Trawl towed in midwater by one vessel to target pelagic fish
Pelagic trawling is a method of towing a trawl at any point in the water column between the surface and seabed. It is generally used to target shoaling species such as mackerel, herring and sprats.
The beginnings of pelagic trawling come from demersal trawling where they tried to make a large net and tow it between two vessels (pair trawling) and lift it off the seabed. Gradually the mouth of the trawl was made bigger by the inclusion of large meshes in the mouth of the trawl. With the advancement of underwater acoustic technology by the military in the way of echo sounders and sonars and the adoption of this into the fishing industry it became possible to find shoals of pelagic fish and set the nets at the correct height with in the water column to catch these species. The introduction of lightweight curved trawl doors and the use of acoustic measurement sensors on the trawl enabled the new design pelagic trawls to be towed by one vessel as a single trawl. Nowadays much of the pelagic trawling activity, both single and pair trawl, is done by modern powerful vessels equipped with state of the art electronics to find and track the shoals of pelagic fish. However throughout the UK and EU there are many smaller scale pelagic fisheries undertaken by smaller less sophisticated vessels.