Commercial fishery for razor clams using electric current gear - consultation: strategic environmental assessment report
An environment report following strategic environmental assessment of consultation outcomes for the consultation on establishing a commercial fishery for razor clams using electric current.
4. Environmental Baseline
As noted above, we organise baseline data by SMR but this does not mean that this would be the regional model used if a commercial fishery was established. The appropriate regional model will be determined using advice from the Marine Directorate fisheries scientists.
4.1 Solway SMR
Razor clam fishing in the trial has occurred in the sheltered bays of Wigtown Bay, Fleet Bay and Kirkcudbright Bay. Historically it has occurred in Luce Bay as well, and there is interest in reopening this area to fishing in future.
Sediments in the razor clam trial area in this SMR are predominantly muddy, with sandy sediments along the coast. Luce Bay is predominantly sandy with coarse sediments in deeper water. The outer firth itself is generally too deep for razor clam fishing with divers and is a mix of coarse and sandy sediments. If the consultation outcome were to result in a commercial fishery and there was demand to expand fishing for razor clams in this area beyond the area authorised in the trial, it is likely this would principally focus on Luce Bay where razor clam grounds are known to exist.
The five pressures affecting the SMR in are (1) removal of target species, (2) surface abrasion, (3) removal of non-target species, (4) sub-surface abrasion/penetration and (5) underwater noise. Several other pressures are outlined in Scotland’s Marine Assessment. There is no evidence of eutrophication as a consequence of nutrient enrichment in this SMR, but there is evidence of contaminant and microplastic pollution that are above background.
Bathing water classification has ranged from Sufficient to Excellent at 7 beaches between 2022 and 2025.
Shellfish food safety monitoring results of razor clam samples in Dumfries and Galloway local authority area found five instances of shellfish biotoxin levels above reporting limits. There were 153 occasions where areas received an A grade classification, twelve occasions where E. coli concentrations led to a B grade classification and two occasions with a C grade classification between 2018 and 2025.
This SMR is within Ayr Port District. Scallop and Nephrops are the main landed species and shellfish dominates landings in general ( Table 1). The Wigtown Bay trial area reported landings of between 9 and 62 tonnes of razor clams between 2018 and 2024.
(Table 1) Average landings by species into Ayr Port District, 2020-2024
Total demersal: 5.2 (tonnes)
Total pelagic: 1.4 (tonnes)
Total shellfish: 5,736 (tonnes)
Fishing for razor clams in the Solway Firth is generally in different areas to other fishing activity within the Solway SMR. In comparison to other authorised fishing activity, it is modest in scale (Table 2).
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 33 | No data | 5 |
| Nephrops and crustacean bottom trawls >12m | 47.3 | 58.7 | 21.7 |
| Dredges >12m | 599.5 | 302.6 | 88 |
| Pots and traps <12m | 21.3 | no data | 107 |
| Set nets <12m | no data* | no data | 8 |
| Bottom trawls <12m | no data* | no data | 8 |
| Diving/gathering <12m | no data* | no data | 2 |
| Dredges <12m | no data* | no data | 10 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels[1]. C-square resolution: 0.05x0.05°.
4.1.1 Solway SMR - MPA Network
There are several MPA network sites within this SMR, including the Solway Firth SPA and the Luce Bay and Sands SAC.
We categorise razor clam fishing activity as boat use associated with a commercial activity, and fishing with demersal mobile gear. These activities are associated with disturbance and removal of prey species and abrasion of pre-supporting habitat. A Habitats Regulations Appraisal (HRA) has been completed for the Solway Firth SPA, and fishing activity has been authorised there.
Management measures for fishing within the Solway Firth SPA have been amended following the HRA to reduce the risk of disturbance to seabirds, in line with the site’s conservation and management advice to reduce or limit pressures.
Because razor clam fishing has never been authorised in Luce Bay, no HRA has been undertaken in this SPA.
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Maerl beds
- Seagrass beds
- Native oysters
- Blue mussel beds
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs.
The fisheries assessment was based on the level of activity underway throughout the trial and may require to be revisited should the consultation outcomes result in a decision to authorise activity at a different scale in this region.
The likely impact on protected species and habitats in the event of a return to prohibition is set out later in this document.
4.2 Clyde SMR
Razor clam fishing occurs along the Ayrshire coast on a mix of sandy, muddy and coarse sediments. Mixed and sandy sediments predominate around the coast of the firth of Clyde, with mud in the central basin. Much of the Clyde is too deep for diving operations, so if the consultation outcome was the establishment of a commercial fishery or further scientific fishing, we would anticipate this to be at a similar scale to the current scientific trial in terms of the authorised footprint of a fishery. There may be interest in exploring small areas along the Kintyre coast and some of the islands in the firth where there are small areas of sandy sediment in shallow water.
This SMR overlaps with Campbeltown and Ayr port districts. Shellfish dominates landings in general (Table 3). The Clyde trial area reported landings of between 183 and 340 tonnes of razor clams between 2018 and 2024.
(Table 3) Average landings by species into Campbeltown and Ayr Port Districts, 2020-2024
Total demersal: 12.2 (tonnes)
Total pelagic: 2.4 (tonnes)
Total shellfish: 9,295.4 (tonnes)
Razor clam fishing activity is compared to other fishing activity in the Clyde SMR in Table 4. The level of activity is modest compared to other activity.
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 435.1 | No data | 21 |
| Nephrops and crustacean bottom trawls >12m | 7,176.44 | 4,743.7 | 165.7 |
| Dredges >12m | 270.26 | 132.01 | 92.7 |
| Pots and traps <12m | 47.5 | no data | 283 |
| Set nets <12m | no data* | no data | 7 |
| Bottom trawls <12m | 22.7 | no data | 193 |
| Diving/gathering <12m | no data* | no data | 77 |
| Dredges <12m | no data* | no data | 57 |
| Rods and lines <12m | no data* | no data | 18 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels. C-square resolution: 0.05x0.05°.
The five main pressures affecting the SMR are (1) removal of target species, (2) surface abrasion, (3) removal of non-target species, (4) underwater noise and (5) hydrocarbon and PAH contamination. Several other pressures are outlined in Scotland’s Marine Assessment. There is no evidence of eutrophication as a consequence of nutrient enrichment in this SMR, but there is evidence of contaminant and microplastic pollution that are above background.
Shellfish food safety monitoring results of razor clam samples in North Ayrshire and South Ayrshire local authority areas found three instances of shellfish biotoxin levels above reporting limits. There were 337 occasions where areas received an A grade classification, and 10 occasions where E. coli concentrations led to a B grade classification between 2018 and 2025.
4.2.1 Clyde SMR – MPA Network
There are two nature conservation MPAs in the Clyde SMR – the South Arran MPA and the Clyde Sea Sill MPA. Neither contain authorised sites for razor clams. Because no activity has been authorised in these areas, no nature conservation MPA assessment has been undertaken. Advice relating to boat use and mobile demersal gear is to reduce or limit pressures in the Clyde Sea Sill MPA, and extends to removing or avoiding pressures for some protected features within the South Arran MPA.
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Northern sea fan and sponge communities
- Maerl beds
- Maerl or coarse shell gravel with burrowing sea cucumbers
- Horse mussels
- Flame shell beds
- Fan mussels
- Seagrass beds
- Native oysters
- Blue mussel beds
Cod are also a PMF with importance in this SMR, however cod are not anticipated to be impacted by razor clam fishing – the footprint of the activity is small compared to other authorised forms of fishing and the gear moves so slowly when deployed that mobile fish species are generally free to evade it.
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs.
The fisheries assessment was based on the level of activity underway throughout the trial and may require to be revisited should the consultation outcome result in a decision to authorise activity at a different scale in this region.
4.3 Argyll SMR
Razor clam fishing in this SMR has occurred around Gigha, Colonsay, Coll and Tiree on a mix of sandy and coarse sediments. If the consultation outcome was a commercial fishery or further scientific fishing, we would anticipate this to be at a similar scale to the current scientific trial in terms of the authorised footprint of a fishery. This is because there are relatively few areas in this SMR where sandy sediment coincides with shallow water accessible by commercial divers.
This SMR overlaps with Campbeltown and Oban port districts. Nephrops and scallops are the main landed species and shellfish dominates landings in general (Table 5). The Gigha, Colonsay and Coll and Tiree trial areas reported landings of between 2 and 158 tonnes of razor clams between 2018 and 2024.
(Table 5) Average landings by species into Campbeltown and Oban Districts, 2020-2024
Total demersal: 55.6 (tonnes)
Total pelagic: 1.6 (tonnes)
Total shellfish: 5,714.6 (tonnes)
The five main pressures affecting the SMR are (1) removal of target species, (2) removal of non-target species, (3) surface abrasion, (4) synthetic compound contamination and (5) underwater noise. Several other pressures are outlined in Scotland’s Marine Assessment. There is no evidence of eutrophication as a consequence of nutrient enrichment in this SMR, but there is evidence of contaminant pollution that is above background.
Shellfish food safety monitoring results of razor clam samples in Argyll and Bute local authority area found twenty two instances of shellfish biotoxin levels above reporting limits. There were 525 occasions where areas received an A grade classification, and 41 occasions where E. coli concentrations led to a B grade classification between 2018 and 2025.
The footprint of razor clam fishing activity in trial areas within this SMR is shown in Table 6. The level of activity is generally modest in comparison to other authorised fishing activity.
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 47.9 | No data | 8 |
| Nephrops and crustacean bottom trawls >12m | 1,218.7 | 1,376.5 | 214 |
| Dredges >12m | 1,336.8 | 617.3 | 235 |
| Pots and traps <12m | 61.2 | no data | 646 |
| Dredges <12m | No data* | no data | 108 |
| Bottom trawls <12m | 8.4 | no data | 114 |
| Diving/gathering <12m | 9.3 | no data | 161 |
| Rods and Lines <12m | No data* | no data | 14 |
| Set Nets <12m | No data* | no data | 3 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels. C-square resolution: 0.05x0.05°.
4.3.1 Argyll SMR – MPA Network
There are several sites of importance to seabirds with SPA designations in this SPA that overlap with authorised sites for razor clam fishing:
- Sound of Gigha SPA
- North Colonsay and Western Cliffs SPA
- Coll and Tiree SPA
We categorise razor clam fishing activity as boat use associated with a commercial activity, and fishing with demersal mobile gear. These activities are associated with disturbance and removal of prey species and abrasion of pre-supporting habitat. Conservation and management advice for these SPAs and functionally linked habitat outside of them is to reduce or limit the these pressures. The risk of razor clam activity with reference to the conservation and management advice for these SPAs (in the context of a scientific trial) has been considered in a fisheries assessment.
There are also several MPAs and SACs in this SMR, though as no razor clam fishing has been authorised in these areas, they have not formed part of advice received by NatureScot before and during the trial.
SACs:
- South-East Islay Skerries SAC
- Inner Hebrides and the Minch SAC
- Firth of Lorn SAC
- Taynish and Knapdale Woods SAC
- Tayvallich Juniper and Coast SAC
- Moine Mhor SAC
- Loch Creran SAC
- Eileanan agus Sgeiran Lios mor SAC
- Treshnish Isles SAC
MPAs:
- Loch Sween MPA
- Loch Sunart to the Sound of Jura MPA
- Sea of the Hebrides MPA
- Loch Creran MPA
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Serpulid aggregations
- Northern sea fan and sponge communities
- Maerl beds
- Maerl or coarse shell gravel with burrowing sea cucumbers
- Horse mussel beds
- Flame shell beds
- Fan mussels
- Seagrass beds
- Native oysters
- Blue mussel beds
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs. As a precautionary measure and recognising that it is unlikely that fishing for razor clams could be accomplished in any event, a bay on Colonsay was closed to further fishing due to the presence of seagrass beds.
The fisheries assessment was based on the level of activity underway throughout the trial and may require to be revisited should the consultation outcomes result in a decision to authorise activity at a different scale in this region.
4.3.2 Special note on eider ducks
Peak counts of eider ducks in the Sound of Gigha have increased since the establishment of the trial. Fishing occurs from depths of 2-8 metres, which is within the range of depths at which eider can forage. Eider are predicted to occupy the area of the sound of Gigha to the north of Rhunahaorine Point (NatureScot, 2014), which overlaps with one razor ground in the trial area that was mainly fished in trial years 1-3 from 2018 to 2020.
The seasonal closure is during the end of the non-breeding season and into the breeding season but before the flightless moult period. Fishing effort has tended to be light in the breeding season and the July to September period of the flightless moult. Unlike in the Firth of Forth, eider are not reported to follow razor clam vessels, perhaps because fishing effort has fluctuated to a greater extent between years.
Eider are moderately sensitive to vessel disturbance (Furness, Wade, & Masden, 2013) however the small number of vessels and slow speed while fishing, considered in the wider context of fishing and non-fishing activity in the area and increasing counts in WeBS data indicates that razor clam fishing activity does not constitute a risk of significant disturbance.
Razor clam fishing activity is not considered to be a barrier to access to optimal habitat or to constitute a risk of significant disturbance. If fishing effort was to increase, this would need to be reappraised.
Eider feed on razor clams and other organisms that may inhabit razor clam fishing grounds. Over time, the spatial footprint of the fishery has decreased as has the reduction in effort and intensity (Blackadder, et al., 2024).
Eiders have a preference for small prey, with a maximum prey size of 80mm in length (Larsen & Guillemette, 2000). Razor clam harvesting is limited to a minimum conservation reference size of 100mm and a strong market preference for clams of 150mm or greater means that small numbers of small clams and negligible numbers of undersized clams are harvested across the trial (Blackadder, et al., 2024). Important subtidal mussel beds are present in West Loch Tarbert (NatureScot, 2025), but intertidal mussels on rocky substrates are poorly sampled for this location. As noted in site-specific information, benthic habitats that support eiders are likely to be extensive in the area and the relative lack of records for Gigha is likely a result of low sampling effort, rather than a genuine absence of prey species.
The sample lengths of landed razor clams for Gigha since the trial began until 2023, were between 100-220.50mm (Blackadder, 2024), therefore removals by trial participants are not considered to be removing items that would otherwise be prey for eiders.
Eider in Scotland roost during the night and therefore this behaviour does not interact with day-time razor clam fishing activity or boat movements.
Scotland’s Marine Assessment indicated a stable trend for nutrients and chlorophyll in the Argyll Scottish Marine Region (Scottish Government, 2020). Razor clam fishing activity may cause localised increases in turbidity at the seabed during fishing operations, but this is not considered likely to contribute to a deterioration in water quality locally or at the water body scale.
Sandy and muddy sediments that support razor clams are evidently present in the area, but the extent to which these extend beyond the fished area is currently not known (EMODnet, 2023). Generally, these areas are restricted to the portions of the trial areas that are fished (Blackadder, et al., 2024). The small number of vessels active in the area and fluctuating effort means razor clam fishing is not considered to affect benthic habitats to the extent that it adversely affects prey availability.
4.4 Outer Hebrides SMR
Razor clam fishing has occurred in Broad Bay and Benbecula on sandy and mixed sediments. Seabed type is diverse in the Hebrides ranging from sandy in some sea lochs to rocky and mixed in other areas. Broad Bay is one significant area of sandy sediment, otherwise razor clams tend to inhabit localised pockets of suitable sediment within areas of mixed substrates. Therefore if the consultation outcome was a commercial fishery or further scientific fishing, we would anticipate this to be at a similar scale to the current scientific trial in terms of the authorised footprint of a fishery, though we recognise that knowledge of the whereabouts of razor clam grounds in this area is limited and this would need to be kept under review. There is interest in accessing known grounds adjacent to the Eriskay causeway due to high densities[2], however as this is located in the Sound of Barra SAC, no fishing has been permitted to date as no HRA has been conducted.
This SMR overlaps with Stornoway port district. Nephrops is the main landed species and shellfish dominates landings in general (Table 7). The Broad Bay trial area reported landings of between 9 and 28 tonnes of razor clams between 2018 and 2024.
(Table 7) Average landings by species into Stornoway District, 2020-2024
Total demersal: 86 (tonnes)
Total pelagic: 5.4 (tonnes)
Total shellfish: 2,896.2 (tonnes)
Razor clam fishing activity is compared to other fishing activity in the SMR in Table 6. The footprint of razor clam trial fishing is modest in comparison to other methods.
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 32.7 | No data | 3 |
| Nephrops and crustacean bottom trawls >12m | 2,052.1 | 1,854.2 | 211 |
| Dredges >12m | 455.4 | 258.7 | 119 |
| Pots and traps <12m | 37.3 | no data | 791 |
| Dredges <12m | No data* | no data | 23 |
| Bottom trawls <12m | No data* | no data | 131 |
| Diving/gathering <12m | No data* | no data | 80 |
| Rods and Lines <12m | No data* | no data | 15 |
| Set Nets <12m | No data* | no data | 8 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels. C-square resolution: 0.05x0.05°.
The five main pressures affecting the SMR are (1) removal of target species, (2) removal of non-target species, (3) surface abrasion, (4) sub-surface abrasion / penetration and (5) underwater noise. Several other pressures are outlined in Scotland’s Marine Assessment. There is no evidence of eutrophication as a consequence of nutrient enrichment in this SMR, but there is evidence of contaminant pollution that is above background. Microplastic and marine litter data are sparse but where they exist indicate low levels compared to other SMRs.
Shellfish food safety monitoring results of razor clam samples in Comhairle nan Eilean Siar: Lewis and Harris local authority area found twenty-four instances of shellfish biotoxin levels above reporting limits. There were 84 occasions where areas received an A grade classification, one occasion where E. coli concentrations led to a B grade classification and one occasion leading to a C grade classification between 2018 and 2025.
4.4.1 Outer Hebrides SMR – MPA Network
There are several MPAs, SPAs and SACs in this SMR. The impact of razor clam fishing (in the context of a scientific trial) on relevant sites was assessed in a fisheries assessment, following advice from NatureScot. This focused on the West Coast of the Outer Hebrides SPA and the North-East Lewis MPA. The conservation and management advice relating to boat use and fishing with demersal gear is to reduce or limit pressures for the relevant protected features. Following the assessment, no change to trial management was identified as necessary in relation to the conservation objectives of these sites. As noted above, interest exists in fishing within the Sound of Barra SAC, however as no razor clam fishing activity has been authorised in this area, this has not progressed and no HRA has been completed in this area.
SPAs:
- Mingulay and Berneray SPA
- West Coast of the Outer Hebrides SPA
- Shiant Isles SPA
- Flannan Isles SPA
- Sea off St. Kilda SPA
- St. Kilda SPA
SACs:
- East Mingulay SAC
- Sound of Barra SAC
- Loch nam Madadh SAC
- Monach Islands SAC
- Inner Hebrides and the Minch SAC
- Loch Roag Lagoons SAC
- St. Kilda SAC
MPAs:
- Sea of the Hebrides MPA
- North-east Lewis MPA
- Shiant East Bank MPA
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Northern sea fan and sponge communities
- Maerl beds
- Maerl or coarse shell gravel with burrowing sea cucumbers
- Horse mussel beds
- Fan mussels
- Cold water coral reefs
- Seagrass beds
- Native oysters
- Blue mussel beds
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs.
The fisheries assessment was based on the level of activity underway throughout the trial and may require to be revisited should the consultation outcomes result in a decision to authorise activity at a different scale in this region.
4.5 West Highlands SMR
Razor clam fishing has occurred along the Arisaig coast of the Sound of Sleat, mainly on sandy sediments. Seabed types are diverse in this region, with sandy seabeds along coastlines and muddy, coarse, mixed and rocky seabeds in open sea areas and some sea lochs. If the consultation outcome was a commercial fishery or further scientific fishing, we would anticipate this to be at a similar scale to the current scientific trial in terms of the authorised footprint of a fishery. This is because historically this area has not been consistently fished. There is anecdotal evidence of high densities of razor clams in some sea lochs[3], however these did not form part of the trial.
This SMR is overlaps with Mallaig, Portree and Ullapool port districts. Only Mallaig and Portree are close to where razor clam fishing has been underway in the trial, so the focus is on these districts. Shellfish dominates landings in general, though there are landings of demersal and pelagic fish in modest quantities (Table 9). The Sound of Sleat trial area reported landings of between 2 and 74 tonnes of razor clams between 2018 and 2024.
(Table 9) Average landings by species into Mallaig and Portree Districts, 2020-2024
Total demersal: 221.2 (tonnes)
Total pelagic: 302.6 (tonnes)
Total shellfish: 5,194.2 (tonnes)
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 39.6 | No data | 5 |
| Nephrops and crustacean bottom trawls >12m | 3,586.4 | 3,574.1 | 381 |
| Dredges >12m | 1,095.9 | 532.9 | 230 |
| Pots and traps <12m | 40.5 | no data | 767 |
| Dredges <12m | No data* | no data | 20 |
| Bottom trawls <12m | 10.6 | no data | 350 |
| Diving/gathering <12m | 8.9 | no data | 324 |
| Rods and Lines <12m | No data* | no data | 26 |
| Set Nets <12m | No data* | no data | 2 |
| Other <12m | No data* | no data | 2 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels. C-square resolution: 0.05x0.05°.
The five main pressures affecting the SMR are (1) removal of target species, (2) removal of non-target species, (3) surface abrasion, (4) synthetic compound contamination and (5) sub-surface abrasion / penetration. Several other pressures are outlined in Scotland’s Marine Assessment. There is no evidence of eutrophication as a consequence of nutrient enrichment in this SMR, but there is evidence of contaminant pollution that is above background. Microplastic and marine litter data indicate low levels and a stable trend.
Shellfish food safety monitoring results of razor clam samples in Highland: Skye and Lochalsh local authority area found six instances of shellfish biotoxin levels above reporting limits. There were 42 occasions where areas received an A grade classification, and one occasion where E. coli concentrations led to a B grade classification between 2018 and 2025.
4.5.1 West Highlands SMR - MPA Network
There are several MPAs, SPAs and SACs in this SMR. The impact of razor clam fishing on relevant sites (in the context of a scientific trial) was assessed in a fisheries assessment, following advice from NatureScot. As no activity with connectivity to these sites has been authorised, no appraisals were determined to be necessary for any site in this SMR, however the potential impact on the national status of PMFs were assessed.
SPAs:
- Canna and Sanday SPA
- Rum SPA
SACs:
- Lochs Duich, Long and Alsh Reefs SAC
- Inner Hebrides and the Minches SAC
- Sound of Arisaig (Loch Ailort to Loch Ceann Traigh) SAC
- Sunart SAC
MPAs:
- Sea of the Hebrides MPA
- Small Isles MPA
- Lochs Duich, Long and Alsh MPA
- Red Rocks and Longay MPA
- Wester Ross MPA
- Shiant East Bank MPA
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Serpulid aggregations
- Northern sea fan and sponge communities
- Maerl beds
- Maerl or coarse shell gravel with burrowing sea cucumbers
- Horse mussel beds
- Flame shell beds
- Fan mussels
- Seagrass beds
- Native oysters
- Blue mussels
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs.
The fisheries assessment was based on the level of activity underway throughout the trial and would likely require to be revisited should a commercial fishery be the outcome of the consultation.
4.6 Forth and Tay SMR
Razor clam fishing has occurred on sandy sediments, which occur on the north and south coasts from the estuary to east Fife and East Lothian. The main channel is too deep for diving and is composed mainly of mud. Coarse and rocky sediments exist along the North Sea coasts exiting the Firth of Forth. Sandy sediments predominate in the North Sea portion of this SMR, however these are also too deep for diving. If the consultation outcome was the establishment of a commercial fishery or further scientific fishing, we would anticipate this to potentially be at a moderately larger scale compared to the current scientific trial in terms of the authorised footprint of a fishery. There is anecdotal evidence of razor clam grounds in pockets beyond the trial boundary along the east fife coast, and in St. Andrews Bay. If there was demand to expand access in this SMR, we anticipate it would be in these areas.
This SMR overlaps with Anstruther and Eyemouth port districts. Shellfish dominates landings in general (Table 11). The Forth trial area reported landings of between 95 and 184 tonnes of razor clams between 2018 and 2024.
(Table 11) Average landings by species into Anstruther and Eyemouth Districts, 2020-2024
Total demersal: 26.6 (tonnes)
Total pelagic: 46.6 (tonnes)
Total shellfish: 3,194.4 (tonnes)
The five main pressures affecting the SMR are (1) removal of target species, (2) removal of non-target species, (3) physical change, (4) surface / sub-surface abrasion / penetration, and (5)underwater noise. Other pressures identified are Introduction of non-indigenous species and Litter. Nutrient inputs to the Forth and Tay SMR are some of the highest of any SMR although there is no evidence of eutrophication in this SMR. Contaminant concentrations are generally above background. Litter and microplastics are present with a mixed picture of some items increasing whilst others are decreasing. Significant programmes of offshore renewable energy infrastructure construction are underway in this SMR.
The footprint of fishing activity in the SMR is summarised in Table 12.
| Activity | Annual Average Fishing Effort (Days) | Swept seabed area (km2) | Footprint (c-squares) |
|---|---|---|---|
| Razor clam trial | 172.8 | no data | 10 |
| Nephrops and crustacean bottom trawls >12m | 2,960.0 | 2,285.8 | 146 |
| Dredges >12m | 242.4 | 165.2 | 95 |
| Pots and traps <12m | 89.8 | no data | 305 |
| Rods and Lines <12m | 18 | no data | 87 |
| Bottom trawls <12m | 19.6 | no data | 190 |
| Dredges <12m | 46.5 | no data | 32 |
| Diving/gathering <12m | no data* | no data | 5 |
| Set nets | no data* | no data | 2 |
Note: Under 12m data is sourced from Scottish Sea Fisheries Statistics spatial data. Over 12m data is sourced from ICES. ICES data are reported in hours and were converted to days by dividing by 12. * redacted due to number of vessels. C-square resolution: 0.05x0.05°.
Shellfish food safety monitoring results of razor clam samples in East Lothian and Fife local authority areas found 40 instances of shellfish biotoxin levels above reporting limits. There were 163 occasions where areas received an A grade classification, 46 one occasions where E. coli concentrations led to a B grade classification and three occasions leading to a C grade classification between 2018 and 2025.
4.6.1 Forth and Tay SMR - MPA Network
There are several MPAs, SPAs and SACs in this SMR. The impact of razor clam fishing on relevant sites (in the context of a scientific trial) was assessed in a fisheries assessment, following advice from NatureScot. Some seabird species were identified a being at potential risk of disturbance by fishing activity and changes to management restricting access to some areas was implemented as a result.
SPAs:
- Outer Firth of Forth and St Andrews Bay Complex SPA
- St Abb's Head to Fast Castle SPA
- Forth Islands SPA
- Firth of Forth SPA
- Firth of Tay and Eden Estuary SPA
SACs:
- Firth of Tay and Eden Estuary SAC
- Isle of May SAC
- Berwickshire and North Northumberland Coast SAC
MPAs:
- Firth of Forth Banks Complex MPA
The following priority marine features, identified as vulnerable to bottom-contact fishing gear, are present in this SMR:
- Maerl or coarse shell gravel with burrowing sea cucumbers
- Horse mussel beds
- Seagrass beds
- Blue mussel beds
The impact of trial vessel fishing activity was assessed in relation to the national status of PMFs, with the conclusion that activity did not significantly adversely affect the status of any of these PMFs.
The fisheries assessment was based on the level of activity underway throughout the trial and may require to be revisited should the consultation outcomes result in a decision to authorise activity at a different scale in this region.
4.6.2 Special note on eider ducks
The small number of vessels operating out of established fishing ports against the context of fishing and wider non-razor clam vessel activity in the SPA and connected areas at large, and the slow speed while engaged in fishing is not considered to represent a significant risk to the seabirds through either collisions or effects of evading vessel movements.
There is evidence that eider ducks have to some extent become habituated to the presence of razor clam vessels. Groups of up to 100 ducks have been observed following razor clam vessels and observed on video of diving operations taking stunned clams (Fox, Report on razor clam surveys in Largo bay (Firth of forth)., 2021). There have been no reports of mortality or injury attributable to fishing operations during the trial in this area.
WeBS alert data for eider at the overlapping Firth of Forth SPA up to winter of 2021/22 show a log term declining trend. The BTO consider the decline of eiders in this area to have been exacerbated as a result of site-specific pressures (Caulfield, Feather, Smith, Frost, & Woodward, 2025). WeBS peak counts for the Forth Estuary site on Inchcolm Island also show a decline in eiders when comparing the period prior to the razor clam trial to after the commencement of the trial, though many surveys are flagged incomplete and excluded from statistics by BTO.
Razor clam fishing activity involves travel from established ports to razor clam trial grounds for fishing operations. This does not constitute a large-scale physical barrier.
A seasonal closure is in place in the trial from late April to Late May during which no fishing activity will take place, this overlaps with the end of the non-breeding season between September and April. The flightless moult period is between July and September. 31.2% of fishing hours have occurred during the flightless moult months, with effort declining from August.
Razor clam fishing activity occurs in depths that eiders are capable of foraging in. As noted, eider in this trial area are reported to follow razor clam vessels while foraging and are therefore not considered to be disturbed by vessel activity.
Eider feed on razor clams and other organisms that may inhabit razor clam fishing grounds. The stock assessment for the Forth trial area found the level of fishing mortality to be below the estimated maximum sustainable yield level, therefore fishing activity within the SPA is not reducing the biomass of razor clams (Blackadder, et al., 2024). Eiders have a preference for small prey, with a maximum prey size of 80mm in length (Larsen & Guillemette, 2000). Razor clam harvesting is limited to a minimum conservation reference size of 100mm and a strong market preference for clams of 150mm or greater means that small numbers of small clams and negligible numbers of undersized clams are harvested across the trial (Blackadder, et al., 2024).
The population of clams in Largo bay is heavily weighted towards large clams (Blackadder, et al., 2024), therefore there is limited overlap in harvesting between eider foraging for razors and targeted removal by razor clam vessels.
As noted, eiders follow razor clam vessel and have been observed diving close to divers and taking small clams. This may constitute an additional prey source that ducks have become habituated to exploiting as the energetic cost of taking shocked clams versus digging for them is likely to be lower. Consequently, any change in razor clam fishing may impact the variety and abundance of food resources for eiders.
Largo Bay is in shallower water than Gullane Bay and therefore there may be greater following behaviour in the former than the latter. The stronger tidal currents in Gullane Bay may make this habitat less suitable for eider than Largo Bay (Scanlon & Strickland, 2024).
Eider have a preference for small sized mussels. Razor clam fishing is not expected to affect blue mussel habitat. These are mainly found on rocky or cobbly substrate that is separated from razor clam activity (Scottish Government, 2018) subtidal beds on muddy or sandy sediment are not found within the areas of razor clam fishing activity (NatureScot, 2025). Intertidal mussels are widely distributed within the SPA, as are other prey fauna such as common cockles and shore crabs.
Evidence gathered before and during the trial points to only short term and recoverable effects of electric current on crabs (Blackman, Fox, & Albalat, 2024) and bivalves (Murray, Copland, Boulcott, Roberston, & Bailey, 2014). Combined with the minimal physical impact on the seabed and highly localised footprint of the trial fishery, the activity is not considered to be capable of damaging benthic habitats in the SPA to the extent that it adversely affects prey availability for eiders.
Scotland’s Marine Assessment indicates while nutrient inputs and chlorophyll concentrations are high in the Forth and Tay Scottish Marine Region which overlaps with the SPA, this did not amount to eutrophication (Scottish Government, 2020). Razor clam fishing activity may cause localised increases in turbidity at the seabed during fishing operations, but this is not considered likely to contribute to a deterioration in water quality locally or at the water body scale.