Nature Conservation Advice from NatureScot and JNCC: Demersal Fisheries Management Plans

Executive Summary

This advice forms part of a commission from the Marine Directorate (MD) to NatureScot and JNCC to provide nature conservation advice to support the development of UK Fisheries Management Plans (FMPs). The advice provides information on the risks arising from the Scottish fisheries contained within the Atlantic Cod FMP, the Atlantic Haddock FMP, the Northern Shelf Cod FMP, the North Sea Whiting FMP, the North Sea and West Coast of Scotland Haddock FMP, the North Sea and West Coast of Scotland Megrim FMP, the North Sea and West Coast of Scotland Monk/Angler FMP, the North Sea and West Coast of Scotland Saithe FMP, the Northern Shelf Hake FMP, the Northern Shelf Ling FMP, and the West Coast of Scotland Whiting FMP, hereafter referred to as the Demersal FMPs, to:

• The designated features of Marine Protected Areas (MPAs) in Scottish waters
• Priority Marine Features (PMFs)
• UK Marine Strategy (UK MS) descriptors

This advice sets out our approach and a brief assessment of risks to MPA features, PMFs and UK MS descriptors in Scottish waters from the fisheries covered in the demersal FMPs. Although the underlying impact pathways are similar (e.g. bycatch is a risk in all three assessments), there are also important differences. The UK MS and PMFs list cover a much broader range of species than those protected by MPA designations, especially for cetaceans and fish. Also, the underlying objectives are different for each and therefore there may be subtle but important differences to the assessment of risk and precaution. Therefore, our advice is presented separately for MPA features, PMFs and UK MS descriptors.

This initial advice has scoped in otter trawls, pair trawls, beam trawls, and demersal seines - collectively referred to as demersal trawls and seines - as well as static nets targeting monk/anglerfish and longlines targeting hake, identifying them as the most relevant gear types for consideration. More specific information on gear types, location and fishing effort would improve the ability to assess environmental risks associated with each FMP and may alter some of the risk-ratings presented. However, the primary aim of this advice is to provide a pragmatic steer on where the greatest concerns lie for interactions between the relevant fishing gear types, the designated features of MPAs, PMFs, and UK MS descriptors.

Risks relating to the designated features of MPAs in Scottish Waters

Fisheries included in the Demersal FMPs have the potential to impact the designated features of MPAs in three primary ways;

(i) through the bycatch of designated features of MPAs

(ii) the direct (targeted) and indirect (bycatch) removal of prey species on which designated species depend, and

(iii) physical impacts to seafloor resulting in alterations to habitat feature or supporting habitat condition.

These impacts can potentially occur both inside and outside MPA site boundaries.

Assessments of the impact of fishing activity occurring within MPAs in Scottish waters has been carried out by the Marine Directorate of the Scottish Government. Management measures for relevant fishing activities within MPAs have been implemented or are in development, to ensure any fishing within MPAs is compatible with the MPA’s conservation objectives. Therefore, the existing assessment and management pathways mitigate risks arising from fishing activity within Scottish MPAs, and no additional action is suggested for the Demersal FMPs within Scottish MPA site boundaries at this time. Pressures occurring within MPA sites have therefore been screened out of this advice. However, potential risks to designated mobile species from bycatch and removal of prey species may remain when they move outside of the MPA.

The results of an initial consideration of the available evidence and expert opinion of the main risks arising from the Demersal FMPs to the designated features of Scottish MPAs are summarised below.

Risk Summary:

While the risk to the conservation status of mobile species that are designated features of MPAs through bycatch from demersal trawls and seines is generally considered low, given the broad scale of the demersal fisheries covered in this assessment and the significant gaps in the available evidence, the risk rating for bycatch in demersal trawls and seines is assessed as moderate. Certain fish species such as the basking shark and flapper skate as well as several deep-water fish species, including elasmobranchs, may be at greater risk owing to their life histories. Continued or enhanced monitoring and research has the potential to improve our understanding of risk and is essential for directing management in relation to these more sensitive species.

Static nets and longlines, primarily associated with the hake and anglerfish fisheries, present a considerable bycatch risk for birds and other mobile species which are designated features of MPAs in Scottish waters. Bycatch in static nets is considered the greatest threat to harbour porpoise, and the primary source of bycatch mortality among seals. Gillnet fisheries pose a significant bycatch risk to diving seabirds such as common guillemots, razorbills, and European shags. There are also concerns about the seabird bycatch in the Scottish and UK offshore longline fisheries, with fulmars being particularly vulnerable to bycatch in this gear type. Based on current evidence, the risk rating for bycatch in static nets and longlines is considered high. A continuation of current monitoring effort, supported by enhanced data collection and research to fill gaps is required to understand the scale of the problem and improve the ability to assess risk. This risk may be revisited in future as the evidence base develops.

Juvenile gadoids are an important component of the diet for a variety of marine predators and are thus considered a key forage fish species. Forage fish are essential to marine food webs, often serving as the primary food source for higher trophic levels, including marine mammals and seabirds. Harbour porpoise, for example, are known to predate heavily on juvenile gadoids. Given the breadth and scale of fisheries included in the Demersal FMPs, it is likely, either through targeted fishing, bycatch or downstream impacts on spawning and recruitment, that there will be a reduction in the availability of juvenile gadoids and other prey species to marine predators designated within the Scottish MPA network. Recognising a potential impact pathway but lacking sufficient evidence to provide a confident conclusion, we advise that the risk of prey depletion to designated features of MPAs from demersal fisheries be considered moderate. Certain fisheries are likely to present a great risk than others, but further work is needed to help disentangle these risks.

Risks relating to Priority Marine Features

Priority Marine Features (PMFs) in Scotland represent a selection of habitats and species identified for their conservation importance. These eighty-one features are acknowledged for their national significance and the role they play in supporting marine biodiversity. The list includes highly mobile marine mammals and fish, as well as habitats and benthic species of conservation interest. The purpose behind identifying PMFs is to focus conservation efforts, guide management actions, and ensure the protection and enhancement of marine biodiversity within Scottish waters.

The primary impacts pathways for PMFs are the same as those listed above for MPA features: (i) targeted commercial catch, bycatch, (ii) prey reduction, and (iii) physical impacts to the seafloor.

The results of an initial consideration of the main risks to PMFs also echo the assessment for MPA features, albeit covering an additional suite of features. In addition, we consider physical impacts to the PMF benthic features and habitats. The results of our assessment are summarised here.

Risk Summary:

In addition to the bycatch risks outlined for MPA designated species above, demersal trawls and seines covered by the Demersal FMPs present a further bycatch risk for all listed fish species, including several long-lived species with an increased vulnerability to bycatch mortality. For listed fish which are also commercial stocks, risks of bycatch may be mitigated through their own stock management processes, but significant gaps in the available evidence remain. Risks for PMF marine mammals are likely to echo the risks outlined above for MPA features. The risk rating for bycatch in demersal trawls and seines is assessed as moderate. Continued monitoring and enhanced data collection and research to address knowledge gaps may allow us to reassess this risk in future.

Risks relating to longlines are downgraded from the MPA feature assessment above as the PMF list does not currently include birds, which are the most vulnerable group in terms of bycatch in this gear. However, monitoring of commercial species bycatch, including sensitive fish and elasmobranch PMF species is limited in Scottish longline fisheries and further research is needed to understand the risk to these species. Therefore, a moderate risk rating is proposed for bycatch of PMFs in longlines.

The potential impact of static nets echo those proposed above for MPA features (bycatch of marine mammals and fish), as such the risk rating for bycatch of PMFs in static nets is assessed as high.

Owing to a potential impact pathway but lacking sufficient evidence to provide a confident conclusion, we advise that the risk of prey depletion to PMFs from demersal fisheries be considered moderate.

As the benthic species and habitat PMFs are also represented across the Scottish MPA network, these features will be offered some protection through the MPA management process. Further work to identify and mitigate impacts on the 11 most sensitive benthic and habitat PMFs in inshore waters is also ongoing. Therefore, some of the physical impacts likely to affect the national status of PMFs will be mitigated, and the risk rating for physical impacts to benthic and habitat PMFs from demersal trawls and seines is assessed as moderate. The risk to these PMFs from demersal trawls and seines will vary depending on the intensity of the fishing pressure and the sensitivity of the individual PMF to that pressure. Physical impacts from static demersal gears are likely to represent a lower risk to benthos but there may be areas where high intensity static fishing can have a moderate impact on PMF habitats and benthic features through physical disturbance. Recommendations for further work with respect to physical impacts of demersal fisheries are highlighted below under the assessment of risk for GES descriptor D6 “seafloor integrity”.

Risks relating to UK Marine Strategy Descriptors

The UK Marine Strategy Regulations 2010 (SI 2010/1627) provide the policy framework for delivering marine environmental policy at the UK level and set out how the vision of clean, healthy, safe, productive, and biologically diverse oceans and seas will be achieved. The Regulations require authorities to define the characteristics of Good Environmental Status (GES) and in turn develop an associated Programme of Measures to deliver GES. Good Environmental Status (GES) establishes a ‘benchmark’ for our seas which seeks to ‘protect the marine environment, preventing its deterioration and restoring it where practical, while allowing sustainable use of marine resources.’ For each descriptor there are a number of practical targets and indicators that facilitate assessment of our delivery against each descriptor.

The UK Marine Strategy Regulations require management action to be taken to achieve or maintain GES. The Fisheries Act (2020) enables regulators to deliver on this ambition through the Ecosystem Objective, which states that fish and aquaculture activities should be managed using an ecosystem-based approach, which is, in-part, defined in the Act by the achievement of GES. Equally, the recently published Joint Fisheries Statement (2022) lays out the ambition across UK administrations to take action to achieve or maintain Good Environmental Status (GES) in all UK waters (Joint Fisheries Statement, 2022).

This advice focuses only on the most relevant descriptors in terms of risks posed by commercial and recreational fisheries: D1 biodiversity, D3 commercial fish and shellfish, D4 food webs, D6 seafloor integrity and D10 marine litter. In the UK MS, these descriptors are assessed using indicators for each of their constituent ‘ecosystem components.’ This is carried through to this advice resulting in advice on risks to eight descriptor-ecosystem component combinations: D1, D4 cetaceans; D1, D4 seals; D1, D4 seabirds; D1, D4 fish; D4 food webs; D1, D6 seafloor integrity and D10 Marine Litter.

The results of an initial consideration of the available evidence and expert opinion of the main risks arising from the Demersal FMPs to UK MS Descriptors are summarised below.

Risk Summary:

There is a moderate risk to achieving GES for the biological biodiversity of seals, due to impacts from demersal fishing activities. Although bycatch in static nets is a significant source of mortality for seals, and demersal fisheries may reduce the availability of prey, at their current scales these pressures are not thought to be among the primary drivers for change with respect to achieving GES for seals. However, there are still significant gaps in the available evidence and research is ongoing to understand the drivers of seal population dynamics in Scotland and the UK. As a result, the FMP risk rating is assessed as moderate. Continued monitoring and enhanced data collection and research to address knowledge gaps may allow us to reassess this risk in future.

There is a high risk to achieving GES for the biological biodiversity of cetaceans and birds, due to impacts from demersal fishing activities. This rating is primarily driven by risk of bycatch in static net and longline fisheries for cetaceans and birds, respectively. Continued monitoring and enhanced data collection and research to address knowledge gaps may allow us to reassess or improve the geographical specificity of this risk rating in future.

There is a high risk to seafloor integrity due to benthic disturbance caused by mobile demersal fishing activities. However, due to data availability, this risk is assessed only based on data collated across the >12m UK mobile demersal fishing fleet. It does not include impacts from static gears; while these are likely to be lower risk, these gears have the potential to significantly impact seafloor integrity if operating at a high intensity. Further work is needed to disentangle and quantify impacts from individual fisheries covered by this generic advice.

There is a moderate risk of impacts from marine litter. More robust estimates of abandoned, lost, or discarded fishing gear in the fishery are required.

Recommendations

The detailed advice, upon which this summary advice is based, also makes recommendations for the Demersal FMPs to reduce associated risks to the designated features of MPAs in Scottish waters (arising from fishing activity outside site boundaries), PMFs, and achievement of GES (UK MS); these include:

• A recommendation to undertake additional targeted evidence collection to improve estimates of bycatch of marine mammals, seabirds, and designated fish for demersal gear types, utilising remote electronic monitoring where appropriate.
• Strategic work at a broad geographic scale is required to understand the relative impact to seafloor integrity from each fishery covered by the Demersal FMPs and identify opportunities to reduce/remove risk and understand trade-offs across the UK fishing fleet.
• For demersal fish stocks that serve as key prey species in the marine food web, implement an enhanced ecosystem-based fisheries management approach that:

1. Identifies these important prey stocks and evaluates utilising ecosystem data and models to ensure their long-term sustainability and role in the ecosystem.

2. Assesses whether current management measures maintain adequate population levels of these prey stocks to meet the needs of dependent predators like larger fish, marine mammals, and seabirds.

3. Analyses how alternate management strategies could impact predator productivity and food web resilience through effects on the availability of these prey species.

4. Engages stakeholders early in developing interdisciplinary, pragmatic solutions that incorporate ecosystem considerations and balance ecological requirements with other objectives through evaluating potential trade-offs.

This enhanced ecosystem approach for managing key demersal forage species aims to contribute to achieving Good Environmental Status while reflecting both the requirements for human use and the need for a healthy marine ecosystem.