North Coast SMR

This section summarises the information from the Marine Protected Areas (MPAs) and intertidal and continental shelf habitats assessments from SMA2020. It also provides information from the relevant case studies relating to Priority Marine Features (PMFs), with a focus on habitats.  Further work is required to enable assessment at a regional scale for most species; this will be included in Scotland’s next marine assessment.

At a regional scale for MPAs the focus is on the number of new MPAs, MPAs with new spatial management measures, and MPAs in which spatial management measures are in discussion, as well as recognising monitoring that has been undertaken between 2012-2018.  For the marine habitats, the focus is on interpreting the relevant intertidal and continental shelf habitat assessments – biogenic habitats, predicted extent of physical disturbance to the seafloor (BH3) and intertidal seagrass beds.  For PMFs, a summary is provided of the changes in our understanding of the habitats of most relevance to the SMR, including changes in distribution and extent.

Marine Protected Areas

Progress in developing the Scottish MPA network

There are three MPAs in the North Coast SMR that contribute to the Scottish MPA network (see Table 1).  Some of these MPAs overlap completely or partially in terms of their spatial coverage and/or the features (habitats, species, etc.) they were set up to help conserve.  They are counted as separate MPAs because they have been established under different legislation which influences the way in which they are managed.  Also note that there are MPAs that straddle the boundaries between different SMRs.  Where this is the case, these MPAs have been counted as contributing to the MPA network in all of the SMRs/OMRs in which they are present.  This means that the total number of MPAs in Scotland cannot be calculated through combining the regional totals.  Please see the Marine Protected Area assessment which contains statistics for the Scottish MPA network as a whole.  

Table 1. Numbers of types of MPAs in the North Coast SMR that contribute to the Scottish MPA network, including the number of new MPAs introduced since 2012.

The MPAs are focused on the protection of breeding seabirds, otters and offshore reefs.

The North Caithness Cliffs SPA and Cape Wrath SPA, situated at the north-easternmost and north-westernmost respectively extremities of mainland Scotland, support internationally important numbers of breeding seabirds, especially gulls and auks.  During the breeding season, these seabirds forage over large areas of sea returning frequently with food to feed their chicks.  Durness SAC is designated for the population of otters that frequent the coast.

Progress in managing MPAs

The progress in implementing management for MPAs in the North Coast SMR is summarised in Table 2.  This includes information on where spatial management measures are in place and where they are under discussion.  It also includes information on the number of MPAs that have been monitored, whether by statutory bodies or through citizen science.

Table 2. Summary of progress in managing Marine Protected Areas in the North Coast SMR

Note that the spatial measures listed in the table are in addition to the protection provided as a result of consideration of activities/developments through licensing and consenting processes.

There are currently no spatial measures in place or under discussion for any of the MPAs in this SMR.  All of the MPAs have been monitored at least once during the assessment period with the main focus on breeding seabirds.

Information on MPA boundaries can be viewed in Marine Scotland’s NMPi. To find out more about specific MPAs, please visit NatureScot’s SiteLINK. 

Intertidal and continental shelf habitats

SMA2020 contains three relevant habitat assessments: intertidal seagrass beds, subtidal biogenic habitats, and predicted extent of physical disturbance to seafloor.  Assessment of the status of subtidal biogenic habitats is based on temporal reductions in extent of six habitat types: seagrass beds, serpulid aggregations, flame shell beds, maerl beds and horse and blue mussel beds.  Although blue mussel beds, horse mussel beds, maerl beds and seagrass beds have been recorded within the SMR, no data are available on temporal changes in extent of these habitats and hence no status assessments could be made;  the other biogenic habitats i.e. serpulid aggregations, flame shell beds and intertidal seagrass beds have not been recorded in this SMR.  Modelling work was carried out as part of the assessment to predict the extent of physical disturbance to the seafloor more generally.

Predicted physical disturbance to the seafloor

To assess physical disturbance to seafloor habitats SMA2020 employed a modelling approach which generates a map of predicted relative disturbance levels from demersal fishing activity on a scale of 0 (zero) to 9 (severe).  The map was produced by the combination of information on the distribution of habitats, the sensitivity of the habitats (and species present to varying degrees) and the fishing pressure from demersal trawling, dredging and seine netting.  Fishing pressure information was derived from Vessel Monitoring System (VMS) data from 2012 - 2016 and was categorised as either surface abrasion (disturbance of surface and upper layers of sediment) or sub-surface abrasion (disturbance to a depth of >3 cm).  The final predicted disturbance index utilises the greater of these two pressure values and for descriptive purposes has been categorised as no disturbance (0), low disturbance (1-4) and high disturbance (5-9).

It should be emphasised that this method does not measure disturbance to seabed habitats, but predicts relative levels of disturbance. These relative levels are dependent upon the accuracy of habitat data and sensitivity assessments.  Many of the habitat data are derived from modelling and there is a low level of confidence in its accuracy.  Geographical variation in the accuracy of the sensitivity information employed is likely to be great, being dependent upon the level and quality of information used locally.  A significant limitation of the method is that during the assessment period pressure data were only available for vessels >12 m, which has probably resulted in an underestimation of disturbance.

Predicted habitat disturbance by mobile demersal fishing for the North Coast SMR is close to the average for SMRs in terms of the proportion of the seabed with 49% high disturbance compared to the average of 50% for all SMRs (Figure X).  Only 5% of the seabed is predicted to experience no disturbance (average of 12% for all SMRs).  Disturbance levels closely mirror the degree of surface abrasion and are relatively heavy in the central part of the SMR where the substrate is predominantly sand, and lighter towards the eastern and particularly western side where coarse sediments predominate. 

Figure 3.  Predicted physical disturbance to the seafloor in the North Coast SMR and prohibition areas for all mobile demersal fishing. 

Priority Marine Features and birds (non-PMF)

Overview of recorded PMFs and birds

The North Coast SMR supports a range of PMFs and breeding seabirds as well as wintering waterbirds (i.e. waders, estuarine waterfowl, seaduck and coastal water feeding birds) as detailed in Table 3. 

Table 3: Details of PMFs, seabirds, and wintering waterbirds found in the North Coast SMR

There are 43 PMFs and 33 marine birds recorded in this region.  The North Coast SMR supports a number of benthic PMFs at the limit of their recorded distribution, which are more commonly found on the west coast.  Loch Eriboll supports a number of PMFs, such as seagrass beds and maerl beds, which are not found elsewhere in the SMR. Six cetacean species occur regularly in the Pentland Firth, namely harbour porpoise, minke whale, white-beaked dolphin, Risso’s dolphin, killer whale, and bottlenose dolphin with a further four species that normally inhabit more offshore waters as casual visitors: short-beaked common dolphin, Atlantic white-sided dolphin, long-finned pilot whale and sperm whale. Together with otters and harbour and grey seals the Pentland Firth supports one of the highest numbers of PMF mammal species, making it one of richest areas in the UK.

Progress in understanding intertidal and continental shelf habitats listed as PMFs

There are relatively few records of PMF habitats in the North Coast SMR, either before or during the assessment period of between 2012-2018.  These records are focused in Loch Eriboll and the Kyle of Tongue.

The temporal sequence of records of all PMF habitats is provided in Table 4, based on inclusion in the Marine Recorder (2021) and GeMS (2021) databases, as well as identified additional sources.  Associated commentary, however, is restricted to PMFs for which the information has the potential to inform regional marine planning (see Figure 4 for their distribution).  For example, some PMFs are excluded on the basis that they are very widely distributed and for which the records represent a small proportion of their likely distribution, such as several of the kelp habitats.

The contribution of citizen science records has fallen slightly from the pre-2012 level of 23% to 16% in later years (Table 4).  Overall, there has been little identification of PMF habitats in the SMR since 2012, with the notable exception of records from an unpublished report resulting from a 2019 diving survey of Loch Eriboll and the Kyle of Tongue (Thouless, to be published).

PMF records in the SMR are largely restricted to Loch Eriboll and its approaches.  There are no post-2012 records and only sparse pre-2012 records of the biogenic habitats, blue mussel beds and seagrass beds.  Burrowed mud is widely distributed in the sheltered conditions of Loch Eriboll, with all records derived from Marine Scotland and SNH surveys in 2011 and 2012 (Moore, 2012; Moore & Atkinson, 2012) and the 2019 diving survey (Thouless, to be published)).  The latter also recorded previously unknown locations for a maerl bed and patches of 'maerl or coarse shell gravel with burrowing sea cucumbers' in Loch Eriboll, and a sparse horse mussel bed and tide-swept algal communities within and around the Kyle of Tongue.

Table 4.  Temporal frequency of PMF habitat records within the North Coast SMR obtained from GeMS (2021), Marine Recorder (2021) and other sources.  The numbers of All records are given, as well as those from Citizen Science (CS) surveys alone.

Figure 4.  Temporal pattern of records of selected PMF habitats for the North Coast SMR, with inset showing location of main map and additional PMF records outside Loch Eriboll.

Status and trend in grey and harbour seals

The North Coast SMR is included in the Orkney and North Coast seal management area and as such there are not specific assessments of the status and trends in grey and harbour seals in this SMR.  Within the combined Orkney Islands and North Coast SMRs the number of grey seals is stable and their status is assessed as ‘few or no concerns’.  Harbour seal numbers were high and stable until the early 2000s but from 2005 onwards their numbers have been steadily declining and their status is assessed as ‘many concerns’.