by

• Main Authors: Dr. Richard, E. Crawford
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Barrow Canyon; Chukchi Sea; Arctic cod; Barrow; Beaufort Sea; Chukchi; Mackenzie Shelf; Phytoplankton; Zooplankton; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.369.5724; http://www.pws-osri.org/programs/projects/annual_reports/2009/09-10-03 final.pdf

This project identifies previously unknown demersal fish habitat along the continental slope along the eastern Chukchi Sea and Alaskan and Canadian Beaufort Sea waters. It is based on an analysis of several data sets obtained during JWACS 2002, a research expedition in the Beaufort and Chukchi seas in 2002. Data were collected by a variety of means: the ship‘s Acoustic Doppler Current Profiler (ADCP)—a 30-day record; a bongo net that collected plankton and larval fishes; a portable fish echo sounder operated prior to net sampling operations; the ship‘s hydrological profiling system (CTD/rosette); and a CTD-type data logger mounted on the bongo net. Data visualization techniques were used to explore and analyze data and to report results. Data synthesis consists of an evaluation of fish distribution in relation to the physico-chemical and bathymetric characteristics of their habitat. An extensive warm-water plume of Alaska Coastal Current water with phytoplankton, zooplankton and fish (presumably) was found reaching perhaps 300 km eastward from Barrow Canyon into western Beaufort Sea. ADCP backscatter from the plume was the highest of the study, indicating dense aggregations of biomass, perhaps mixed with marine snow. Only larval fish were found in the upper portion of the water column in the Chukchi Sea but Arctic cod of all age classes (i.e., larvae to adult) were in the upper 20 m at the northeastern Chukchi Sea shelf break and along the Alaskan and Mackenzie Shelf in the warm surface layer (2-5 o C). Shoals of fish were detected at the shelf break in eastern Chukchi Sea and along the Alaskan coast and the Mackenzie Shelf. Much larger shoals were detected in deeper waters along the continental slope (250-350 m) in the latter two areas, and at the bottom of Barrow and Mackenzie canyons. Fish were in Atlantic Water where temperatures were above 0 o C. Few fish were found in colder water between the surface layer and Atlantic Water. Results are discussed in the context of ecological considerations and impacts ...