Forage Fish habitat distribution in Arctic Waters
Forage Fish habitat distribution in Arctic WatersRichard Crawford, Prince William Sound Science Center
Scope of Work:
This project will identify pelagic fish habitat near the shelf break in Alaska’s offshore Arctic waters. It will consist of an evaluation of fish distribution in relation to ocean currents and the physico-chemical characteristics of their pelagic habitat. This information will be transferred by overlays to bathymetric maps of the region to identify areas where pelagic fish occur. The maps will greatly expand our knowledge of fish habitat in this poorly understood area. The synthesis is based on analysis of several data sets obtained during a research expedition in the Beaufort and Chukchi seas in 2002. The data were collected with 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 during net sampling operations; the ship’s water profiling system (CTD) that was operated at the net sampling stations and at numerous other sites along the cruise track; and a CTD-type data logger mounted on the bongo net. Data visualization techniques will be used to explore and analyze data and to report results. I will apply novel visualization techniques to examine the ADCP record for locations along the cruise track where the ship passed over concentrations of fish. The fish echo analysis will be enhanced by incorporating the results of the bongo net sampling project and the analysis of the echo sounder records. Fish distribution will be plotted on digitized electronic bathymetric maps to relate fish habitat to the physical environment. I will augment the maps’ content by overlaying relevant physico-chemical habitat characteristics derived from data collected with the ship’s CTD and the data logger on the bongo net. Emphasis will be placed on comparing the distribution of fish habitat across and along the shelf (i. e. , by depth zone and by latitudinal gradient). Results will be discussed in the context of ecological considerations and the location of existing and planned human activity (e. g. , hydrocarbon extraction and shipping).