group were counted and their damp-biomass (including shells for mollusks and crabs) was determined. Voucher specimens were prepared in 10% buffered formalin for those taxa that could not be identified in the field.

Some large samples were split in half. This is Indicated as the subsample_factor. A value of 2 (trawl 24) indicates that half of the trawl contents were taken for biomass and count measurements. The biomass and count values in the area-standardized data sheets are estimated by doubling the values recorded for the subsampled portion.

For sample #30, the biomass of Echinarachnius parma was not recorded. The biomass listed is an estimate based on the average biomass per individual from each other sample containing E. parma, multiplied by the number of E. parma found in the sample.

1d:T57d,A beam trawl consists of a cone-shaped body ending in a bag or codend, which retains the catch. In these trawls the horizontal opening of the net is provided by a beam, made of wood or metal, which is up to 12 m long. The vertical opening is provided by two hoop-like trawl shoes mostly made from steel. No hydrodynamic forces are needed to keep a beam trawl open. The beam trawl is normally towed on outriggers, one trawl on each side. While fishing for flatfish the beam trawl is often equipped with tickler chains to disturb the fish from the seabed. For operations on very rough fishing grounds they can be equipped with chain matrices. Chain matrices are rigged between the beam and the groundrope and prevent boulders/stones from being caught by the trawl. Shrimp beam trawls are not so heavy and have smaller mesh sizes. A bobbin of groundrope with rubber bobbins keeps the shrimp beam trawl in contact with the bottom and gives flatfish the opportunity to escape. Close bottom contact is necessary for successful operation. To avoid bycatch of most juvenile fishes selectivity devices are assembled (sieve nets, sorting grids, escape holes). While targeting flatfish the beam trawls are towed up to seven knots, therefore the gear is very heavy; the largest gears weighs up to 10 ton. The towing speed for shrimp is between 2.5 and 3 knots. (from: http://www.fao.org/fishery/geartype/305/en)1e:Tcd2,NSF abstract: In many ecosystems the presence of a single dominant species can modify the physical conditions of the environment and alter patterns of biodiversity, nutrient cycling, and primary production. Losses of these "ecosystem engineers" can have profound impacts to how ecosystems function. Coastal kelps provide excellent examples of organisms whose structure modifies the physical characteristics of their habitats (light, nutrients, water motion) and supports enhanced biodiversity. The kelp forests in the coastal waters of the Aleutian Archipelago have suffered large-scale declines over the past several decades. This project will examine how these losses impact patterns of ecosystem production and biodiversity using a combination of techniques ranging from in situ benthic chambers and shipboard incubations to remote sensing using satellite imagery. The results will provide an understanding of how such events may impact this and other ecosystems. This project will support graduate students and will introduce the public to the Aleutian ecosystems in a series of videos. The investigators will also work with a San Diego high school teacher to integrate project findings into classroom activities, and they expect to involve a teacher in their field program. The investigators will ask two highly integrated questions: 1) How do the widespread losses of kelp forests impact benthic productivity across the Aleutian Archipelago? 2) How do the widespread losses of kelp forests impact benthic biodiversity and community structure across the archipelago? To address these, the investigators will estimate changes to productivity at ten islands where they have historic data on seaweed community composition and estimates of kelp canopy cover. They will use in situ benthic chambers placed in both kelp forests and urchin barrens to measure plot-scale patterns of net ecosystem productivity (NEP), and shipboard incubations to examine net primary productivity (NPP) for the dominant macroalgae. Data for individual species rates of NPP will be scaled by their biomass and combined with in situ plot-scale benthic chamber experiments of whole communities to estimate NEP at the islands visited. These estimates will be scaled up to calculate NEP across the entire archipelago by first extrapolating results from the study sites to entire islands, and then across the archipelago. They will also estimate broad-scale patterns in production by characterizing water column irradiances across the archipelago and modeling NPP using species-level relationships between irradiance and photosynthesis. Coupling these with estimates of water column irradiance and community respiration will allow modeling of NEP across this region. Benthic biodiversity will be assessed using diver surveys and shipboard benthic trawls. Following these activities, satellite remote sensing of the kelp canopies dating back to the 1980s and the investigators' own historical data on benthic macroalgal abundances at these and other islands will be used to estimate the temporal and spatial patterns of change across the archipelago. For more information see: Project blog: http://sdsukelp.weebly.com/blog Project website: http://www.uaf.edu/cfos/research/projects/collaborative-research--/6:["$","$L1b",null,{"dataset":{"_id":"729873","description":"

This dataset includes epibenthic community biomass collected offshore by trawls and reported as kilograms per 100 square meters.

\n","problem":"","acquisition":"$1c","processing":"

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- corrected spelling of 5 taxa to agree with World Register of Marine Species names. See Parameter list below for submitted names, in parentheses.

\n","bcodmoProcessing":"","title":"Biomass data from Aleutians offshore epibenthic trawls from R/V Oceanus OC1606A, OC1707A, 2016-2017 (Kelp Forest Ecosystem Engineer Loss project)","nickname":"Trawl biomass","dataUrl":"","currentState":"Final no updates expected","currentStateId":"7","validated":true,"restricted":false,"version":"2","version_date":"2019-01-09T05:00:00.000Z","abstract":"This dataset includes epibenthic community biomass collected offshore by trawls and reported as kilograms per 100 square meters.","citation":"Edwards, M., Konar, B. (2019) Biomass data from Aleutians offshore epibenthic trawls from R/V Oceanus OC1606A, OC1707A, 2016-2017 (Kelp Forest Ecosystem Engineer Loss project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 2) Version Date 2019-01-09 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/729873 [access date]","citationParts":{"identifier":"http://lod.bco-dmo.org/id/dataset/729873","versionDate":"2019-01-09","versionId":"2","year":"2019","title":"Biomass data from Aleutians offshore epibenthic trawls from R/V Oceanus OC1606A, OC1707A, 2016-2017 (Kelp Forest Ecosystem Engineer Loss project)","authors":"Edwards, M., Konar, B.","publisher":"Biological and Chemical Oceanography Data Management Office (BCO-DMO)."},"doi":"","release_date":"2019-03-25T04:00:00.000Z","field_dataset_location":"","temporal_extent":{"start":"2016-06-19T04:00:00.000Z","end":"2017-07-23T04:00:00.000Z"},"temporal":{"resolution":"time:unitDay","type":"time:Interval","start":{"value":"1466308800","label":"2016-06-19"},"end":{"value":"1500782400","label":"2017-07-23"}},"spatial_extent":{"shape":"polygon","center":{"latitude":52.41885,"longitude":-173},"wkt":"POLYGON ((-179 51.4269, -167 51.4269, -167 53.4108, -179 53.4108, -179 51.4269))","north":53.4108,"east":-167,"south":51.4269,"west":-179},"dataset_type":["Cruise Results"],"keywords":["biota","oceans"],"data_files":[{"id":"902047","title":"biomass_trawl.csv","url":"https://datadocs.bco-dmo.org/dataset/729873/file/1VVMO6mTARzOL/biomass_trawl.csv","showTableUrl":"https://www.bco-dmo.org/dataset/729873/data/view/902047","description":"Primary data file for dataset ID 729873","filename":"biomass_trawl.csv","bytesize":37786,"checksum":{"value":"7811c233ec4f8004723ca802eeac18d6","Algorithm":{"_id":"190","name":"MD5"}},"mimetype":"text/csv","fileType":{"_id":"192","name":"Comma Separated Values (.csv)"},"isErddap":"","date":"","isPublicDuringEmbargo":false,"primaryDataFile":true,"showTable":true,"restricted":false}],"supplemental_files":[],"roles":[{"role":{"_id":"138","name":"Principal Investigator"},"performedBy":{"_id":"51390","name":"Matthew Edwards"},"performedAtOrganization":{"_id":"73","name":"San Diego State University"}},{"role":{"_id":"140","name":"Co-Principal Investigator"},"performedBy":{"_id":"51388","name":"Brenda Konar"},"performedAtOrganization":{"_id":"13","name":"University of Alaska Fairbanks"}},{"role":{"_id":"133","name":"Contact"},"performedBy":{"_id":"727069","name":"Aaron S. Bland"},"performedAtOrganization":{"_id":"13","name":"University of Alaska Fairbanks"}},{"role":{"_id":"145","name":"BCO-DMO Data Manager"},"performedBy":{"_id":"50396","name":"Nancy Copley"},"performedAtOrganization":{"_id":"191","name":"Woods Hole Oceanographic Institution"}}],"deployments":[{"_id":"727190","name":"OC1606A","synonyms":[],"dates":{"start":"2016-06-17T00:00:00.000Z","end":"2016-07-02T00:00:00.000Z"},"platform":{"_id":"53997","name":"R/V Oceanus"},"chiefScientists":[{"id":"727191","name":"Genoa Sullaway","role":"Chief Scientist"}]},{"_id":"729428","name":"OC1707A","synonyms":[],"dates":{"start":"2017-07-18T00:00:00.000Z","end":"2017-07-25T00:00:00.000Z"},"platform":{"_id":"53997","name":"R/V Oceanus"},"chiefScientists":[{"id":"51390","name":"Matthew Edwards","role":"Chief Scientist"}]}],"funding":[{"_id":"709510","name":"OCE-1435205","fundingSource":{"_id":"355","name":"NSF Division of Ocean Sciences"},"url":"https://www.nsf.gov/awardsearch/show-award?AWD_ID=1435205"},{"_id":"709515","name":"OCE-1435194","fundingSource":{"_id":"355","name":"NSF Division of Ocean Sciences"},"url":"https://www.nsf.gov/awardsearch/show-award?AWD_ID=1435194"}],"instruments":[{"_id":"729883","name":"","description":"A 3.05 m plumb-staff beam trawl with a 7-mm mesh and a 4-mm codend liner","type_id":"521","type_name":"Beam Trawl","type_desc":"$1d","type_acronym":"Beam trawl"}],"parameters":[{"_id":"763186","name":"Island","format":"","frictionlessType":"","description":"

sampled Island location

","units":{"_id":"","name":"unitless"},"type":{"_id":"1124","name":"site","description":"

Sampling site identification.

"}},{"_id":"763187","name":"Region","format":"","frictionlessType":"","description":"

A priori region designation: central; east; west; far-west

","units":{"_id":"","name":"unitless"},"type":{"_id":"952","name":"region","description":"

geographical area of sampling

"}},{"_id":"763188","name":"Trawl_Distance_m","format":"","frictionlessType":"","description":"

Effective trawling distance based on estimates of trawling start/end locations

","units":{"_id":"","name":"meters"},"type":{"_id":"1073","name":"no_bcodmo_term","description":"

An association with a community-wide standard parameter has not yet been made.

"}},{"_id":"763189","name":"Trawl_Area","format":"","frictionlessType":"","description":"

Effective trawling area; trawl distance multiplied by the trawling width of the net (2.26 m)

","units":{"_id":"","name":"meters^2"},"type":{"_id":"662800","name":"surface_area","description":"

The total area of the surface of a three-dimensional object or organism. For example, a coral colony.

"}},{"_id":"763190","name":"Subsample_Factor","format":"","frictionlessType":"","description":"

Subsample indicator. Value of 2 indicates that half of the trawl contents were taken for biomass and count measurements.

","units":{"_id":"","name":"unitless"},"type":{"_id":"1087","name":"samp_fraction_denom","description":"

denominator of split fraction. e.g. for 1/2 split, samp_fraction_denom is 2; but for 3/4, it is 1.333 (4/3). Units are specific to the data set in which it appears.

"}},{"_id":"763191","name":"Start_Latitude","format":"","frictionlessType":"","description":"

Estimated location of the research vessel when the trawl net reached the bottom

","units":{"_id":"","name":"decimal degrees"},"type":{"_id":"730","name":"latitude","description":"

latitude, in decimal degrees, North is positive, negative denotes South; Reported in some datasets as degrees, minutes

"}},{"_id":"763192","name":"Start_Longitude","format":"","frictionlessType":"","description":"

Estimated location of the research vessel when the trawl net reached the bottom

","units":{"_id":"","name":"decimal degrees"},"type":{"_id":"731","name":"longitude","description":"

longitude, in decimal degrees, East is positive, negative denotes West; Reported in some datsets as degrees, minutes

"}},{"_id":"763193","name":"End_Latitude","format":"","frictionlessType":"","description":"

Estimated location of the research vessel when the trawl net reached the bottom OR the net collided with a rock (ending effective trawling)

","units":{"_id":"","name":"decimal degrees"},"type":{"_id":"730","name":"latitude","description":"

latitude, in decimal degrees, North is positive, negative denotes South; Reported in some datasets as degrees, minutes

"}},{"_id":"763194","name":"End_Longitude","format":"","frictionlessType":"","description":"

Estimated location of the research vessel when the trawl net reached the bottom OR the net collided with a rock (ending effective trawling)

","units":{"_id":"","name":"decimal degrees"},"type":{"_id":"731","name":"longitude","description":"

longitude, in decimal degrees, East is positive, negative denotes West; Reported in some datsets as degrees, minutes

"}},{"_id":"763195","name":"Start_Date_UTM","format":"","frictionlessType":"","description":"

Starting time for each trawl event; UTC

","units":{"_id":"","name":"unitless"},"type":{"_id":"1070","name":"date","description":"

date; generally reported in GMT as YYYYMMDD (year; month; day); also as MMDD (month; day); EqPac dates are local Hawaii time. ISO_Date format is YYYY-MM-DD (http://www.iso.org/iso/home/standards/iso8601.htm)

"}},{"_id":"763196","name":"Sample","format":"","frictionlessType":"","description":"

sample identifier

","units":{"_id":"","name":"unitless"},"type":{"_id":"960","name":"sample","description":"

unique sample identification or number; any combination of alpha numeric characters; precise definition is file dependent

"}},{"_id":"763197","name":"Acarnus_spp","format":"","frictionlessType":"","description":"

biomass of Acarnus spp.