Results 111 to 120 of about 267 (147)

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 ...
Krešimir Williams, John K Horne
exaly   +2 more sources

A method for easing the launch and recovery of mouth-closing midwater trawls

Deep-sea Research, 1977
Abstract A method is described to simplify the handling of mouth-closing midwater trawls during launch and recovery operations at sea. The vertical cables of the net mouth are drawn upward to stack the mouth and frame bars into a smaller package.
Bruce H Robison
exaly   +2 more sources

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.
exaly   +3 more sources

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

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

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

The Influence of an Electric Light on the Capture of Oceanic Cephalopods by a Midwater Trawl

Journal of the Marine Biological Association of the United Kingdom, 1998
A total of 57 comparative hauls using a rectangular midwater trawl with a fishing mouth area of 50 m2 (RMT 50) were carried out along the sides of an imaginary triangle south of Madeira in 1986. A total of 1258 cephalopods were caught, giving a mean of 22 per haul with a range from 0 to 67.
Malcolm R. Clarke, P.L. Pascoe
  +6 more sources

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

Development of a low-energy midwater trawl with different combinations of trawl nets and trawl doors through model experiments

Fisheries Science, 2018
Greenhouse gas (GHG) emissions from fisheries are of primary concern because of their effects on the environment. GHG emissions from fisheries are mainly related to their fuel consumption. Furthermore, the fuel consumption of fisheries also influences their economics. Therefore, many studies have been conducted to find ways of reducing fuel consumption
Jihoon Lee, Chun-Woo Lee, Songho Park, Jieun Kim, Subong Park, Taeho Kim   +5 more
openaire   +1 more source

Application of a fuzzy controller to depth control of a midwater trawl net

Fisheries Science, 2000
SUMMARY: A control system is presented that uses a fuzzy algorithm in controlling the depth of a midwater trawl net, and field experiments carried out on the training ship Kaya of Pukyong National University. The fuzzy controller calculates the length of the warp to be changed, based on the depth error between the desired depth and actual depth of ...
Chun-Woo Lee, Ju-Hee Lee, In-Jin Kim
openaire   +1 more source