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Resource Assessment & Conservation Engineering (RACE) Division

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Research Reports
Jan-Feb-Mar 2007
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Groundfish Assessment Program

Groundfish Research and Analysis

Dr. James (Jay) Orr accepted an invitation to serve as Visiting Professor and Research Scholar of Kyoto University in Japan for the January to March quarter. He has been working with Japanese ichthyologists and examining fish specimens for several projects on the systematic taxonomy of North Pacific fishes. His research has included work on the rougheye and blackspotted rockfishes (with Sharon Hawkins, ABL), the description of a new species of skate from the Aleutian Islands related to the Alaska skate (with Duane Stevenson, Gerald Hoff, and John McEachran of Texas A&M), and the taxonomy of North Pacific sand lance (with Y. Kai of Kyoto University). Because important specimens are archived in several collections around Japan, he has spent several weeks traveling to facilities in other parts of the country, including Kyoto University’s Fisheries Research Station in Maizuru, Hokkaido University’s Faculty of Fisheries Museum of Zoology in Hakodate, and the National Science Museum in Tokyo.

Dr. Duane Stevenson is assisting Alaska Sea Grant in the final preparation of a “Field Guide to the Cartilaginous Fishes of Alaska” to be published this summer. He is also continuing preparation of a manuscript describing patterns of distribution and abundance in the skates of Alaska and another revising the zoarcid genus Bothrocara (with E. Anderson of the South African Institute for Aquatic Biology).

By Jay Orr


Bottom Trawl Survey Staff Meets with NWFSC and Canadian Colleagues

For the past 4 years, AFSC bottom trawl survey staff has met annually with colleagues from the Northwest Fisheries Science Center (NWFSC) and the Canadian Department of Fish and Oceans (Pacific Biological Station, Nanaimo, B.C.) who do comparable groundfish research operations at their respective agencies. The working group was instigated under the auspices of the Technical Subcommittee of the Canada-U.S. Groundfish Committee and affords survey scientists from these agencies the opportunity to regularly compare methods, survey designs, and recent developments in the science behind fishery-independent trawl surveys of groundfish and invertebrate resources in the North Pacific and eastern Bering Sea.

AFSC scientists hosted the 2007 meeting on 20 February. AFSC scientists presented a summary of work done to improve measurement of survey trawl effort (distance fished and net width) and summarized progress on a project to investigate how inclusion of rocky or otherwise severe bathymetric portions of the survey area inaccessible to standard bottom trawls may bias stock assessments. NWFSC scientists reported on their current West Coast survey sampling scheme, described updates to the equipment and software used to record and analyze data, and summarized research on the impact of sea state on trawl survey catches. Canadian scientists reviewed their overall strategy of the suite of surveys they conduct off British Columbia, presented a recent business review of their Queen Charlotte Sound bottom trawl survey, and discussed implications of a decision regarding selling fish caught during research charters to help defray the cost of the research programs.

By Mark Wilkins


Ergonomics of At-Sea Sampling Assessed

The Groundfish Program’s Safety Committee, which has expanded to include seagoing staff from the Resource Ecology and Fisheries Management (REFM) and Fisheries Monitoring and Analysis (FMA) Divisions, organized an ergonomic assessment of the typical work conditions for sampling catches aboard charter vessels used to conduct bottom trawl surveys.

On 15 March, a mock deck set up–complete with tables used for sorting, weighing, and collecting specimens and data from fish and invertebrates and all of the sampling equipment routinely used during operations at sea–was used for the ergonomic assessment. Ergonomics specialist Joe Duran (NOAA Regional Safety Manager) was shown the typical workflow of sampling trawl catches during the surveys, including all the tools and tasks that field scientists are required to perform. The demonstration was informative and at the next meeting, Joe will provide the Safety Committee his assessment of improvements that should be considered to the workflow, equipment, and task assignment protocols that could improve the safety and well-being of our field staff aboard the vessels.

By Mark Wilkins


Presentations (2007 Alaska Marine Science Symposium)

Brian Knoth and Chris Rooper of the Groundfish Program each presented a poster (in absentia) at the Alaska Marine Science Symposium held in Anchorage from 21 to 24 January. (See the AFSC Poster database at http://access.afsc.noaa.gov/pubs/posters/poster_search.php.)

Brian’s poster was entitled “Arrowtooth flounder (Atheresthes stomias) diet and prey consumption near Kodiak Island, AK” (.pdf, 526KB). The research examined temporal (interannual and within-year), spatial, and ontogenetic differences in the diet and prey consumption of the nearshore arrowtooth flounder (ATF) population. The study highlighted the adaptable feeding behavior of ATF and provided baseline data concerning the magnitude of ATF prey consumption near Kodiak. This work was conducted in collaboration with Dr. Robert Foy of the University of Alaska Fairbanks.

Chris’s poster was entitled “Characterizing Trawlable and Untrawlable Substrate Using Single Beam Echo Sounder Data to Improve Estimation of Commercial Groundfish Abundance” (by Rooper, Mark Zimmermann, and Michael Martin) (.pdf, 549KB). This poster described ongoing efforts by RACE biologists to classify seafloor substrate as trawlable or not trawlable using seabed acoustic backscatter collected during RACE trawl surveys. The analysis used characteristics of the shape of echoes returned from the seafloor and classification tree analysis to determine trawlability of substrate in the Aleutian Islands. The method shows promise for classifying substrate as it modeled trawlability at three transects with >90% acccuracy and was able to predict trawlability at a test dataset with 75% accuracy.

Rooper also presented a different poster at the 50th Anniversary Symposium of the American Institute of Fisheries Research Biologists held 13-15 February in Seattle. This poster was entitled “An ecological analysis of rockfish (Sebastes spp.) assemblages in the north Pacific along broad-scale environmental gradients” (.pdf, 379KB) and described an assemblage analysis of Gulf of Alaska (GOA) and Aleutian Island (AI) bottom trawl data collected on rockfish species in Alaska. The analysis used an index of overlap of species and age groups along environmental gradients to determine differing distributions of rockfish throughout Alaska. The analysis identified four major groups of rockfish separated by both depth and location along the Alaska coastline (a deepwater group in Southeast Alaska, a deepwater group in the central GOA and AI, as well as a mid-depth group in each location).
 

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