Midwater trawl
Midwater trawl
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The picture shows the relative size of a pelagic trawl and a trawler in the oceanic redfish fishery. Fully extended, the opening of the trawl may be 23,000 square meters which equals roughly the size of five football fields.
Location of effort with midwater trawl in 2008 (hours trawling), dark areas indicate highest effort Source: The Marine Research Insitute |
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Midwater trawl catch (t) by species Source: Statistics Iceland, weight reports
Midwater trawl catch (t) by month Source. Statistics Iceland, weight reports |
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Midwater or Pelagic trawls are the principal fishing gear used in oceanic redfish and blue whiting fisheries, but they are also increasingly used alongside purse seines for capelin and herring. In its present use it is a very large type of fishing gear and commonly referred to also as a "gloria trawl". It operates without touching the bottom and is frequently trawled at depths of a few hundred metres in the redfish fishery, where the minimum mesh size in the cod end is 135-155 mm, depending on fishing area. The meshes get increasingly larger as they are closer to the opening, where they are commonly 64 metres. The opening of the net can be up to 23,000 m2, the size of 5 football fields. The trawls used for capelin, herring and blue whiting are of the same construction but have a smaller mesh size in the cod end or 21 mm for capelin and 40 mm for herring and blue whiting. A recent development, especially in the blue whiting fisheries, is for two vessels to share one trawl and divide the catch.
The first use of midwater trawls in Icelandic waters took place in 1952 for catching cod on the spawning grounds. When the EEZ was extended to 12 miles and Icelandic trawlers were excluded from this zone, this fishery came to an end. Midwater trawls were then not really used again in Icelandic waters until the oceanic redfish fisheries began in 1982.
References and further information
References (Gunnarsson et al. 1998), (Þór 2005)
For full citation and further information on fishing gear see this page.
Hörður Sævaldsson / Hreiðar Þór Valtýsson University of Akureyri
