Scotland’s Future Catching Policy: selectivity proposals 2026

Gillnets are bottom set nets typically deployed along the edge of the continental shelf, usually in pursuit of monkfish or hake, using monofilament nylon nets that are set on the seabed. The net is held to the seabed by a weighted ‘foot-rope’ and held up by a floating ‘head line.’

This fleet segment comprises of approximately six fishing vessels in Scottish waters, of which two are Scottish registered vessels and four are UK registered.

Gillnets are designed to be selective and the size of mesh and the length of ‘soak time’ is specific to the species being targeted and is governed by detailed legislation:

• Bottom set gillnets used for hake are required to have a mesh size of at least 100mm and no more than 100 meshes deep and a maximum length of 25km per vessel - the maximum soak time for these is 24 hours;
• Entangling nets used for directed fishing for monkfish are required to have a mesh of at least 250mm and no more than 15 meshes deep, and a maximum length of 100km per vessel - the maximum soak time for these is 72 hours.

Fish smaller than the mesh size are able to pass through unharmed, and those larger than the mesh are deflected away (except in the case of tangle nets). Fish of the correct size are selected as their heads fit through the mesh, and they are then caught by the gills (hence the name gill net).

The way in which gill nets are constructed varies depending on the main target species and local conditions. In general, fixed nets employ a heavily weighted footrope and have a few floats on the headrope so that the bottom of the net rests firmly on the seabed and the net forms a loose, upright wall. Each net is attached to an anchor weight or stake to prevent the net moving with the current, or both ends are marked with a buoy. This can vary however:

• Drift nets are allowed to move freely with the current and therefore have more floats on the headrope and a very lightly weighted footrope. In Scotland, it is prohibited to have on board or deploy one or more driftnets the individual or total length of which is more than 2.5 km.
• If the nets are set on a headrope with a large amount of slack netting, fish are more likely to become entangled without being properly enmeshed, such configurations are often known as tangle nets.
• The trammel net is another type of static gear which is classes as an enmeshing net. This is also based on a loosely hung hill net, but it has additional walls of very large meshed ‘armouring’ hung on one or both sides.

Sensitive species considerations

The UK gillnet fleet is currently monitored under the UK Bycatch Monitoring Programme (UK BMP). Bycatch reported through the programme includes seals, harbour porpoise, common dolphin, and diving birds such as cormorants, shags and guillemots. To date, much of the monitoring effort has been directed to the south west of England where bycatch risk to these species is higher as nets are set predominantly in shallow inshore waters, with lower level monitoring in Scottish waters.

Monitoring is also underway in the tanglenet fishery targeting crawfish and which operates in waters adjacent to the Outer and Inner Hebrides. This will help improve understanding of potential bycatch risk in this seasonal fishery.

Mitigation measures that have been developed or are being trialled to reduce sensitive species bycatch in the gill net fleet include pingers, net modifications, visual deterrents, and specifications on depth of net setting. Trials of some of these measures are ongoing through the CIBBRiNA project and Clean Catch UK. Specific measures in relation to cetacean bycatch include that fishing vessels 12m and over in length  use Acoustic Deterrent Devices (pingers) in specific areas for the purpose of reducing cetacean bycatch. These areas are as follows:

• Area IV and the net’s mesh size is 220 mm or
• Area IV and the net is of any mesh size and is 400 metres or less
• Area VII d, e, f, g, h and j.