Results 141 to 150 of about 430 (170)

Walleye pollock (Theragra chalcogramma) behavior in midwater trawls

Fisheries Research, 2013
Abstract Trawls are standard tools for surveying fisheries resources, yet they are selective in what they retain, and thus provide potentially misleading information about fish populations. In order to evaluate the potential for selective retention in a midwater survey trawl used in conjunction with acoustic surveys of walleye pollock, fish behavior ...
John Horne, Krešimir Williams
exaly   +2 more sources

Depth control of a midwater trawl gear using fuzzy logic

Fisheries Research, 1995
Abstract This paper describes the model of a simplified trawl system and the design of a control system that uses a fuzzy algorithm in controlling the depth of a midwater trawl net. The practicality of the control system was examined using computer simulation.
exaly   +2 more sources

A Simple Surface-Midwater Trawl

Progressive Fish-Culturist, 1968
Charles R. Gasaway, Victor W. Lambou
exaly   +2 more sources

Diving Plane for a Tucker Midwater Trawl

Progressive Fish-Culturist, 1983
exaly   +2 more sources

Simple Closing Midwater Trawl for Small Boats

North American Journal of Fisheries Management, 1989
Abstract A closing midwater-trawl system for a small boat (7 m) was developed to apportion hydroacoustic population estimates among fish species by collecting vertically stratified limnetic fish samples. These stratified samples could also be used for providing biological data on the fish or for feeding and behavior studies.
Hermann J. Enzenhofer, Jeremy M. B. Hume
openaire   +1 more source

A new electronic system for the rectangular midwater trawl (RMT)

Marine Biology, 1990
This paper describes a modified modern version of the original rectangular midwater trawl (RMT) manufactured by the Institute of Oceanographic Sciences (IOS). The shipboard acoustic transducer and the underwater RMT-monitor were replaced by an electronic interface box was while the data transfer, realized by a single-conductor cable.
W. Dimmler, H. Klindt
openaire   +3 more sources

Avoidance and escape behaviour by herring encountering midwater trawls

Fisheries Research, 1997
The main objective of this study was to assess how and to what extent Baltic herring avoid and escape midwater trawls under commercial fishing conditions. Information was obtained by acoustic, visual and direct sampling techniques. The majority of herring schools in the path of an approaching trawl were observed to enter the trawl.
Suuronen, Petri, Lehtonen, Esa, Wallace, John   +2 more
openaire   +1 more source

Modeling of a midwater trawl system with respect to the vertical movements

Fisheries Science, 2000
SUMMARY: A mathematical model of the midwater trawl system is presented to aid in understanding the dynamic behavior. The equations of motions for the trawl system have been obtained using Lagrange's equation with respect to variables of the displacement of the trawler, the length of the warp connecting the trawler and otter board, the angle of the ...
Chun-Woo Lee, Ju-Hee Lee
openaire   +1 more source

Behaviour of Herring Schools in Response to a Midwater Trawl

Journal of the Fisheries Research Board of Canada, 1968
not available
openaire   +1 more source

Quantification of water flow and net drag in midwater trawls

Fisheries Research, 1993
Abstract The flow velocity and hydrodynamic drag of 18 quarter-scale midwater box trawl nets were quantified in a circulating water channel using electromagnetic current meters and strain gauges, with the mouth of each net attached to a rigid pipe frame to maintain geometric similarity.
Buxton, N. G., DeAlteris, J. T.
openaire   +2 more sources