Results 201 to 210 of about 32,183 (242)

Characterization of River Herring Bycatch in the Northwest Atlantic Midwater Trawl Fisheries

North American Journal of Fisheries Management, 2014
Abstract In the U.S. northwest Atlantic, the incidental catch of river herring (Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis) by midwater trawl vessels targeting Atlantic Herring Clupea harengus and Atlantic Mackerel Scomber scombrus has become a concern for river herring conservation.
N. David Bethoney, Kevin D. E. Stokesbury, Bradley P. Schondelmeier, William S. Hoffman, Michael P. Armstrong   +4 more
openaire   +2 more sources

Hydrodynamic characteristics of frustum-type depressor for sampling midwater trawl

Ocean Engineering
Zhiqiang Liu, Fuxiang Hu, Rong Wan, Yucheng Wang, Shaojian Guo, Hao Yan, Cheng Zhou   +6 more
openaire   +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

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 ...
Kresimir Williams, Chris D. Wilson, John K. Horne   +2 more
openaire   +1 more source

The effect of artificial illumination on Chinook salmon behavior and their escapement out of a midwater trawl bycatch reduction device

Fisheries Research, 2019
The Pacific hake (Merluccius productus) midwater trawl fishery is the largest groundfish fishery off the U.S. West Coast by volume. Catches comprise mainly Pacific hake, however, bycatch of Chinook salmon (Oncorhynchus tshawytscha) can be an issue ...
Mark J. M. Lomeli, W. Wakefield
semanticscholar   +1 more source

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

Problem scientific basis equal strengthe construction of cable-net part of the midwater trawl

, 2020
The article outlined the R&D activities that would create a theory and methodology for designing the uniform strength cable-net mid-water trawls. To manage the mentioned problems a large volume of research is needed, however, the transition to cable-net
M. Rozenshtein
semanticscholar   +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   +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

Assessing prey fish populations in Lake Michigan: comparison of simultaneous acoustic-midwater trawling with bottom trawling

Fisheries Research, 1997
Abstract The Lake Michigan fish community has been monitored since the 1960s with bottom trawls, and since the late 1980s with acoustics and midwater trawls. These sampling tools are limited to different habitats: bottom trawls sample fish near bottom in areas with smooth substrates, and acoustic methods sample fish throughout the water column above ...
Mary C. Fabrizio, Jean V. Adams, Gary L. Curtis   +2 more
openaire   +1 more source