Draft Fisheries Assessment – The Barra Fan and Hebrides Terrace Seamount NCMPA: Fisheries management measures within Scottish Offshore Marine Protected Areas (MPAs)

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 affecting the protected features of an NCMPA 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 affecting the protected feature 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 could 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:

• 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.
• 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 affecting the feature; or
  • If it is not possible to determine whether pressure is capable of affecting the feature.

Part B of the assessment considers the potential for activities to affect 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 NCMPA 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. These are 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 The Barra Fan and Hebrides Terrace Seamount 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 The Barra Fan and Hebrides Terrace NCMPA from 2015 – 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.

2.3 Potential pressures exerted by site fishing activities on protected features

According to the JNCC Barra Fan and Hebrides Terrace NCMPA Management Options Paper (2014), the fishing activities considered capable of affecting the protected features are line fishing, set netting and otter trawling. The potential pressures that could be exerted by fishing activities considered capable of affecting the protected features (demersal trawls, anchored nets/lines and pelagic fishing)

The potential pressures that could be exerted by fishing activities considered capable of affecting the protected features (demersal trawls and anchored nets/lines) 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, anchored nets/lines and pelagic fishing 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.

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 protected 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 affecting each feature. Where a pressure from a particular gear is identified as being capable of affecting 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 being capable of affecting a feature but which do interact with the feature are considered in the in-combination aspect of the assessment (Part C).

¹Whilst Environmental Quality Standards (EQS) exist for non-synthetic and synthetic compounds in the marine environment, compliance with these EQS is not considered appropriate to ensure a ‘not sensitive’ scoring in all cases and a Sensitive score is given for all features to reflect concerns that need to be addressed on a site basis.

²In FeAST, ‘physical change (to another seabed type)’ encompasses both change to ‘another seabed type’ and ‘another sediment type’, as defined in the JNCC PAD. *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. Further details on these categories are available in the associated methods document.

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

Pressures that are not relevant to demersal trawls, anchored nets/lines and pelagic fishing (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 & 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 affect the feature.

Of all the pressures considered, six have a 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; removal of non-target species; removal of target species; changes in suspended solids (water clarity); and smothering and siltation rate changes (light). These six pressures are subsequently considered to have the potential to affect the protected features. All six of these pressures are exerted by demersal trawls and anchored nets/lines. Removal of target species and removal of non-target species were the only pressures relevant to pelagic fishing activities and were considered to have the potential to affect the protected 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 affecting the feature but which do interact with the features are considered in the in-combination aspect of the assessment (Part C).

2.5 Part A conclusion

Considering the information on pressures and sensitivity above, demersal trawls and anchored nets/lines have the potential to affect the burrowed mud; offshore subtidal sands and gravels; offshore deep sea mud; orange roughy and seamount communities within The Barra Fan and the Hebridean Terrace Seamount MPA. This is through 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; removal of non-target species; removal of target species; changes in suspended solids (water clarity); and smothering and siltation rate changes (light). Pelagic fishing has the potential to affect the burrowed mud; offshore subtidal sands and gravels; offshore deep sea mud; orange roughy and seamount communities within The Barra Fan and the Hebridean Terrace Seamount NCMPA, through removal of non-target species and removal of target species. The six pressures considered to have the potential to affect the protected features are taken through to Part B of the assessment.