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IS-BILAT-Mobilitet Norge-USA /Canada

Develop the capability for assessing sandeels in the North Pacific and North Sea acoustically

Tildelt: kr 0,18 mill.

I. The applicant, Espen Johnsen, will attend an experimental study in the Kodiak Island area, Alaska to measure the in situ target strength of Pacific sandeel. This will be an initial work in terms of developing an assessment program for the Pacific sande el. The field study will use the experience from the SMASSC NFR-project (project number 185065/S40) to carry out the measurements. Dr. Chris Wilson (Alaska Fisheries Science Centre), Dr. Robert Foy (Director AFSC Kodiak Laboratory) and Dr. Kate Wynne (Un iversity of Alaska) are very interested in carrying out such an experiment. The collected data from this study will be analysed in close collaboration with the scientists from Seattle and Kodiak, Alaska and a comparison study of target strength of Ammodyt es marinus and Ammodytes hexapterus will be done. II. The analyses of the survey data from the SMASSC project will be carried out throughout the stay in Seattle, where the main focus will be on the use of acoustic multi-frequency to identify sandeel sch ools and do further work on the size-dependent frequency response of sandeel schools. Another major task is to analyse the potential of using the data collected from the EK-60 SIMRAD echo-sounder (18, 38, 120 and 200 kHz) to map the seabed and identify th e areas containing high densities of sandeel. By using logistic regressions and classification tree models we will test the association between sandeel distribution and bottom types to optimize the survey effort. Dependent of available time in Seattle and the progress of the SMASSC project prior to the summer of 2009, Espen Johnsen will carry out analyses on the catch efficiency of the dredges versus grab, the day-night differences in the catch rates of the dredges and the stomach contents of the sandeel to explain the observed migration patterns in relation foraging and zoo-plankton availability. III. Espen Johnsen will attend relevant acoustic courses at University of Washington, School of Fisheries

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IS-BILAT-Mobilitet Norge-USA /Canada

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