Commercial fishery for razor clams using electric current gear - consultation: strategic environmental assessment report

6. Assessment

The assessment is grouped by SEA objective which were determined following feedback from statutory consultees during scoping for this assessment, and where relevant within these we break down our assessment of likely significant effects in each SMR.

6.1 Biodiversity, Flora and Fauna

6.1.1 Outcome can be implemented while protecting PMFs and meeting conservation objectives of MPAs, SACs and SPAs where relevant.

In relation to the scientific trial, we sought advice from NatureScot at the outset, and again when the trial was extended. In both cases we received advice that indicated where some fishing could be authorised without compromising the integrity of the MPA network, and other areas where further assessment was required. We have responded to that advice in various ways:

• Closing areas to fishing pending appropriate assessment under the Habitats Regulations;
• Revising trial area boundaries to remove areas where fishing activity and conservation objectives were incompatible;
• Using remote electronic monitoring (REM) to verify vessels were fishing in authorised areas and taking appropriate administrative action to breaches of terms and conditions

We do not know with certainty what a commercial fishery may look like in terms of number of vessels, area access and other technical measures, should this be the consultation outcome. The consultation seeks views on all of these areas. We would further utilise advice of our fisheries scientists in determining the appropriate scale of any potential fishery. We have confidence that approaches tested in the trial point the way to sustainable fishing without having significant adverse effects on the species and habitats in our MPA network or PMFs more widely.

We can expect a new trial, should this be a component of the consultation outcome, to be more limited in scale compared to the current trial. We may reasonably expect, given we would develop any new trial (or commercial fishery) with the advice of NatureScot, that the potential for a new trial to have significant adverse effects would be adequately controlled through appropriate siting, scale and management.

This assessment applies to all SMRs. We have found likely significant effects with the potential to disturb some seabird species during the trial in some areas, however we have been able to introduce measures that we consider reduce this risk below significant adverse levels and anticipate applying this type of method in either commercial fishery or new trial consultation outcomes.

In making these assessments we have used a variety of data sources, but recognise that data expressly gathered to assess effects of this potential fishery would be higher quality and allow a high confidence assessment. Better local level knowledge on the impacts of razor clam fishing on seabed fauna and prey availability would enable any potential commercial fishery to be appropriate in scale with reference to local environmental vulnerabilities and conservation priorities.

We summarise the anticipated effect on this objective for each broad consultation outcome in Table 13.

(Table 13) Effect of consultation outcomes on biodiversity, flora and fauna.

Consultation Outcome: Commercial fishery

Effect on objective: Level

Confidence: Moderate

Consultation Outcome: New Trial

Effect on objective: Level

Confidence: Moderate

Consultation Outcome: Prohibition

Effect on objective: Negative

Confidence: Moderate

We have moderate confidence in these effects. This is because we recognise there is value in further characterising effects of electric current on fish species, work that was planned for the trial but was not completed. We do know that electric current of the type used in the trial fishery has short, recoverable effects on some prey species^[4]. We do not know the extent of IUU fishing that may occur in the event of a full prohibition, but from previous experience we assess the direction of the effect to be negative.

6.2 Population and Human Health

6.2.1 Outcome does not increase the risk of consumption of unsafe food

In the trial, razor clam grounds have been classified through the Shellfish Harvesting Classification by Food Standards Scotland like any commercial shellfish harvesting activity. This has afforded regulatory access and oversight that was lacking before the trial. We would propose that it is preferable for the consultation to deliver an outcome that preserves this access.

As noted in the regional summaries, for the most part razor clam shellfish harvesting areas have received A grade classifications but on the occasions where the classification falls below this level, protocols must be adhered to so that the catch remains safe to eat.

We would expect that a consultation outcome leading to prohibition of commercial harvesting by any means would result in IUU fishing with unregulated sale of catches with increased risk to human health.

We summarise the anticipated effect on this objective for each broad consultation outcome in Table 14.

(Table 14) Effect of consultation outcomes on food safety.

Consultation Outcome: Commercial fishery

Effect on objective: Level

Confidence: High

Consultation Outcome: New Trial

Effect on objective: Level

Confidence: High

Consultation Outcome: Prohibition

Effect on objective: Negative

Confidence: Moderate

Commercial and scientific fishing are both covered by the same regulatory standards therefore we have high confidence these would continue to be met in either circumstance. We assess the loss of regulatory oversight with respect to IUU fishing to have an overall negative effect on this objective, notwithstanding activity to enforce a prohibition. We have lower confidence in this outcome as it is unclear the extent to which IUU fishing would occur in this scenario.

6.2.2 Outcome does not increase the risk of harm to workers

Fishing and any commercial diving are dangerous activities, however the trial has enabled regulatory access by the Health and Safety Executive as well as the Marine Directorate to ensure vessels, gear and working conditions meet necessary standards. We would propose that the consultation outcome should preserve compliance with regulations and maintain access for regulators in the interests of worker safety.

We would expect that a consultation outcome leading to prohibition of commercial harvesting by any means would likely result in IUU fishing with increased health and safety risk to workers, as this regulatory oversight would be diminished.

We summarise the anticipated effect on this objective for each broad consultation outcome in Table 15.

(Table 15) Effect of consultation outcomes on worker safety.

Consultation Outcome: Commercial fishery

Effect on objective: Level

Confidence: High

Consultation Outcome: New Trial

Effect on objective: Level

Confidence: High

Consultation Outcome: Prohibition

Effect on objective: Negative

Confidence: Moderate

Commercial and scientific fishing are both covered by the same regulatory standards therefore we have high confidence these would continue to be met in either circumstance. We assess that in the case of prohibition and the loss of regulatory oversight with respect to IUU fishing, this would likely have an overall negative effect on this objective, notwithstanding activity to enforce a prohibition. We have lower confidence in this outcome as it is unclear the extent to which IUU fishing would occur in this scenario.

6.3 Material Assets

6.3.1 Outcome ensures razor clam populations can be maintained at levels that can be sustainably fished in the long term

We have evidence from the trial that fishing activity can be managed sustainably through our published stock assessments. These are not applicable in every trial area and the evidence is summarised on a SMR basis here. The appropriate regional model for managing this fishery will be determined having considered consultation respondents views and with the advice of the Marine Directorate fisheries scientists.

Should there be a commercial fishery following consideration of consultation respondents views, this would be monitored in line with the Marine Directorate’s approach to inshore fisheries management. This is an area of work that is itself subject to further consultation.

6.3.1.1 Solway SMR

Razor clam fishing has been intermittent in this region (1-2 vessels when present), meaning that no stock assessment has been possible as data are insufficient to satisfy the vetting process we have established for our stock assessment method. Therefore while we have anecdotal reports of high numbers of razor clams in some areas, particularly Luce Bay, we do not have an estimate of fishing mortality. Landings per unit effort (LPUE^[5]) appears to have declined over time in the trial. We would therefore require further data to determine sustainable harvesting levels in this SMR.

6.3.1.2 Clyde SMR

Razor clam fishing activity (7-12 vessels annually) in this SMR has been through stock assessment and has fishing mortality estimated to be below the fishing mortality associated with the maximum sustainable yield. LPUE appears to have remained stable during the scientific trial. We would therefore expect limited commercial fishing at the kind of scale within the trial to be sustainable in the long term.

6.3.1.3 Argyll SMR

In Colonsay, Razor clam fishing activity (3-7 vessels annually) has been through stock assessment and has fishing mortality estimated to be below the fishing mortality associated with the maximum sustainable yield. Stock assessments in Gigha and Coll and Tiree have not been completed as insufficient data have been gathered to pass vetting. LPUE appears to have remained stable in all areas during the scientific trial, though a significant period without fishing existed in both Coll and Tiree and Gigha areas. We would therefore expect limited commercial fishing to be sustainable in the Colonsay area in the long term, but would require to study whether a stock assessment in this area had relevance to other areas, or whether it was necessary to gather more data to make this assessment in Gigha and Coll and Tiree.

6.3.1.4 Outer Hebrides SMR

In Broad Bay, Razor clam fishing activity (1-2 vessels annually) has been through stock assessment and has fishing mortality estimated to be below the fishing mortality associated with the maximum sustainable yield. Fishing effort has been too sparse to complete a stock assessment in Benbecula. LPUE appears to have slightly increased. We would therefore expect limited commercial fishing to be sustainable in the Broad Bay in the long term, but would require further data to make this assessment in Benbecula.

6.3.1.5 West Highlands SMR

Razor clam fishing has been intermittent in this region (1-4 vessels when present), meaning that no stock assessment has been possible as data are insufficient to satisfy the vetting process. Therefore we do not have an estimate of fishing mortality. Landings per unit effort (LPUE) appears to have been stable over time in the trial, however no fishing activity occurred in 2023-2025. We would therefore require further data to determine sustainable harvesting levels in this SMR.

6.3.1.6 Forth and Tay SMR

Razor clam fishing activity (4-5 vessels annually) in this SMR has been through stock assessment and has fishing mortality estimated to be below the fishing mortality associated with the maximum sustainable yield. LPUE appears to have remained stable during the scientific trial. We would therefore expect limited commercial fishing at the kind of scale within the trial to be sustainable in the long term.

6.3.2 Summary of effects on objective

We summarise the anticipated effect on this objective for each broad consultation outcome in Table 16.

(Table 16) Effect of consultation outcome on sustainable fishing.

Consultation Outcome: Commercial fishery – Solway

Effect on objective: Level

Confidence: Low

Consultation Outcome: Commercial fishery – Clyde

Effect on objective: Level

Confidence: High

Consultation Outcome: Commercial fishery – Argyll

Effect on objective: Level

Confidence: Moderate

Consultation Outcome: Commercial fishery – Outer Hebrides

Effect on objective: Level

Confidence: Moderate

Consultation Outcome: Commercial fishery – West Highlands

Effect on objective: Level

Confidence: Low

Consultation Outcome: Commercial fishery – Forth and Tay

Effect on objective: Level

Confidence: High

Consultation Outcome: New Trial

Effect on objective: Level

Confidence: Moderate

Consultation Outcome: Prohibition

Effect on objective: Negative

Confidence: Moderate

We base the assessment of effect on this objective on stock assessment work. In the case of the Clyde and Forth and Tay regions, this encompasses all trial areas and therefore we have high confidence in the assessed effect in these areas. In the Argyll and Outer Hebrides areas, we have stock assessments for some razor clam fishing areas but not others, therefore we have moderate confidence pending advice on how stock assessments should inform the scale of a fishery. In the Solway and West Highlands regions, fishing has been too sporadic to complete stock assessments, therefore we have low confidence in the assessed effect on this objective. We have moderate confidence in our assessment in relation to a new trial, as the nature of such a trial would depend on consultation respondent views. We have moderate confidence in our assessment that the effect would be negative in the case of prohibition, as we are unclear on the likely extent of IUU fishing and corresponding enforcement activity.

6.3.3 Outcome minimises waste and starts with circular economy uses for assets that are beyond their usable lifespan

All participants were established businesses in either fishing or commercial diving prior to the establishment of the trial. They are therefore required to comply with MARPOL regulations on prevention of maritime pollution, with regulatory oversight by the Maritime and Coastguard Agency. Vessels will be encouraged to join the KIMO Fishing for Litter initiative.

As a specialised fishing segment, we will encourage businesses to work with waste processors to identify suitable pathways to handle end of life electric current gear, and facilitate these discussions where we can help.

Food production is identified as a key sector for a roadmap in the Scottish Government’s draft Circular Economy Strategy, and we will identify ways this fleet segment can contribute positively to the goals identified in the roadmap when it is published.

We summarise the anticipated effect on this objective for each broad consultation outcome in Table 17.

(Table 17) Effect of consultation outcome on waste and circular economy.

Consultation Outcome: Commercial fishery

Effect on objective: Level

Confidence: High

Consultation Outcome: New Trial

Effect on objective: Level

Confidence: High

Consultation Outcome: Prohibition

Effect on objective: Negative

Confidence: Moderate

In the case of a commercial fishery or a new trial, we expect existing good practice and compliance with any new expectations arising from government strategy to be continued. We assess that in the case of prohibition, some IUU fishing activity would likely resume leading to a negative effect on this objective, but we are unclear on the scale of this.

6.4 Approach to Mitigation

We do not know the precise scale of fishing activity, should the consultation outcome be a commercial fishery or further scientific trial. This would be informed by consultation respondents views and scientific advice. We have estimated that it is likely that the scale would generally be similar to the current scale in the trial, though there may be some cases where activity could increase. Where assessment indicated increased fishing activity is considered to have a likely significant effect on the status of a protected species or habitat, the relevant assessment process appropriate to the specific designation would be followed. In the trial, some activity was identified as potentially risking some protected species and following a fisheries assessment, management measures were introduced with the goal of reducing this risk.

As razor clams occupy localised patches of abundance, the management measures introduced to reduce potential risk to protected species took the form of controls on when vessels could access particular areas. This ensured that vulnerable species (for example seabirds in the conservation and management advice of a Special Protection Area) could make use of habitat while also allowing trial activity to continue without bringing vessels and species into conflict for access.

The consultation seeks views on how our knowledge of razor clam stocks should be used to manage access to fishing opportunities and one option may be to adopt a strict approach of only permitting fishing where stock assessments have been completed. Alternatively, the approach may be to require stock assessments as soon as practicable if seeking to fish areas where these have not been completed during the trial. These are intended to mitigate the risk of overexploitation.

6.5 Cumulative Effects

Seabed habitat that contains razor clam beds may be used by static gear fishing businesses targeting other shellfish, which may be a source of gear conflict. For the most part, mobile gear fishing targeting other shellfish species is separated from razor clam grounds by depth and substrate type. Therefore while razor clam fishing represents additional fishing activity in an area, it is not considered to materially change overall fishing pressure.

In some trial areas, offshore renewable infrastructure construction has occurred in areas inhabited by razor clams. When this has been the case, razor clam fishing has been limited by exclusion zones around construction vessels, and anecdotal reports have been received that the visual environment is too difficult for divers to work in following marine works such as jet trenching. Therefore other plans in the marine space may influence activity of this plan on temporary and permanent bases.

6.6 Reasonable Alternatives

The Scottish Government considers a commercial fishery using electric current to be the most rational next step for fishing for razor clams in Scotland. However we recognise that there will be diversity in views among consultation respondents and therefore we consider the following alternatives. We further invite views from respondents on alternatives that we may not have considered in the consultation document.

6.6.1 No commercial fishery

We have outlined the likely environmental effects of this alternative in Section 5.

6.6.2 A commercial fishery using conventional gear

Respondents may disagree with the Scottish Government view and advocate instead for a commercial fishery that uses alternative gear. This may encompass hand gathering without electric current, the use of salt or brine to stimulate clams leaving their burrows, or the use of suction dredges using either water or air. Mechanical dredging has been practiced in Portugal to target razor clams, but there is no history of this method for razor clams in Scotland, in comparison to its use in scallop fishing.

We consider the likely environmental effects of each reasonable alternative below.

6.6.2.1 Suction dredging

Suction dredging, also called hydraulic dredging, is the only fishing method that would be economically viable at the same scale as fishing with electric current. While not in use today, suction dredging using either water^[6] or air ^[7] has been historically practiced in fisheries targeting razor clams in Scotland. This mechanism injects water or air into the seabed, fluidising the sediment which is pumped aboard and sorted on deck. Methods using air pumps guided by divers can be highly selective, while hydraulic dredging with water is associated with high levels of bycatch^[8].

We do not consider this method likely to have materially different effects on food safety, worker safety or waste and circular economy objectives compared to fishing with electric current gear.

We do consider this method likely to have a higher risk of a negative effects on biodiversity, flora and fauna. This is because of the high level of bycatch in the case of hydraulic dredge which would likely increase the risk of this fishing method affecting prey availability to the extent of having an adverse impact on protected species in some areas. When assessing the potential impacts of razor clam activity with reference to the conservation and management advice of relevant Natura sites and MPAs, the advice relating to suction/hydraulic dredging is that the pressure associated with this activity be removed or avoided. Adopting this method of harvesting would make it significantly harder to integrate fisheries and conservation management priorities, plausibly resulting in closure of areas that could accommodate fishing with electric current without compromising site integrity.

We also consider this method likely to have a higher risk of a negative effect on sustainable harvesting. This is because this method can have a higher catch efficiency (approximately 90%^[9] compared to 82% per tow with electric current gear^[10]), increasing the risk of overexploitation, as razor clams are slow-growing species. Dredging is associated with shell margin breaks in clams that are subject to repeated dredge attempts, and undersized clams discarded from dredging take longer to reburrow compared to electrically stunned clams (on average approximately 14 minutes⁶ compared to 7 minutes^[11]). This is considered to have a higher risk of mortality from damage and predation, with potential effects on razor clam populations.

The Inshore Fishing (Prohibition of Fishing and Fishing Methods) (Scotland) Order 2004 bans the use of this method in sections of the inshore. With reference to areas that were included in the trial, if the consultation outcome was a commercial fishery that uses this method instead of electric current, no fishing could proceed in the Outer Hebrides, and there would also be limits on fishing in the Firth of Clyde and Solway Firth^[12]. Future work on inshore marine protection areas may expand areas with relevant gear restrictions.

6.6.2.2 Salt harvesting

Intertidal hand gathering is often achieved by depositing salt or brine solutions on exposed burrows, waiting for the clam to respond by being repulsed by the hypersaline conditions and exiting its burrow where it can be collected. In a similar way, there has historically been commercial subtidal gathering by divers using bottles of salt or brine which they could use to achieve the same result^[13].

We do not consider this method likely to have materially different effects on food safety or worker safety compared to fishing with electric current gear.

We do consider this method to increase the risk of waste and circular economy outcomes as there is greater potential for marine litter to enter the environment, dependent on the scale of uptake of such an activity. This would be in the form of salt containers and the salt itself.

While we have scoped effects on water out of this assessment, were there to be a consultation outcome that salt harvesting be an authorised mode of fishing for razor clams, this activity has the effect of discharging a substance into the environment that would require such impacts to be scoped in for further assessment. This would possibly require Controlled Activities Regulations authorisation, with associated resourcing implications for SEPA.

As this is not an activity that has been widely practiced in Scotland for some time, we do not understand the risk that this might pose to biodiversity, flora and fauna or razor clam populations as it would depend very much on scale of activity. We may expect localised hypersalinity associated with repeat harvest visits to increase the risk of negative effects on these objectives, but this is assessed at a low level of confidence.

6.7 Monitoring Framework

The three most pertinent environmental issues identified in this assessment report are ensuring activity does not compromise national and site-specific conservation objectives, ensuring overexploitation of this resource is avoided, and ensuring that what follows the trial does not erode progress made on sustainability, food safety and worker safety.

The current range of technical measures in use in the trial are intended to keep harvesting activity at a sustainable level. The consultation seeks views on whether these are appropriate, or if they can be changed and/or added to. Technical measure compliance is checked through our coastal offices as part of routine inshore fisheries compliance enforcement activity. Intelligence is shared among compliance, policy and scientific staff as necessary to ensure compliance with trial terms and conditions. Whatever future status arises from the consultation, the continued oversight of compliance with fisheries regulations by the Scottish Government Marine Directorate, as they apply to razor clams, will continue.

Remote electronic monitoring is the foundation for this as has been operated in the trial. Any outcome of the consultation resulting in further fishing activity will continue to be subject to this form of monitoring. The consultation seeks views on where this could be expanded, for example by including CCTV cameras or other sensors alongside the position and generator monitoring that is currently the basis of REM in the scientific trial.

Ensuring fishing activity does not compromise conservation priorities and site integrity will be managed with the advice of NatureScot.

In the consultation we seek views on the role stock assessment plays in managing any fishery that may arise. This would be managed in line with the wider programme of inshore fisheries management, which involves periodic assessment of stocks. Consultation on inshore fisheries management is planned for the near future.

Food safety would be monitored in any plan outcome that continues commercial fishing through the established channel for monitoring shellfish safety, led by Food Standards Scotland.

We consider outcomes that do not erode worker safety to be critically important, and any outcome either of a commercial or trial nature will ensure working conditions meet the necessary regulatory standards as determined by the Health and Safety Executive.

In summary we would anticipate the following indicators to be of use in monitoring authorised activity, should there be an outcome that fishing for razor clams continues under either a scientific trial or commercial fishery backdrop:

• Stock assessments, to ensure safe harvesting levels
• Landings per unit effort, to monitor trends between stock assessments
• Remote electronic monitoring data, to monitor vessel position and fishing activity to ensure fishing occurs in authorised areas
• Trends in protected species and habitat condition where fishing activity may have an influence, to monitor non-target species effects
• Shellfish classification results, to ensure food safety
• Health and safety incident monitoring, to ensure worker safety

This approach enables the Scottish Ministers to identify unforeseen impacts at an early stage, and where necessary undertake appropriate remedial action. How we monitor the fishery, in terms of frequency and granularity will be governed by fisheries management priorities within the Scottish Government and may involve phasing the introduction of identified improvements over some time.