Shelf-Basin Interactions (SBI) 2002 Zooplankton biomass (dry weight) data from cruise HLY0203, 16 July - 24 August 2002 Sharon Smith (PI), Peter Lane (Res. Assoc), and Leopoldo Llinçs (PhD student) Rosenstiel School of Marine and Atmospheric Science University of Miami 4600 Rickenbacker Causeway Miami, FL 33149 E-mail and telephone contacts: sharon.smith@rsmas.miami.edu telephone: 305-421-4819 plane@rsmas.miami.edu telephone: 305-421-4818 lllinas@rsmas.miami.edu telephone: 305-421-4817 Funding source and grant number: National Science Foundation, OPP-0125004 Data set overview: Zooplankton samples were collected from the USCGC Healy between 17 July and 24 August 2002. Sampling focused on several sections over the shelf and slope regions in the northern and eastern Chukchi Sea and western Beaufort Sea and occasionally extended northward into the Canada Basin. These sections, in chronological order of sampling, were denoted as Alaskan Coastal Water (ACW), Barrow Canyon (BC); East Barrow (EB); East Hanna Shoal (EHS); West Hanna Shoal (WHS); Hanna Canyon (HC); and Herald Valley (HV). Zooplankton samples were collected early in the cruise with a 1-meter MOCNESS (Wiebe et al., 1976), fitted with 153 ´m mesh nets, at two stations in the northeastern Chukchi Sea. Samples were collected at ca. 20 m depth intervals from near-bottom to the surface. Unfortunately, the MOCNESS was damaged by collisions with ice-floes during the third deployment. Heavy ice-cover and the inability to repair the MOCNESS necessitated using Bongo nets for the remainder of the cruise. Samples were collected at 31 stations by vertically hauled Bongo nets with a 60 cm diameter net-mouth and 153 ´m and 335 ´m mesh nets (Sea-Gear Corporation). Sample depths were from near-bottom to the surface over the shelf where bottom depth was less than 100 m. When bottom depth was greater than 100 m, Bongo nets were deployed to either 100 m and near-bottom; or 100 m, 600 m and 1000m at process study stations; or to ca. 400-600 m at intermediate CTD stations. Nets were generally lowered at 20 m/min and retrieved at 30 m/min. Maximum depths sampled were determined with a Wildlife Computers Mk9 depth recorder that was attached to the top of the Bongo frame. The volume filtered was calculated following the method described by Weikert and John (1981). Each sample was split on board the ship in a modified Folsom splitter that delivered four subsamples of 50%, 20%, 20% and 10%. For biomass measurements, a 20% fraction was poured through nested sieves of 1050 ´m, 560´m and 202 ´m mesh, and each size-fraction was then collected on pre-weighed 9 cm Whatman number 1 filter papers and placed in a drying oven at ca. 55 deg C for at least 48 hours. Phytoplankton clogged the 202 ´m mesh sieve at many coastal and shelf locations rendering that size-fraction useless for zooplankton biomass determination. At the end of the cruise all dry weight samples were packed in air-tight containers with desiccant for transport to the laboratory. Laboratory analyses were performed at the University of Miami's Rosenstiel School of Marine and Atmospheric Science. All dry weight samples returned to the lab were placed in drying oven at ca. 55 deg C. The dried biomass samples for the present report were weighed on a Mettler B5 analytical balance. The biomass data submitted with this file to the Joint Office for Science Support (JOSS)/UCAR are organized in three files: 1) "hly0203_zoobiomass_bongo153.txt" refers to biomass measurements from cruise hly0203 Bongo net collections with 153 micrometer mesh nets; 2) "hly0203_zoobiomass_bongo335.txt" refers to biomass measurements from cruise hly0203 Bongo net collections with 335 micrometer mesh nets; 3) "hly0203_zoobiomass_moc153.txt" refers to biomass measurements from cruise hly0203 MOCNESS net collections with 153 micrometer mesh nets. References Weikert, H., John, H.-Ch., 1981. Experiences with a modified BÄ multiple opening-closing plankton net. Journal of Plankton Research, 3, 167-176. Wiebe, P.H., Burt, K.H., Boyd, S.H., Morton, A.W., 1976. A multiple opening/closing net and environmental sensing system for sampling zooplankton. J. Mar. Res., 34, 313-326.