Scottish Offshore Marine Protected Areas (MPAs) - fisheries management measures: fisheries assessment – Geikie Slide and Hebridean Slope NCMPA

2. Part A assessment – fisheries screening

2.1 Fisheries screening overview

Part A of this assessment considers whether the fishing activity would be capable of impacting the protected features of an MPA or any ecological or geomorphological process on which the conservation of any protected feature is dependent. This section looks at the pressures exerted by the fishing activity occurring in the site (within the assessment period) in relation to the sensitivities of the protected features. Activities potentially capable of impacting the protected features were identified where there was both a medium-high risk of a pressure arising from the fishing activity and if any of the features were considered sensitive to that pressure. These pressure-features interactions were then taken forward to the fisheries assessment stage (Part B) to determine whether the fishing activity in question would or might hinder the achievement of the conservation objectives.

For each activity assessed in Part A, there were two possible outcomes for each identified pressure-feature interaction:

1. The pressure-feature interactions were not included for Part B:

• If the features is not exposed to the pressure, and is not likely to be in the future; or
• If the effect/impact of the pressure is non-existent or insignificant.

2. The pressure-feature interactions were included for assessment in Part B:

• If the feature is exposed to the pressure, or is it likely to be in the future; and
• If the pressure is capable of impacting the feature; or
• If it is not possible to determine whether pressure is capable of impacting the feature.

Part B of the assessment considers the potential for activities to impact the feature by assessing the impact of fishing gears identified in Part A. This involves determining the potential level of interaction between the feature and the fishing activity, assessing the potential impact on the feature, and subsequently if fishing activities would or might hinder the achievement of the conservation objectives for the site.

Consideration of exposure to and the effect of a pressure on a protected feature of the MPA includes the consideration of exposure to and the effect of that pressure on any ecological or geomorphological process on which the conservation of the protected feature is wholly or in part dependant.

The JNCC Conservation Advice package and Fisheries Management Options Paper has been used to inform this assessment. This is the most recent assessment package and options paper available.

Where appropriate, this advice has been supplemented by information on pressures associated with fishing activity from the JNCC Marine Pressures-Activities Database (PAD) v1.5 2022 and the Feature Activity Sensitivity Tool (FeAST).

2.2 Activities taking place within Geikie Slide and Hebridean Slope NCMPA

To screen out fishing activities that were not taking place within the site or likely to take part in the future, Vessel Monitoring System (VMS) data within Geikie Slide and Hebridean Slope NCMPA from 2015 to 2019 were analysed to identify the gear types being used in the site and the aggregated gear method (Table 1). The fishing gears screened out at this stage were not taken forward to Part B of the assessment.

Table 1. Gear types recorded from the site based on VMS-linked point logbook data (UK vessels only) from 2015 to 2019.

Gear type: Towed

Specific Gear Type: Bottom otter trawl

Gear code: OTB

Aggregated gear method: Demersal trawls

Gear type: Towed

Specific Gear Type: Multi-rig trawls

Gear code: OTT

Aggregated gear method: Demersal trawls

Gear type: Towed

Specific Gear Type: Pair trawl

Gear code:PTB

Aggregated gear method: Demersal trawls

Gear type: Towed

Specific Gear Type: Bottom trawls (not specified)

Gear code: TB

Aggregated gear method: Demersal trawls

Gear type: Lines

Specific Gear Type: Longlines (not specified)

Gear code: LL

Aggregated gear method: Anchored nets/lines

Gear type: Lines

Specific Gear Type: Set longlines

Gear code: LLS

Aggregated gear method: Anchored nets/lines

Gear type: Towed (pelagic)

Specific Gear Type: Mid-water (pair)

Gear code: PTM

Aggregated gear method: Pelagic fishing

Gear type: Towed (pelagic)

Specific Gear Type: Mid-water trawl (single)

Gear code: OTM

Aggregated gear method: Pelagic fishing

Although pelagic trawling occurs within the site, JNCC have provided evidence within the Fisheries Options paper to consider this pelagic trawling and purse seining are not capable of impacting the protected features as this fishing activity does not have contact with the seabed.

2.3 Potential pressures exerted by site fishing activity

According to the JNCC Geikie Slide and Hebridean Slope NCMPA Management Options Paper (2014), the fishing activities considered capable of impacting the burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features are beam trawling, line fishing, otter trawling and set netting.

The potential pressures that could be exerted by fishing activities considered capable of impacting the burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features were determined using information on activity-pressure relationships in the JNCC Marine Pressures-Activities Database (PAD) v1.5 2022. The potential pressures that could be exerted by demersal trawls and anchored nets/lines are summarised in Table 2.

The aggregated gear type of ‘anchored nets/lines’ spans two categories in the PAD: set (fixed) net fishing and line fishing. Subsequently, potential pressures for this aggregated gear type were listed under the two PAD categories (Table 2). The risk profiling of pressures was the same for set (fixed) net fishing and line fishing within PAD, confirming that these categories could be considered together under the aggregated gear type of ‘anchored nets/lines’ in later sections of the assessment.

Table 2. Potential pressures exerted by demersal trawls and anchored net/lines taken from the JNCC Marine Pressures-Activities Database (PAD) v1.5 2022. The PAD risk profiling of pressures score represents the general risk the pressures pose to the environment under normal conditions. Pressures are categorised as posing a medium/high risk (dark blue) or low risk (light blue). Pressures that are not exerted by the fishing activity are classed as not relevant (white).

PAD Pressure: Transition elements and organo-metal (e.g. TBT) contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Hydrocarbon and PAH contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Synthetic compound contamination (incl. pesticides, antifoulants, pharmaceuticals). Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Deoxygenation

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Nutrient enrichment

Demersal trawls: Low

Anchored nets / lines: line fishing: Not relevant

PAD Pressure: Organic enrichment

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Physical change (to another seabed type)

Demersal trawls: Low

Anchored nets / lines: line fishing: Not relevant

PAD Pressure: Physical change (to another sediment type)

Demersal trawls: Low

Anchored nets / lines: line fishing: Not relevant

PAD Pressure: Abrasion/disturbance of the substrate on the surface of the seabed

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Medium-high

PAD Pressure: Penetration and/or disturbance of the substrate below the surface of the seabed, including abrasion

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Low

PAD Pressure: Changes in suspended solids (water clarity)

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Not relevant

PAD Pressure: Smothering and siltation rate changes (Light)

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Not relevant

PAD Pressure: Litter

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Underwater noise changes

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Introduction of light

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Barrier to species movement

Demersal trawls: Not relevant

Anchored nets / lines: line fishing: Low

PAD Pressure: Collision BELOW water with static or moving objects not naturally found in the marine environment (e.g. boats, machinery and structures)

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Visual disturbance

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Introduction or spread of invasive non-indigenous species (INIS)

Demersal trawls: Low

Anchored nets / lines: line fishing: Low

PAD Pressure: Removal of non-target species

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Medium-high

PAD Pressure: Removal of target species

Demersal trawls: Medium-high

Anchored nets / lines: line fishing: Medium-high

2.4 Significance of effects/impacts to protected features

In the absence of a JNCC Advice on Operations advice package for this site, the Feature Activity Sensitivity Tool (FeAST) was used to determine the potential sensitivity of the Burrowed mud, Offshore deep-sea mud and Offshore subtidal sands and gravels features (Table 3) to the pressures exerted by the relevant fishing activities (Table 2).

Table 3 identifies the pressures from particular gears that could be capable of impacting each feature. Where a pressure from a particular gear is identified as being capable of impacting a feature, justification is provided. To ensure the effects of fishing activities in-combination with other activities (including other fishing activities) are fully assessed, the pressures from fishing activities which were not identified as being capable of impacting a feature, but which do interact with the feature are considered in the in-combination aspect of the assessment (Part C).

Potential Pressures: Deoxygenation

Burrowed mud (including sea-pens): Low

Offshore deep-sea muds: Not exposed

Offshore sands and gravels: Not exposed

Potential Pressures: Hydrocarbon and PAH contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Burrowed mud (including sea-pens): Sensitive

Offshore deep-sea muds: Sensitive

Offshore sands and gravels: Sensitive

Potential Pressures: Nutrient enrichment

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not sensitive

Offshore sands and gravels: Not sensitive

Potential Pressures: Organic enrichment

Burrowed mud (including sea-pens): Medium

Offshore deep-sea muds: High

Offshore sands and gravels: High

Potential Pressures: Synthetic compound contamination (incl. pesticides, antifoulants, pharmaceuticals). Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Burrowed mud (including sea-pens): Sensitive

Offshore deep-sea muds: Sensitive

Offshore sands and gravels: Sensitive

Potential Pressures: Transition elements and organo-metal (e.g. TBT) contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Burrowed mud (including sea-pens): Sensitive

Offshore deep-sea muds: Sensitive

Offshore sands and gravels: Sensitive

Potential Pressures: Abrasion/disturbance of the substrate on the surface of the seabed

Burrowed mud (including sea-pens): Medium

Offshore deep-sea muds: High*

Offshore sands and gravels: High

Potential Pressures: Changes in suspended solids (water clarity)

Burrowed mud (including sea-pens): Low

Offshore deep-sea muds: Not exposed

Offshore sands and gravels: Not exposed

Potential Pressures: Collision BELOW water with static or moving objects not naturally found in the marine environment (e.g., boats, machinery, and structures)

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not assessed

Potential Pressures: Introduction of light

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not assessed

Potential Pressures: Litter

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not assessed

Potential Pressures: Penetration and/or disturbance of the substrate below the surface of the seabed, including abrasion

Burrowed mud (including sea-pens): Medium

Offshore deep-sea muds: High

Offshore sands and gravels: High

Potential Pressures: Physical change (to another seabed type)

Burrowed mud (including sea-pens): High

Offshore deep-sea muds: High

Offshore sands and gravels: High

Potential Pressures: Physical change (to another sediment type)

Burrowed mud (including sea-pens): High

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not assessed

Potential Pressures: Smothering and siltation rate changes (Light)

Burrowed mud (including sea-pens): Low

Offshore deep-sea muds: High

Offshore sands and gravels: High*

Potential Pressures: Underwater noise changes

Burrowed mud (including sea-pens): Not Sensitive

Offshore deep-sea muds: Not sensitive

Offshore sands and gravels: Not sensitive

Potential Pressures: Visual disturbance

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not assessed

Potential Pressures: Introduction or spread of invasive non-indigenous species (INIS)

Burrowed mud (including sea-pens): No assessment

Offshore deep-sea muds: Not assessed

Offshore sands and gravels: Not sensitive

Potential Pressures: Removal of non-target species

Burrowed mud (including sea-pens): Medium*

Offshore deep-sea muds: High

Offshore sands and gravels: High

Potential Pressures: Removal of target species

Burrowed mud (including sea-pens): Medium

Offshore deep-sea muds: Not exposed

Offshore sands and gravels: Not exposed

*An asterisk is used to denote an underlaying range of sensitivities for habitat features (e.g. due to the feature including species with a range of different sensitivities to a pressure). High* denotes that the highest sensitivity score for the features is high; medium* denotes that the highest sensitivity score for the feature is medium. Unknown is used where there is no information in FeAST about the sensitivity of this habitat to the pressure listed.

Considering both the information on the pressure activity association (Table 2) and the sensitivity of the subtidal sands and gravels feature (Table 3), pressures that have the potential to impact the feature are summarised in Table 4.

Pressures that are not relevant to demersal trawls and anchored nets/lines (pressures that are not exerted by that fishing activity: ‘not relevant to the activity’ in Table 2) do not need to be considered further in the assessment. According to the PAD methods document (Robson et al., 2018), pressures with low risk profiles (i.e. ‘low’ risk profile for the activity: Tables 2 and 4) generally do not occur at a level of concern and should not require consideration as part of an assessment, unless there are evidence-based case or site-specific factors that increase the risk, or there is uncertainty on the level of pressure on a receptor. Pressures with ‘medium-high’ risk profiles are commonly induced by the activity at a level that needs to be considered further as part of an assessment.

Pressures with a medium-high risk profile in PAD and to which FeAST assessed the feature as being Sensitive, Medium Sensitivity or High Sensitivity have the potential to impact the feature.

Of all the pressures considered, six have medium-high risk profiles (PAD) and have medium-high sensitivity (FeAST): abrasion/disturbance of the substrate on the surface of the seabed; penetration and/or disturbance of the substrate below the surface of the seabed, including abrasion; changes in suspended solids (water clarity); smothering and siltation rate changes (light); removal of target species; and removal of non-target species (Table 4). These six pressures are subsequently considered to have the potential to impact the burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features. All six of these pressures are exerted by demersal trawls. Of these pressures exerted by anchored nets/lines only three pressures; abrasion/disturbance of the substrate on the surface of the seabed; removal of target species and removal of non-target species (Table 4) are considered to have the potential to impact the burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features.

To ensure the effects of fishing activities in-combination with other activities (including other fishing activities) are fully assessed, the pressures from fishing activities which were not identified as capable of impacting the feature but which do interact with the features are considered in the in-combination aspect of the assessment (Part C).

Table 4. Summary of pressures that have the potential to impact the feature, based on pressure-activity associations (Table 2) and sensitivity of the subtidal sands and gravels feature (Table 3). Pressures with the potential to impact the feature are in dark blue.

Potential Pressure: Transition elements and organo-metal (e.g. TBT) contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although some features may be sensitive, there is a low risk profile for the activities.

Potential Pressure: Hydrocarbon and PAH contamination. Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although some features may be sensitive, there is a low risk profile for the activities.

Potential Pressure: Synthetic compound contamination (incl. pesticides, antifoulants, pharmaceuticals). Includes those priority substances listed in Annex II of Directive 2008/105/EC.

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although some features may be sensitive, there is a low risk profile for the activities.

Potential Pressure: Deoxygenation

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – the pressure has a low risk profile for the activities, and Burrowed mud has low sensitivity to this pressure (the other protected features are either not exposed or sensitivity is not assessed).

Potential Pressure: Nutrient enrichment

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – low risk profile for demersal trawls (and is not relevant for anchored nets/lines) and the protected features are either not assessed or not sensitive.

Potential Pressure: Organic enrichment

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although offshore deep-sea muds and offshore sands and gravels have high sensitivity and burrowed mud has medium sensitivity to this pressure, there is a low risk profile for these activities

Potential Pressure: Physical change (to another seabed type)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although the habitat features have high sensitivity to this pressure, the pressure has a low risk profile for demersal trawls and is not relevant for anchored nets/lines

Potential Pressure: Physical change (to another sediment type)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – although burrowed mud has high sensitivity to this pressure (other protected features are not assessed), the pressure has a low risk profile for the demersal trawls and is not relevant for anchored nets/lines

Potential Pressure: Abrasion/disturbance of the substrate on the surface of the seabed

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – the pressure has a medium-high risk profile for demersal trawls and anchored nets/lines AND the habitat features have either high sensitivity (offshore deep-sea muds and offshore sands and gravels) or medium sensitivity (burrowed mud) to this pressure.

Potential Pressure: Penetration and/or disturbance of the substrate below the surface of the seabed, including abrasion

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – the pressure has a medium-high risk profile for demersal trawls, and a low risk profile for anchored nets/lines AND the habitat features have either high sensitivity (offshore deep-sea muds, and offshore sands and gravels) or medium sensitivity (burrowed mud) to this pressure

Potential Pressure: Changes in suspended solids (water clarity)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – burrowed mud has low sensitivity to this pressure AND the pressure has a medium-high risk profile for demersal trawls, although itis not relevant for anchored nets/lines. Offshore deep-sea muds and offshore sands and gravels are not exposed.

Potential Pressure: Smothering and siltation rate changes (Light)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – the pressure has a medium-high risk profile for demersal trawls (although it is not relevant for anchored nets/lines), AND the protected habitat features have either high (offshore deep-sea muds, and offshore sands and gravels) or low sensitivity (burrowed mud).

Potential Pressure: Litter

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – low risk profile for activities (protected feature sensitivity is not assessed)

Potential Pressure: Underwater noise changes

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – low risk profile for activities (burrowed mud, offshore deep-sea muds, and offshore sands and gravels are not sensitive).

Potential Pressure: Introduction of light

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – sensitivity of all protected features is not assessed but there is a low risk profile for activities

Potential Pressure: Collision BELOW water with static or moving objects not naturally found in the marine environment (e.g. boats, machinery and structures)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – sensitivity of all protected features is not assessed but there is a low risk profile for activities

Potential Pressure: Visual disturbance

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – sensitivity of all protected features is not assessed but there is a low risk profile for activities

Potential Pressure: Introduction or spread of invasive non-indigenous species (INIS)

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: No – sensitivity of protected features is not assessed (except offshore sands and gravels which is not sensitive), but there is a low risk profile for activities.

Potential Pressure: Removal of non-target species

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – the pressure has a medium-high risk profile for these activities AND offshore deep-sea muds and offshore sands and gravels have high sensitivity, burrowed mud has medium sensitivity.

Potential Pressure: Removal of target species

Fishing activity – Demersal trawls and Anchored nets/lines: line fishing: Yes – the pressure has a medium-high risk profile for these activities AND burrowed mud has medium sensitivity (all other protected features are not exposed).

2.5 Part A Conclusion

Considering the information on pressures and sensitivity above, demersal mobile fishing (trawls) has the potential to impact burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features within Geikie Slide and the Hebridean Slope MPA, through penetration and/or disturbance of the substrate below the surface of the seabed, including abrasion; smothering and siltation rate changes (light); changes in suspended solids (water clarity); removal of target species; and removal of non-target species.

Static demersal fishing (anchored nets/lines, specifically longlining) has the potential to impact burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features within Geikie Slide and the Hebridean Slope MPA, through abrasion/disturbance of the substrate on the surface of the seabed; removal of target species; and removal of non-target species.

The six pressures are considered to have the potential to impact the burrowed mud, offshore deep-sea mud and offshore subtidal sands and gravels features are taken through to Part B of the assessment.