Midwater trawling is

trawling Trawling is an industrial method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch di ...

, or net fishing, at a depth that is higher in the

water column The (oceanic) water column is a concept used in oceanography to describe the physical (temperature, salinity, light penetration) and chemical ( pH, dissolved oxygen, nutrient salts) characteristics of seawater at different depths for a defined ...

than the bottom of the ocean. It is contrasted with

bottom trawling Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and Demersal zone, demersal trawling. Benthic tra ...

. Midwater trawling is also known as

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

trawling and bottom trawling as

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

trawling. In midwater trawling, a cone-shaped net can be towed behind a single boat and spread by trawl doors, or it can be towed behind two boats (

pair trawling Pair trawling is a fishing activity carried out by two boats, with one towing each wikt:warp, warp (the towing cables). As the mouth of the Fishing net, net is kept open by the lateral pull of the individual vessels, Bottom trawling#Otter trawlin ...

) which act as the spreading device. Midwater trawling catches

pelagic fish Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs. ...

such as

anchovies An anchovy is a small, common forage fish of the family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water. More than 140 species are placed in 1 ...

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

tuna A tuna (: tunas or tuna) is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae ( mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bul ...

and

mackerel Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment. ...

, whereas bottom trawling targets both bottom living fish (

groundfish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They oc ...

) and semi-pelagic fish such as:

cod Cod (: cod) is the common name for the demersal fish genus ''Gadus'', belonging to the family (biology), family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gad ...

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

halibut Halibut is the common name for three species of flatfish in the family of right-eye flounders. In some regions, and less commonly, other species of large flatfish are also referred to as halibut. The word is derived from ''haly'' (holy) and ...

and rockfish. Whilst midwater trawling does not damage the seafloor (like

), the method is not perfectly selective and results in relatively high levels of discards of unwanted catches.

References

FAO The Food and Agriculture Organization of the United Nations; . (FAO) is a List of specialized agencies of the United Nations, specialized agency of the United Nations that leads international efforts to defeat hunger and improve nutrition ...

Fisheries
''Midwater Pair Trawls''

External links

{{fisheries and fishing Fishing equipment Fishing industry

See also

References

External links