Three Pelagic Fisheries Management Plans - Strategic Environmental Assessment (SEA)

3. Environmental Baseline

Summary of the Current State of the UK Marine Environment

Section 3 provides a summary of the current state of the UK marine environment for each of the environmental issues screened into this SEA, and where applicable their associated UK MS descriptors (Table 4; Annex 1). The SEA has been conducted against the environmental baseline set out in these sources of existing information. We acknowledge that there are some uncertainties and evidence gaps in the environmental baseline. However, we consider that this environmental baseline provides a comprehensive level of information to undertake an effective assessment and provide informed evidence-based recommendations. Where required, further detailed assessments using additional evidence will be completed ahead of the implementation of FMP actions.

It is likely that without the proposed FMPs, those issues which are contributing to the current state of the marine environment will likely continue to have an influence. The proposed FMPs seek to promote the management of the fisheries in a more coherent and coordinated manner that considers wider environmental issues. The FMPs therefore have the potential to improve the current state of the environment set out below, both where no improvement has been observed, and where positive trends have been identified. Section 6 and 7 considers how the implementation of the FMPs’ proposed policies and actions could change the baseline.

Biodiversity, Flora and Fauna

The primary source of information on the current state of the UK marine environment came from the UK MS descriptor status assessments: The updated UK Marine Strategy Part 1, published in 2019. The impact of fishing has been considered as part of the assessment on the UK MS descriptors, therefore information on the impact of fishing activity on the marine environment has been included in the sections below as part of the baseline. For further information on the baseline related to UK MS descriptors see Appendix B.

Cetaceans (whales and dolphins) are an important marine ecosystem component that contributes to overall levels of biodiversity (D1). In addition, as top predators, the abundance of cetaceans can also provide some understanding on how the food web is functioning (D4).

The current status of cetaceans for both the North Sea and Celtic Sea is mixed. While there are some aspects that are in line with the achievement of GES, much of the picture is unclear. The impact of various net fisheries is leading to bycatch that, in places, might be impacting long term population viability of harbour porpoise.

Other than for a limited number of coastal bottlenose dolphin populations, it is unclear whether the abundance and range of most cetacean species can be considered in line with GES. Fisheries and the removal of prey species is one of several activities / pressures that have the potential to result in changes in cetacean abundance and distribution.

Seals are an important marine ecosystem component that contributes to overall levels of biodiversity (D1). In addition, as top predators, seal productivity can also provide some understanding and insight as to how the food web is functioning (D4).

Grey seal populations and productivity continues to increase, and targets are being met. Bycatch (largely in tangle / trammel nets) is occurring but not at levels that threaten population viability. For harbour seals, the status is not in line with GES where population declines have occurred in some areas. The cause is unknown. It is not thought to be linked to bycatch as occurrences are rare and there is no indication that it is linked to other pressures associated with fishing.

Seabirds are well monitored species that are an important marine ecosystem component that contributes to overall biodiversity (D1). In addition, as top predators, the abundance of birds can also provide some understanding and insight as to how the wider food web is functioning (D4).

Seabird populations are currently below the level that is considered to meet GES and the situation is deteriorating. Some declines in breeding success have been linked to prey availability caused by climate change and / or past and present fisheries. Invasive predatory mammals are also known to impact breeding success on island colonies. The impact of bycatch will be included in future assessments and current evidence suggests that some longline and static net fisheries could be having possible population level impacts on certain species.

Fish are an important ecosystem component that contributes to overall levels of biodiversity (D1). In addition, fish of different species have a significant role in marine food webs (D4), acting as both predators and prey. Some fish species are commercially exploited, and only a proportion of these have managed quotas. Over-exploitation can lead to a decline in stocks (D3) which can reduce both future commercial opportunities and have wider ecological impacts.

The current status of fish communities in the UK is primarily shaped by historical over-exploitation by fisheries, while ongoing over-exploitation continues to be a notable contributing factor. Improved fisheries management since the 1990s has resulted in more stocks being fished at or below MSY levels, so although the target is not yet met, there is a positive trend. Improved fisheries management has also resulted in some positive trends in fish communities beyond the targeted stocks.

Food webs (D4) are the network of predator-prey relationships that occur in the marine environment, from phytoplankton to top predators such as birds or seals. Fish communities are a key component of food webs. Knowledge of food webs allow understanding of how changes at one trophic level can impact those above and below it.

Historic fishing activity which has contributed to the current environmental baseline has had a large impact on fish community structure - a key component of marine food webs. With improved fisheries management focusing on stocks, some recovery is occurring. However, the management of fish stocks solely to safeguard future fisheries will not necessarily lead to all food web targets being met. Changes in plankton are likely driven by prevailing environmental conditions, but other impacts cannot be ruled out.

Water Quality

Marine litter, including from fishing activities, is a significant pressure on marine ecosystems and water quality. The UK has not yet achieved its aim of GES for litter. Beach litter levels in the Celtic Seas have remained largely stable since the assessment in 2012, whilst beach litter levels in the Greater North Sea have slightly increased. Waste fishing material is a component of beach litter. Both floating litter and seafloor litter remain an issue, with plastic the predominant material. Achieving GES for marine litter requires improved waste management practices, the reduction of lost or discarded fishing gear, and increased awareness and monitoring of the issue.

Underwater noise from fisheries, while not the primary source, can still contribute to the overall noise pollution in the marine environment. Fishing vessels will contribute to underwater noise through sonar, engine noise, gear interacting with seabed and deploying and retrieving gear.

The achievement of GES for underwater noise in the UK is uncertain. Research and monitoring programmes established since 2012 have provided an improved understanding of the impacts of sound on marine ecosystems. However, achieving GES for underwater noise will require better understanding and monitoring of the issue, as well as the development and implementation of strategies to manage noise pollution from various sources.

Climatic Factors

Climate change impacts are not part of the UK MS, therefore evidence from other sources were used to provide baseline information in relation to this issue. Statistics from the Department for Energy Security and Net Zero (DESNZ) (formally known as Department for Business, Energy & Industrial Strategy (BEIS), Department for Transport (DFT) and Engelhard et al (2022) report on Carbon emissions in UK fisheries, were used to identify the contribution UK fishing fleets have to the total carbon emissions at sea each year.

Vessel Emissions

The fishing sector contributes to greenhouse gas emissions primarily through fuel use by fishing vessels, the use of refrigerants, and the transport and distribution of seafood products (Engelhard et al., 2022^[4]). At UK level, fuel use from all fishing activity contributed an estimated 467 kt CO₂e in 2024—representing around 0.12% of total UK territorial emissions (378 Mt CO₂e) and 0.43% of domestic transport emissions (109 Mt CO₂e), and equivalent to about 1.1% of agricultural emissions (41.0 Mt CO₂e).

Pelagic fishing vessels typically have higher daily fuel consumption than many other fishing fleet segments, reflecting the scale of their operations and the distances travelled during fishing trips. Daily fuel consumption in the pelagic fleet accounts to around 17% of total emissions at fleet segment (Metz et al., 2022^[5]). Despite the relatively high fuel use of pelagic vessels, when emissions are assessed per unit of landed output (e.g. edible protein), pelagic species have high catch volumes relative to fuel use and, generally, have comparatively lower emissions than most other seafood (Sandison et al., 2021^[6]).

Although horse mackerel and greater silver smelt are present in UK waters, the stocks are of relatively limited economic importance to UK fisheries and UK ports. A significant proportion of UK horse mackerel catches are landed outside the UK.

Despite a relatively small contribution to UK fishing activity, consideration of emissions reduction and fuel efficiency remains relevant as part of wider efforts to support a sustainable, economically viable and climate-resilient fishing sector.

Climate change impacts on Pelagic FMP stocks and fisheries

Climate change is expected to affect the three stocks covered by these FMPs to varying degrees. Horse mackerel, as a pelagic species, is particularly responsive to changes in sea temperature and prey availability. Evidence from the North Sea and wider Northeast Atlantic indicates that climate change is already influencing horse mackerel populations, with implications for stock productivity, ecosystem functioning and fisheries management (Lavín et al., 2007^[7]; AZTI, 2023^[8]; Fuentes-Pardo et al., 2023^[9]). In addition to direct climate impacts, climate-driven changes in plankton communities and prey availability may also influence growth, recruitment and distribution of horse mackerel.

For North Sea and West of Scotland greater silver smelt, the available evidence base is more limited. As a deep-water, cold-affinity species, it may be particularly sensitive to environmental changes affecting deeper marine habitats and may respond differently to climate-driven environmental change than more resilient pelagic stocks (Rose, 2005). Its association with deep benthic habitats may limit the availability of suitable refuges as environmental conditions change. Current projections remain uncertain due to the lack of species-specific evidence.

Cultural Heritage

The definition of the ‘marine and aquatic environment’ in the Fisheries Act 2020 (section 52) includes features of ‘archaeological or historic interest in marine or coastal areas’. These features should be regarded as part of the wider marine environment.

Cultural heritage impacts are not part of the UK MS, therefore evidence from other sources were used to provide baseline information in relation to this issue.

The Fishing and the Historic Environment report produced by Historic England was used as the primary source of information on the interactions between commercial fishing and the marine historic environment.

The report identifies several potential and evidenced interactions between commercial fishing and marine heritage assets. Both positive and negative interactions can arise when archaeological material present on the foreshore and seabed is encountered during commercial fishing. Of relevance to the Pelagic FMP fisheries, the report finds that pelagic towed gear, mid‐water trawls and purse seines are unlikely to encounter marine heritage assets and therefore interactions are not anticipated, except for incidental gear loss, and it is anticipated that interactions with cultural heritage assets are not likely to be a significant issue for the Pelagic FMPs. Given the anecdotal nature of many of these interactions a comprehensive assessment of the extent of interactions and their impacts, is currently not available in UK waters.

In Scotland Historic Marine Protected Areas (HMPAs) are marine historic assets of national importance which survive in Scottish territorial waters (out to 12 miles offshore) that are protected by law. Further information and datasets on Scotland’s Marine historic environment and cultural heritage can be found at Historic environment and cultural heritage | Scotland's Marine Assessment 2020.

The historic environment map viewer for Northern Ireland provides an overview of historic sites and landscapes.

Existing Environmental Effects of Pelagic Species Fishing

The draft Pelagic FMPs focus on achieving the sustainable harvesting of stocks. This focus seeks to reduce the environmental risks linked to over-fishing these stocks, thereby giving positive benefit to environmental status.

Nevertheless, fishing within sustainable limits for the target stocks (MSY) may reduce but will not eliminate some of the negative impacts of that fishing activity on the wider marine environment. These impacts are identified in the sections below.

As described in Section 2, this Environmental Report focuses on assessing how the policies and actions in the draft Pelagic FMPs are likely to give rise to both significant positive and negative environmental effects. More detailed fisheries assessments which consider current activity are already in progress or have been completed. These assessments may be used to inform the FMPs’ actions as they are delivered, and include:

• The Marine Directorate’s offshore MPA fisheries assessments programme and ongoing inshore MPA and PMF fisheries assessment programmes.
• Defra’s Revised Approach to fisheries management programme (inside twelve nautical miles) in England.
• The Marine Management Organisation’s (MMO) ongoing Fishery Assessment programme (outside twelve nautical miles) in England.
• Assessments required to prepare the Marine Protected Areas (Prohibited Methods of Fishing) Regulations (Northern Ireland) 2022 which came into operation on 1 January 2023. Further fisheries measures are being drafted for 3 offshore MPAs and will be consulted on later this year.
• The wider marine environment (UK MS) assessments

Nevertheless, this ER acknowledges the likely significant effects associated with fishing activity being managed through the draft Pelagic FMPs and sets out in broad terms how the FMP will seek to avoid, reduce, or at least mitigate significant negative effects.

Environmental Effects Associated with MPAs

Advice provided to fisheries policy authorities by Statutory Nature Conservation Bodies (SNCBs) gives more detail on the risks associated with fishing for species covered by the Pelagic FMPs in relation to the designated features of MPAs, Priority Marine Features (PMFs) for Scotland and UK Marine Strategy Descriptors (UK MS). Joint advice from JNCC and NatureScot, commissioned by the Scottish Government's Marine Directorate and covering Scottish waters, was received for Pelagic FMPs in Scottish waters as part of a single assessment. Additional joint advice from Natural England and JNCC, commissioned by Defra and covering English waters, was received for the draft North Sea greater silver smelt FMP and North Sea horse mackerel FMP,

Inside the boundaries of Scottish MPAs, the Marine Directorate assess human activities that could interact with the designated features of MPAs, seek the advice of SNCBs and introduce management where required. Stakeholders have worked closely with regulators to help develop measures to mitigate impacts within inshore and offshore MPAs. Therefore, appropriate management is either in place already (for offshore MPAs) or will be introduced soon to ensure any fishing within MPAs is compatible with the MPA’s conservation objectives. Current management measures already in place related to the use of bottom towed gear is detailed at MPA monitoring strategy - Marine environment.

In England the assessments of the impact of fishing activities inside MPAs are undertaken by the IFCAs within 6nm and the MMO outside 6nm. Stakeholders have worked/will work closely with regulators to help develop measures to mitigate impacts within inshore and offshore MPAs. Appropriate management is or will be in place to ensure any fishing within MPAs is compatible with the MPA’s conservation objectives. Current management measures already in place are detailed on the MMO and Association of IFCAs websites.

In Northern Ireland, current fisheries management measures exist for nine inshore MPAs through The Marine Protected Areas (Prohibited Methods of Fishing) Regulations (Northern Ireland) 2022. Further fisheries measures have been consulted on for three offshore MPAs (South Rigg MCZ, Queenie Corner MCZ and Pisces Reef SAC). The consultation closed on 24th August 2026 and the analysis report will be available in due course.

Whilst MPA site management considers fishing activity that occurs within the site’s boundaries, there remains the potential for fishing activity occurring outside an MPA to still have impacts on the features protected within the MPA. These impacts can happen when either the pressure exerted by the fishery impacts protected features beyond the spatial footprint of a particular fishing activity (e.g. noise) or when the feature of an MPA is mobile and travels outside the site.

The key risks of fisheries contained within the Pelagic FMPs relating to the designated features of MPAs in Scottish and English Waters are summarised below.

Environmental effects associated with designated features of MPAs (Scottish waters)

Fisheries contained in the Pelagic FMPs have the potential to impact the designated features of MPAs in 2 primary ways;

(i) through the bycatch of designated features of MPAs, and

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

Evidence suggests that pelagic trawl and purse seine fisheries pose a relatively low risk to MPA designated marine mammal and fish species features in terms of bycatch, with limited records of bycatch of harbour porpoise, grey seals, basking shark and ‘common’ skate. However, due to low sampling effort, improved evidence is needed to support a low-risk rating for these species. Several MPA designated bird species features are considered sensitive to bycatch in these fisheries; guillemot, razorbill and cormorant have all been recorded as bycatch in pelagic trawls.

While mobile species are typically considered sensitive to bycatch in static and drift net fisheries, there is insufficient resolution to determine the impact of pelagic drift net fisheries specifically. There are no (or very limited) pelagic drift nets used in the regions covered by the three FMPs, however, based on the potential sensitivity to bycatch, expert advice suggests the risk ought to be classed as moderate. This aligns with the assessment from French et al. (2022).

Owing to significant gaps in the available evidence, the risk rating for bycatch in pelagic fisheries is considered moderate. Addressing evidence gaps through ongoing monitoring and research or, where necessary, through enhanced data collection will improve confidence in the assessment of bycatch risks.

All the fish species managed through the pelagic FMPs are considered prey species for a broad range of predators and as such, are an important part of the marine ecosystem around Scotland. There is good evidence to demonstrate that many of the pelagic species covered in the pelagic FMPs are key prey for many of the designated fish, marine mammal, and seabird features in Scottish MPAs. However, the extent to which features rely on specific pelagic prey species is less clear. As such, the risk rating for pelagic fisheries in Scottish waters regarding removal of important prey species that designated species depend on is considered moderate. Work done by the Pelagic FMPs to ensure fisheries meet the precautionary and stock sustainability objectives of the Fisheries Act will help to ensure that exploited stocks are fished sustainably, but additional consideration of predator needs is recommended.

Risks relating to the designated features of MPAs (English waters)

The main impacts of the fisheries incorporated in the relevant Pelagic FMPs on the designated features of MPAs arising from fishing activity outside MPA site boundaries, with an indication of their risk level, are summarised below:

• There is a moderate risk of bycatch of mobile species that are designated features of MPAs in pelagic trawls, demersal trawls, ringnets, and purse seines for GSS and horse mackerel.
• There is a low risk to the designated features of MPAs through of bycatch of mobile species in handline fisheries for GSS.
• There is a moderate risk to the designated species of MPAs from reductions in their prey through the targeted horse mackerel fishery.
• There is a low risk to the designated species of MPAs from reductions in their prey through the targeted greater silver smelt fishery.

Environmental effects associated with UK MS Descriptors (Scottish waters)

Advice provided to fisheries policy authorities by the SNCBs gives more detail on the key risks to UK MS descriptors arising from horse mackerel and greater silver smelt fishing and their likely impact on achieving Good Environmental Status (GES) (Appendix A). The following potential issues and their associated risk level have been identified for mackerel, horse mackerel, herring, blue whiting and greater silver fishing on UK MS descriptors:

There is a moderate risk to achieving GES for the biological diversity of cetaceans, seals, and birds, due to impacts from pelagic fishing activities. Bycatch is likely to impact some species populations to the extent that it is contributing to the failure to achieve GES. However, though mobile species are typically considered sensitive to bycatch in static and drift net fisheries, there is insufficient resolution to determine the impact of pelagic drift net fisheries specifically. There are no (or very limited) pelagic drift nets used in the regions covered by the three FMPs, however, based on the potential sensitivity to bycatch, expert advice suggests the risk ought to be classed as moderate. It is thought that pelagic gears are contributing relatively little to the failure of this indicator in relation to bycatch. However, owing to the importance of pelagic stocks within the Scottish marine ecosystem, the potential to impact prey availability needs further consideration for pelagic fisheries. The Fisheries Management Plan (FMP) process presents an opportunity to further strengthen the ecosystem-based approach to fisheries management. This can help deliver the Ecosystem and Sustainability Objectives, maintaining target fish populations in a favourable condition while also contributing to the achievement of Good Environmental Status.

There is a moderate risk to marine litter. More robust estimates of abandoned, lost, or discarded fishing gear from pelagic fisheries are required.

Risks relating to UK Marine Strategy descriptors (English waters)

Previous work by Natural England investigating the impact of the pressures associated with the fishing industry across all 11 descriptors of Good Environmental Status (GES)^[10] in the UK marine environment has highlighted 6 key issues^[11]. Of these issues, only a subset will be relevant to any particular fishery / sector.

The main interactions between the draft Pelagic FMPs and UK MS Descriptors that have been identified are summarised below. The high-level assessments flag the potential risk based on the predominant gear types used across a range of fisheries.

• There is a moderate risk to D1, D4 cetaceans, D1, D4 seals, D1, D4 seabirds through bycatch in pelagic trawls, demersal trawls, purse seines, and ringnets.
• There is a low risk to D1, D4 cetaceans, D1, D4 seals, D1, D4 seabirds through bycatch in handline fisheries.
• There is a moderate risk to D1, D4 cetaceans and D1, D4 seabirds through targeted removal of horse mackerel, an important prey species.
• There is a low risk to D1, D4 seals through targeted removal of horse mackerel.
• There is a low risk to D1, D4 cetaceans, D1, D4 seals, D1, D4 seabirds through targeted removal of greater silver smelt.
• There is a high risk to D1, D6 seafloor integrity from demersal trawls
• There is a moderate risk to D10 marine litter from pelagic trawls, demersal trawls, purse seines, and ringnets.

Environmental effects associated with Scottish Priority Marine Features (Scottish waters only)

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 (but not seabirds), 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 impact pathways for PMFs are the same as those listed above for MPA features: (i) bycatch, and (ii) prey reduction. As with the MPA risk assessment, physical impacts have been screened out as pelagic gears are considered low risk with respect to this impact pathway.

There is a moderate risk of bycatch for PMFs (marine mammal and fish) from pelagic fisheries in Scottish waters. As discussed above for MPA features, pelagic fisheries are not expected to pose a substantial risk of bycatch; however, evidence gaps remain resulting in a precautionary rating. Addressing evidence gaps through ongoing monitoring and research or, where necessary, through enhanced data collection will improve confidence in the assessment of bycatch risks.

Several marine mammal and fish PMFs, in addition to those species designated as MPA features, are likely to utilise pelagic species at various life stages as a prey resource. Though they exhibit a variety of foraging strategies, many killer whale groups, including those that visit Scottish waters, are fish-eating specialists, feeding almost exclusively on schooling pelagic fish species such as herring and mackerel. Fin whale feed on small schooling fish species such as herring and sprat. Herring and mackerel are also important prey species for adult porbeagle. Though substantial evidence gaps exist, many of the species targeted by fisheries listed under the Pelagic FMPs are important prey species for a variety of cetaceans and fishes, including species of conservation interest which are not listed as PMFs, such as the humpback whale; thus, a moderate risk to PMFs (fish, marine mammals) through removal of key prey species in pelagic fisheries is concluded.

Work done by the FMP to ensure fisheries eventually meet the precautionary and sustainability objectives of the Fisheries Act will help to ensure the stocks are fished sustainably, but additional consideration of predator needs is recommended. For forage fish stocks, additional steps should be considered so that stocks are managed in such a way as to enable them to perform their key role in marine food webs and ecosystems. This would be an important step in implementing an Ecosystem Based Approach to Fisheries Management.

Climatic Factors

Vessels fishing for horse mackerel and greater silver smelt contribute to the total carbon emissions at sea each year by the UK’s fishing fleets. While the estimated emissions by the UK fishing fleet represents a small proportion of the overall emissions in the UK, decarbonising the fleet and moving towards net zero will help reduce the contribution of fisheries activities to climate change.

No conclusive evidence is currently available on the impact of fishing activity for horse mackerel and greater silver smelt fishing on organic carbon stocks and the impacts will depend on the gears used to target these pelagic stocks now and in the future.

Cultural Heritage

Fishing activity can have both positive and negative effects on marine heritage assets. The positive effects relate to the discovery of marine heritage assets during fishing activity, with both past and future discoveries or findspots often reliant on fishing gear interactions. Negative effects can be caused by physical disturbance to cultural heritage on and within the seabed. Specific effects include: impeded access and interpretation of assets by fishing gear (for example nets, lines and ropes) collecting around physical structures; direct damage of assets by gear, usually towed gear, causing irreparable alteration to physical structures; burial of archaeological material by sediment during fishing practices; removal of the archaeological material from the seabed during fishing practices; and transferal of archaeological material from its original place on the seabed during fishing practices. Avoiding negative interactions with marine heritage assets will help conserve them for their enjoyment by future generations.

The marine historic environment also plays an important role in providing ecosystem services in relation to nature conservation, sea angling, recreational diving and commercial fishing. Marine heritage assets, particularly ship and plane wrecks can provide habitats for marine life, with fish often aggregating around them for refuge or to feed. Avoiding negative interactions with marine heritage assets that act as habitats can positively contribute to the conservation of the wider marine environment.