AFSC/REFM: Stable Isotope collections from the North Pacific 2001-2008

d15N and d13C isotopic ratios from multiple groundfish and groundfish prey samples collected on groundfish surveys and by fishery observers onboard commercial fishing vessels in the eastern Bering Sea, and Gulf of Alaska from 2006 through 2008 via NPRB project, NPRB.2006.22.Isotopes, and continued by AFSC.

This research proposed to further define and understand the marine ecosystems that involve commercially important groundfish in the Bering Sea, Aleutian Islands and Gulf of Alaska.

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d15N and d13C isotopic ratios from multiple groundfish and groundfish prey samples collected on groundfish surveys and by fishery observers onboard commercial fishing vessels in the eastern Bering Sea, and Gulf of Alaska from 2006 through 2008. Measurements are species, individual length, and collection location; isotopic data is for dried samples and is percent Carbon, percent Nitrogen, C/N ratio by weight, and d15N and d13C isotopic ratios

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All data collected by observers are confidential under the Magnuson-Stevens Fishery Conservation and Management Act; as amended, Public Law 109-479; 16 U.S.C. 1853; implemented at 50 CFR 679.50. Therefore unprocessed (raw) observer data can be shared only with authorized persons; however aggregated forms of the data are generally available. In this data set vessel, cruise, lat, lon, gear depth, bottom depth, month, day fields within the table have been set to null for observer collected data to ensure anonymity of data collection source except Year, Region, and Hauljoin (which maintains relational integrity to the predprey and prey len tables)

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Excel spreadsheet.

Sample collection, freezing and drying protocols are described in manuals below. Dried sample mass was measured by trained laboratory personnel to a precision of 0.001mg 10.0015mg. Samples were analyzed for d15N, d13C, %C, %N, and C/N, in continuous-flow mode using a Thermo-Finnigan Deltaplus Advantage gas isotope-ratio mass spectrometer interfaced with a Costech Analytical ECS4010 elemental analyzer. Data are normalized using 4 internationally-accepted isotope reference standards (IAEA CH6, CH7, N1, and N2). The main working standard is peach leaves (NIST 1547). External precision on these standards is 1 0.10 or better for d13C and 1 0.20 or better for d15N

This data set was a combination of data collected by scientific personnel onboard Alaska Fisheries Science Center surveys and by fishery observers onboard commercial fishing vessels in the eastern Bering Sea and Gulf of Alaska as opportunity arose.

10% of tissue samples were sub-sampled and isotopic signatures measured twice to determine measurement variance. Peak amplitude and variance were recorded and sample results falling outside of the range of the machine were discarded.

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To be determined by NPRB.

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