Underwater observations on fish behavior to determine the coefficient of catchability for Danish seine

Underwater observations were conducted to assess the impact of the research Danish seine elements on behavior of walleye pollock Theragra chalcogramma in its active zone. The underwater video equipment was installed on specially designed and constructed experimental platform and on elements of the D...

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Bibliographic Details
Published in:Izvestiya TINRO
Main Author: Ivan V. Roy
Format: Article in Journal/Newspaper
Language:Russian
Published: Transactions of the Pacific Research Institute of Fisheries and Oceanography 2016
Subjects:
Online Access:https://doi.org/10.26428/1606-9919-2016-187-233-244
https://doaj.org/article/2cf5cf31b4d2419facf386c135470b30
Description
Summary:Underwater observations were conducted to assess the impact of the research Danish seine elements on behavior of walleye pollock Theragra chalcogramma in its active zone. The underwater video equipment was installed on specially designed and constructed experimental platform and on elements of the Danish seine. In the experiment with pollock, the experimental platform demonstrated its low efficiency, however, it could be used for observations on sedentary benthic organisms on homogeneous soils without sharp changes in the terrain. With the equipment installed directly on the Danish seine, high efficiency of the seine ropes was observed: up to 92 % of fish from encircled volume remained in the towed area. Taking into account this estimation and features of fish biomass distribution, the coefficient of catchability for Danish seine is determined as 0.40 ± 0.15.