POLLOCK RESOURCES IN THE CENTRAL BERING SEA
2003 The demersal component of the stock is usually assessed during bottom trawl surveys while pelagic component is studied using acoustic surveys (Karp and Wallers 1994). It was stated by numerous surveys that usually demersal orientation is more common for older fish, and younger fish are more dis...
| Main Authors: | , , , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.151.8098 http://www.afsc.noaa.gov/REFM/CBS/Docs/8th%20Annual%20Conference/S&T%20Comm%20Report%202003%20Attachment%206.pdf |
| Summary: | 2003 The demersal component of the stock is usually assessed during bottom trawl surveys while pelagic component is studied using acoustic surveys (Karp and Wallers 1994). It was stated by numerous surveys that usually demersal orientation is more common for older fish, and younger fish are more distributed in midwater. Simultaneously conducted bottom trawl and acoustic surveys could give new data to estimate the stock and to compare different ages vertical distribution. The surveys were conducted simultaneously in the same area of the North-West part of Bering Sea near cape Navarin from October 28 to November 4, 2002. Acoustic data were collected in the whole water column using EY500 Simrad echosounder on the board of Japanese trawler KA YE- MARU N228. The trackline consisted of 448 nautical miles (Fig. 1). The following a specialized complex of the equipment and the software was used for the echo survey:. echo sounder EY500 Simrad (38 kHz) with single beam antenna in the towed body;. PC, used as the block of management and monitor of echo sounder;. GPS receiver of firm Trimble Navigation (USA), connected to the computer of the echo sounder and automatically determining coordinates of a vessel |
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