Scotland's Future Catching Policy: Selectivity Proposals Consultation 2026

6. Mitigating Bycatch of Sensitive Marine Species

Incidental bycatch or entanglement of marine species in fishing gear is a threat to the conservation and welfare of sensitive marine species, including cetaceans, seabirds, seals, turtles and sharks. In the UK, bycatch monitoring programmes estimate that thousands of these animals are accidentally caught each year. Monitoring programmes are predominantly focused on UK-flagged vessels, whereas knowledge of bycatch in international-flagged vessels is limited. Such incidental events not only have a negative impact on the animal concerned, but can cause considerable distress to fishers, as well as significant costs in terms of lost or damaged gear.

The UK administrations have a range of commitments through domestic, and International law to address the incidental catches of sensitive marine species. To meet these obligations, the Scottish Government has historically worked in partnership with the UK Government and the other devolved administrations, as well as independently, to take forward research and monitoring to improve our understanding of bycatch in UK waters and to implement action working in partnership with the sector, to reduce the numbers of sensitive marine species captured incidentally in fisheries.

There is currently a requirement under fishing vessel licence conditions for all fishing vessels operating in UK waters to report any bycatch (incidental mortality or injury) of marine mammals to the Marine Management Organisation (MMO) within 48 hours of the end of the fishing trip.^[16] The MMO coordinate the collection of this data on behalf all UK adminstrations and the reporting form and associated guidance can be found here: https://www.gov.uk/guidance/marine-mammal-reporting-requirements.

Reporting is necessary to comply with international standards for the conservation of marine mammals, and to allow continued export of fisheries products to the United States. Reporting also helps to assist conservation efforts in mitigating marine mammal bycatch. No enforcement action will be taken as a result of reporting where the injury, mortality, or bycatch reported has occurred within the course of legal fishing practices. There is no such requirement to report bycatch of seabirds or other sensitive marine species. As of August 2025, no marine mammal bycatch has been reported in Scottish waters to the Marine Management Organisation.

Questions for this section:

Q18: Do you think that the current reporting process is easy to follow?

Q19: If not, what could reduce barriers to reporting?

Q20: If a fisher were to experience a marine mammal bycatch incident, do you feel that this fisher could confidently report this incident without fear of negative repercussions to themselves personally or to their wider fleet?

Q21: is there anything that could increase trust in the reporting system, noting that reporting is a legal requirement?

Q22: Do you think the current bycatch reporting requirement should be extended to include seabirds?

6.1 Longline fleet segment

Longline fishing is the use of long, usually suspended, lines equipped with baited hooks which are deployed from a series of buoys. After ‘soaking’ for several days, these are then hauled in and the individual fish are removed, usually by hand, from the hooks and the hooks are rebaited and redeployed. This method of fishing is very selective and yields a very high quality of catch. However, there are issues with incidental sea bird mortality as they target the bait on the hooks as the gear is deployed or the catch as the lines are hauled.

This fleet segment comprises of approximately 10 over 10m fishing vessels in Scottish waters who use demersal long lines as their primary method of fishing.^[17].

a) What do we have now?

• The longline fleet is currently monitored under the UK BMP.
• As of November 2021, there is a mandatory requirement under fishing vessel licence conditions for all fishing vessels operating in UK waters to report any bycatch (incidental mortality or injury) of marine mammals within 48 hours of the end of the fishing trip. There is no such requirement to report bycatch of seabirds. As of May 2025, no marine mammal bycatch has been reported to the MMO for this fleet.
• There is currently no legal requirement to deploy mitigation measures in the fishery in UK waters. However, some mitigation measures are used voluntarily by vessels fishing in Scottish waters (e.g. bird scaring lines).

b) What needs to change?

• From data gathered through the UK BMP, bycatch of seabirds, which includes Northern fulmar, Northern gannet, great skua and great shearwater is of greatest concern in this fleet segment^[18]. A great deal of work has been carried out in partnership with the fleet, which has invested significant effort to develop and trial practicable and effective mitigation measures.
• This has included development of bird scaring lines, or ‘streamers’, which are brightly coloured lines that are towed from the vessel, over the area where the baited hooks are deployed to deter birds from entering that area. They are considered an effective method and can significantly reduce bycatch in some fisheries. Trials are at an advanced stage where several stages of practicality testing have been carried out to produce technical specifications for streamers that are both practicable and long enough to protect the length of line at which seabirds are most vulnerable to bycatch. Efficacy testing is now underway in partnership with the fleet. Practicality trials of other mitigation methods, such as altered sinking regimes, are also ongoing.

c) What are we proposing will change?

• Introduce a requirement to use bird scaring lines
• Promote best practice measures for reducing sensitive species interactions, including measures such as offal management and night setting.

d) What the end result will be?

• Enhancing mitigation of seabird bycatch by moving voluntary measure into mandatory requirement

Questions for this section:

Q23: Do you agree with the proposed measures set out above for longlines to reduce sensitive species bycatch?

Q24: Are there other measures that you think should be included as best practice, or that require further trialling?

6.2 Gillnet fleet segment

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^[19].

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^[20]. 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.

Questions for this section:

Q25: Are you aware of any evidence or studies on sensitive species bycatch in Scottish gillnet fisheries outside of those mentioned above (monitoring through the BMP and in the Outer and Inner Hebrides tanglenet fishery)?

Q26: Are there any measures that you think could improve understanding or knowledge regarding bycatch in gillnet fishing?

6.3 Pots and Creels fleet segment

a) What do we have now?

• This fleet segment comprises of approximately 1023 fishing vessels in Scottish waters, which use pots and creels as their primary method of fishing*. Of this, 892 are inshore and 131 are offshore (outside the 12nm line).
• Inshore potters and creelers consist of 848 Scottish registered vessels and 44 UK registered vessels.
• Offshore potters and creelers consist of 98 Scottish registered vessels, 29 UK registered and 4 non-UK vessels^[21].
• Best practice guidance for the creel fishery^[22] to reduce the incidence of entanglement of minke whales and basking sharks.
• The Outer Hebrides Inshore Fisheries Pilot included a number of management measures and provided fishers with an app which could record marine mammal entanglement.

b) What does the evidence say about what needs to change?

• The main species reported entangled in creel gear are minke whales, basking sharks and humpback whales, although entanglements involving leatherback turtles, harbour seals, grey seals, smaller whales, dolphins and porpoises have also been recorded^[23].
• The study by the Scottish Entanglement Alliance (SEA) published in 2021 analysed strandings data collected by the Scottish Marine Animal Strandings Scheme (SMASS) from between 2005 and 2019. Analysis of the strandings data showed that 32 cases between 2015 and 2018 were identified to have been entangled in rope consistent with creel fishing. Strandings data collected by SMASS between 2019 and 2025 found that 54 cetaceans were shown to exhibit injuries consistent with general fishing gear entanglement during this timeframe, as well as 9 grey seals, 1 harbour seal, 4 basking sharks and 1 blue shark. Cetacean species recorded were humpback whales, minke whales, Sowerby’s beaked whale, Risso’s dolphin, killer whale, dolphin species, short-beaked common dolphin and sperm whale.
• Although injuries consistent with entanglement were observed, it cannot be said for certain in all cases which type of gear the entanglement was caused by, or if this was the cause of death.
• SEA also interviewed over 150 creel fishers about their experience of entanglements. The results of all the information combined resulted in estimates of around 30 minke whales and 6 humpback whales becoming entangled in creel gear in Scottish waters each year; these entanglements mostly occurred in floating groundlines^[24].
• The SEA study suggested that although entanglements are rare at an individual vessel level the combined numbers for the whole creel fleet are substantial.
• Trials carried out by SEA of creel fleets using sinking groundline rather than floating found that most fishers encountered very few problems with re-roped fleets, in some cases preferring them to gear made up with floating groundlines^[25]. These trials also showed the sinking rope lay lightly on the seabed with minimal movement.

c) What are we proposing will change?

• Continue to support and promote the use of sinking groundline
• Look at ways to incentivise the use of sinking groundline

d) What the end result will be?

• Supporting the use of sinking groundline should help to reduce the entanglement of whales and basking sharks by decreasing interaction with gear as the groundline will sit gently on the seabed rather than floating in loops in the water column which increases entanglement risk.
• Further uptake of this gear type – specifically in areas where it has been found to be very practical to fish with – could be highly beneficial to the ecosystem without negatively impacting fishing operations.

Questions for this section:

Q27: Do you agree that creel vessels should trial sinking groundlines?

Q28: Do you think creel fishers should be incentivised to use sinking instead of floating line?

Q29: What do you think are the barriers to using sinking groundlines?