UK Commercial Fishing Methods Explained

Commercial fishing methods: what this guide covers

Commercial fishing catches fish and shellfish for sale. Recreational sea angling uses rods and lines for sport or personal enjoyment. Some equipment shares basic principles, but commercial nets, vessels and operating procedures are not instructions for recreational anglers. This guide explains the main gear families described by Seafish, with a focus on UK waters and selected fisheries supplying the UK. It is not a guide to obtaining permission, licences or quotas.

Demersal and pelagic fishing explained

Demersal fishing targets species living on or near the seabed. Pelagic fishing targets fish in the water column. These terms describe where fish are caught, not a sustainability certificate. A demersal fishery may use a trawl, a net, a line or a trap. Pelagic fish may be caught with a midwater trawl, a purse seine or a line. Local conditions and target species influence the gear used.

Seine nets: using ropes and netting to gather fish

A seine brings fish into an enclosing net. In demersal boat seining, long ropes are set around an area and retrieved so that fish are guided towards the net. Seafish describes anchor or Danish seining, Scottish seining and pair seining. The way the ropes and net are deployed distinguishes these methods. Purse seining is a different surrounding-net method and should not be confused with demersal seining.

Purse seine fishing: enclosing a shoal

A purse seine surrounds a shoal of fish. A line running through rings along the lower edge is drawn in, closing the bottom of the enclosure before the catch is brought aboard. This method is associated with schooling fish in the water column. Catch selectivity depends on the shoal being targeted and how the gear is used; surrounding a shoal does not guarantee that every animal inside is the intended catch.

Beam trawling: a rigid frame holds the net open

A beam trawl uses a rigid beam or frame to maintain the horizontal opening of a towed net. Supports and ground gear allow it to work close to the seabed. Designs vary with the target species and the ground being fished. Seafish describes developments intended to reduce drag, seabed contact or unwanted catch. Those developments should not be treated as proof that every beam-trawl fishery has the same environmental performance.

Demersal trawling: nets towed near the seabed

A demersal trawl is towed on or close to the seabed. In an otter trawl, trawl doors spread the gear horizontally, while the headline and ground gear shape the opening. Fish pass towards the cod-end, where the catch is retained. Pair trawling uses two vessels to spread a net, and multi-rig arrangements use more than one net. Mesh dimensions, escape panels and other design choices affect which animals are retained. Bottom contact and unwanted catch must be considered in the context of the particular fishery.

Pelagic trawling: fishing in the water column

A pelagic trawl operates in midwater rather than being designed to work on the seabed. It may be towed by one vessel or a pair. Seafish describes how fish-finding equipment helps crews locate shoals and position the gear. Operating away from the seabed changes the type of habitat contact, but does not eliminate questions about bycatch or the condition of the target stock.

Gill nets, tangle nets and trammel nets

Gill nets are panels of netting in which fish can become held around the gill region. Tangle nets are rigged to entangle their catch. A trammel net combines layers of netting so that an animal passing through the larger outer mesh can become caught in a pocket of the finer inner mesh. Net dimensions and rigging influence the catch. Set nets and drift nets differ in how they are positioned or allowed to move; neither term alone describes the full design or environmental impact.

Longlining, handlining, jigging and pole-and-line

A longline carries a series of hooks attached to a main line. Demersal longlines work near the seabed, while pelagic longlines operate in the water column. Handlines are worked directly, and jigging uses moving lures or hooks to attract a response. Pole-and-line fishing is another hook-and-line method covered in the source. Seafish includes examples outside UK waters, so these methods should not all be presented as equally widespread in the UK fleet. Hook-and-line gear is not automatically free from unwanted catch.

Pots and traps: catching shellfish and other species

Pots and traps encourage animals to enter an enclosure from which escape is more difficult. Baited pots are used for species such as crab, lobster, whelk and Nephrops, with designs suited to the target animal. Seafish also describes cuttlefish traps and fixed fish traps. Pots may be linked together and marked with surface buoys. Trap construction, openings, deployment and retrieval influence the catch; lost gear remains a concern.

Scallop dredging and other dredges

A dredge gathers animals from the seabed into a collecting structure. Scallop dredges differ from trawl nets and should be described separately. Their contact with the bottom is central to how they work. Assessing their effect requires information about the seabed habitat, gear design and fishing activity, rather than relying on the name of the method alone.

Comparing commercial fishing gear

The clearest first comparison is between gear that is actively moved through an area and gear that is set for animals to encounter. Trawls, dredges and seining are active methods; set nets, longlines and pots commonly involve deployment followed by retrieval. A second comparison is between fishing near the seabed and fishing in the water column. Neither comparison provides a universal ranking of sustainable seafood.

Bycatch and selective fishing gear

Bycatch is catch outside the intended target, including unwanted species or unsuitable sizes of the target species. Selective gear aims to change what is retained, for example through mesh design, escape panels or other modifications. The result depends on the species present and the way the gear is operated. Sustainability also requires consideration of stock condition, fishing pressure, habitat effects and management. No method should be labelled sustainable solely because it uses hooks, traps or a particular net.

Lost fishing gear, ghost fishing and marine litter

Lost or abandoned fishing gear can continue trapping animals: this is often called ghost fishing. Seafish also explains that discarded gear can create hazards and contribute to marine litter. Maintenance and responsible handling of worn gear are therefore relevant alongside catch selectivity. The source discusses end-of-life gear management, but its dated statistics and policy descriptions are not presented here as current UK requirements.

Training, safety and current commercial fishing rules

This is an educational overview, not professional advice or operational training. Commercial fishing involves equipment and vessel hazards that require appropriate training and supervision. This page does not authorise the use of any gear or establish current fishing rights, quotas, closure areas, minimum sizes or technical rules. Check the responsible fisheries authority for the relevant waters and activity before relying on a legal requirement.

Source and further reading

Based on Seafish, Basic Fishing Methods, written by Mike Montgomerie. The uploaded document contains 110 PDF pages and explains commercial fishing gear, including examples beyond the UK. Read the original publication at https://www.seafish.org/document/?id=35572 or https://www.seafish.org/media/bwabfkkj/basic-fishing-methods.pdf. This Tackl overview is newly written from the source facts; no source illustrations or pages have been republished. It is not endorsed by Seafish and is not a statement of current fishing law.