TITLE: JOSS_SPRING_ISOTOPES_2004.xls JOSS_SUMMER_ISOTOPES_2004.xls AUTHOR: Ken Dunton, University of Texas at Austin Marine Science Institute 750 Channel View Drive, Port Aransas, TX 78373 dunton@utmsi.utexas.edu http://www.utmsi.utexas.edu/staff/dunton/ 361-749-6744 (phone) 361-749-6777 (FAX) DATA QUESTIONS: Susan Schonberg, University of Texas at Austin Marine Science Institute 750 Channel View Drive, Port Aransas, TX 78373 susans@utmsi.utexas.edu 361-749-6821 (phone) 361-749-6777 (FAX) FUNDING SOURCE AND GRANT NUMBER: National Science Foundation OPP-0125074 DATA SET OVERVIEW: Carbon and Nitrogen Isotope Dynamics Biological material from three levels in the ocean (POM, plankton, benthos) was collected to determine the natural abundance of 13C and 15N. Isotope data were used to trace the advection of northward flowing organic material through the Bering Strait into the Chukchi and Bering Seas. Isotope signatures also provided information about the trophic links between pelagic and benthic components of the shelf and slope within the study area. Collections were made from USCG R/V Healy during two expeditions through the Bering, Chukchi, and eastern Beaufort Seas. The first 6-week expedition occurred from 15 May to 23 June 2004 (Spring) and the second from 16 July to 26 August 2002 (Summer). SBI project web page: http://www.joss.ucar.edu/sbi/ INSTRUMENT DESCRIPTION: Water for filtration of POM was collected in CTD bottles from the photic zone (10-54 m). Zooplankton were collected with a plankton net by either PI Sherr's or PI Smith's groups. Benthic organisms were collected by van Veen grab by PI Grebmeier's group or by otter trawl or benthic dredge by Dunton's team. DATA COLLECTION & PROCESSING: The following types of samples were collected during each trip. 1. POM was sampled by filtering water onto a GFF and dried 2. Water column animals were caught by plankton net, identified, sorted and dried 3. Benthic invertebrates were collected using sediment cores, sieved, identified, sorted and dried Samples were acidified in 1 N HCL for several hours to remove carbonates, rinsed in distilled water, and dried at 60 °C. The dried samples were analyzed using a Finnegan MAT Delta Plus mass spectrometer at the University of Texas Marine Science Institute upon return from the expedition. DATA FORMAT: The data are in two separate Microsoft Excel files: Spring (HLY- 04-02) and Summer (HLY-04-03). Each file is divided into three electronic pages (POM, pelagic, and benthic). The column headings and units are: Station, Date, Latitude, Longitude, Depth, Name, Sample Number, d 15N and d 13C Isotopes Station: Ship-YY-Cruise no.-Station no. Date: YYYYMMDD Latitude and Longitude: decimal degrees Depth: total water and benthic collection depth in meters. Name: identification of the organism. Sample No.: unique identification number for sample. d 15N, d 13C Isotopes: results expressed in standard d notation relative to carbonate PeeDeeBelemnite and atmospheric nitrogen where: d 15N or d 13C (%) = [Rsample/Rstandard) -1] x 1000 and R=(15N/14N or 13C/12C), respectively.