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

Executive Summary

The scope of this fisheries assessment is The Barra Fan and Hebrides Terrace Seamount NCMPA located to the west of Scotland, adjacent boundary with Irish waters, the site follows the seabed as it descends from the top of the Hebridean continental slope down into the Rockall Trough and beyond.

The protected features of the site are burrowed mud (including sea-pens and burrowing megafauna communities), offshore deep-sea muds, offshore subtidal sands and gravels, seamount communities, and orange roughy (Hoplostethus atlanticus). The conservation objective for the NCMPA is to restore the protected features to ‘favourable condition’.

In Part A, fishing activities currently occurring within the site (data from 2015 – 2019) were screened and grouped into aggregated gear types. Throughout this draft fisheries assessment the data from 2015-2019 is referred to as the current levels of activity. The gear types considered relevant to the protected features were demersal trawls, anchored nets/lines (specifically longlines), and pelagic fishing. Based on the pressures associated with these fishing activities and the sensitivity of the protected features, the pressures considered capable of affecting the protected features were identified. These were 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). All six of these pressures were taken through to Part B of the assessment.

In Part B, the assessment of fishing activities capable of affecting the protected features within the site determined that, at current fishing levels, pelagic fishing alone was compatible with the conservation objectives of the site and will not hinder the achievement of the conservation objectives of The Barra Fan and Hebrides Terrace Seamount NCMPA. However, there was the potential that achieving the conservation objectives might be hindered where demersal trawling and anchored nets lines (longline fishing specifically) activities occurred. Scottish Ministers concluded that management measures were required to restrict demersal trawling and longlines within The Barra Fan and Hebrides Terrace Seamount NCMPA.

In Part C, the in-combination assessment considered the residual potential impacts of pelagic fishing alongside other relevant offshore region activities happening in and near the site. Ministry of Defence practice areas overlapped with the site, however these were not thought to interact with the protected features of the site. A disused chemical munitions disposal site is also located on the seabed within the MPA. Due to the age of the disposal site when last in use, it was deemed unlikely to be exerting any current additional pressures on the site and was therefore not considered capable of impacting the protected features. There is no potential for in-combination effects from these activities with pelagic fishing. Scottish Ministers concluded that the remaining fishing activities (pelagic fishing) in-combination with other relevant activities would not hinder the achievement of the conservation objectives for The Barra Fan and Hebrides Terrace Seamount NCMPA.

Considering the need for management measures for demersal trawls and longlines, as identified in the assessment, two management options have been identified and are under consideration by the Scottish Ministers:

• Zoned management would reduce/limit pressures within the site, such as through a partial prohibition to demersal mobile gear and demersal static gears. The following prohibition would be;
  • The exclusion of demersal mobile gears would occur from the entirety of the site where the seamount features occur;
  • The exclusion of all demersal static gears would occur from the entirety of the site where seamount features occur; and
• Zonal exclusion of demersal mobile gears from the depths greater than 800m.

Scottish Ministers do not consider that the introduction of zonal measures would hinder the achievement of the conservation objectives for offshore sands and gravels, burrowed mud, offshore deep-sea muds, seamount communities and orange roughy (Hoplostethus atlanticus) for The Barra Fan and Hebrides Terrace Seamount NCMPA. Rather, these measures would further the achievement of these objectives.

• Full site exclusion of demersal mobile and demersal static gears (including demersal trawls and longlines) across the while site. Scottish Ministers consider that this management option would not hinder the achievement of the conservation objectives for The Barra Fan and Hebrides Terrace Seamount, but rather it would further the achievement of them.

The decision as to which management option is to be taken forward will be made following a statutory public consultation exercise and will be taken in the light of all relevant obligations incumbent upon the Scottish Ministers in relation to the exercise of their functions.