Conservation Advice Package
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RIVER NAVER SPECIAL AREA OF CONSERVATION (SAC) CONSERVATION ADVICE PACKAGE Image: ©Alexander Macdonald, NatureScot Site Details Site name: River Naver Map: https://sitelink.nature.scot/site/8362 Location: Highlands and Islands Site code: UK0030260 Area (ha): 1044.15 Date designated: 17 March 2005 Qualifying features Qualifying feature SCM assessed SCM visit UK overall condition on this site date Conservation Status Freshwater pearl Unfavourable No 12 April 2015 Unfavourable - bad mussel (Margaritifera change margaritifera) [S1029] Atlantic salmon Favourable Recovered 2 August 2011 Unfavourable- (Salmo salar) [S1106] Inadequate Notes: Assessed condition refers to the condition of the SAC feature assessed at a site level as part of NatureScot’s Site Condition Monitoring (SCM) programme. Conservation status is the overall condition of the feature throughout its range within the UK as reported to the European Commission under Article 17 of the Habitats Directive in 2019. Overlapping and linked Protected Areas Parts of the River Naver Special Area of Conservation (SAC) overlap with parts of Caithness and Sutherland Peatlands SAC https://sitelink.nature.scot/site/8218 Caithness and Sutherland Peatlands Special Protection Area (SPA) https://sitelink.nature.scot/site/8476 Altnaharra SAC https://sitelink.nature.scot/site/8187 Altnaharra Site of Special Scientific Interest (SSSI) https://sitelink.nature.scot/site/52 Bad na Gallaig SSSI https://sitelink.nature.scot/site/113 Ben Klibreck SSSI https://sitelink.nature.scot/site/184 Skelpick Peatlands SSSI https://sitelink.nature.scot/site/1436 Syre Peatlands SSSI https://sitelink.nature.scot/site/1512 The River Naver SAC adjoins Cnoc an Alaskie SSSI https://sitelink.nature.scot/site/369 Druim nam Bad SSSI https://sitelink.nature.scot/site/534 Lochan Buidhe Mires SSSI https://sitelink.nature.scot/site/1072 Mallart SSSI https://sitelink.nature.scot/site/1124 Truderscaig SSSI https://sitelink.nature.scot/site/1567 The headwaters of the River Naver SAC also include parts of Loch Meadie Peatlands SSSI https://sitelink.nature.scot/site/1009 Lon a’ Chuil SSSI https://sitelink.nature.scot/site/1091 West Strathnaver SSSI https://sitelink.nature.scot/site/1611 Key factors affecting the qualifying features Freshwater pearl mussel Freshwater pearl mussels are long-lived freshwater molluscs that live in the gravel beds of clear, unpolluted rivers. For part of their lifecycle they are dependent upon a healthy population of salmonids (young salmon or trout) which act as host species. The mussel larvae attach to the gills of salmonid fish in mid to late summer and drop off the following spring. When they detach from their hosts they must land in sandy or gravelly substrates to settle and grow to adulthood. In suitable conditions they can live for over 100 years. However freshwater mussel populations are vulnerable to changes to water quality (including pollution), hydrological alterations (including river engineering and abstractions), habitat degradation of river beds and banks, illegal pearl fishing and availability of host species. The feature has been assessed through NatureScot’s site condition monitoring programme as being in unfavourable condition at this SAC due to the low density of pearl mussels, low levels of juvenile recruitment, water quality targets not being met, spates which have altered the pearl mussel habitat and the legacy of past engineering works which have reduced the area of habitat suitable for pearl mussels. Since the most recent monitoring, the pearl mussel population has also been affected by exceptionally low water levels. Further information about freshwater pearl mussels can be found here. Atlantic salmon Atlantic salmon live in both freshwater and marine environments as part of their lifecycle. They hatch and live in freshwater as juveniles and then migrate to sea as adults. After one year or more at sea the adults return to their natal river to spawn. This homing behaviour has resulted in the development of genetically distinct populations of Atlantic salmon between rivers and several populations may exist within the same river. Atlantic salmon numbers have declined throughout their geographic range, including in Scottish rivers. They may be impacted by a range of pressures in the freshwater and marine phases of their lifecycle. In the River Naver these pressures include: over exploitation, extremely low and high water flows in the river associated with drought and heavy rain in the catchment which may be made worse by rapid run-off from forestry plantations, climate change-related changes to surface water temperature and hydrology, built development (such as transfer of water from the River Vagastie to the Shin hydropower scheme), potential effects of the European minnow (and invasive non-native species) in the catchment, direct and diffuse pollution, gravel extraction from the river bed and potentially inappropriate stocking with young salmon. The river is also vulnerable to the introduction of new species through a number of routes (anglers, canoes, etc) which could have a negative impact. In Scotland Atlantic salmon SACs extend to the tidal limit of rivers only. Marine mortality is however one of the key issues facing Atlantic salmon in Scotland and elsewhere. Environmental factors, climate change, marine developments, enhanced sea lice burdens associated with aquaculture, by-catch in pelagic fisheries, over-exploitation, prey availability and pollution are all key factors that could affect this species when it is in the sea. However, the exact nature of these interactions is not fully understood. The feature has previously been assessed through NatureScot’s Site Condition Monitoring programme as being in unfavourable condition at this SAC due to the low number of salmon in the river. Marine mortality of adult salmon have contributed to this, but the scope of this document covers only those measures that can be taken within the SAC. Management measures are however in place to increase the salmon population through restrictions on the number of fish taken by anglers, including a locally agreed catch-and-release policy. The overall assessment is therefore that the feature is in ‘favourable recovered’ condition. Further information about Atlantic salmon can be found here. Conservation Priorities There is unlikely to be any conflict between management of the Atlantic salmon and freshwater pearl mussel features of the River Naver SAC as both require similar environmental conditions and pearl mussels are dependent on salmon for part of their life cycle. The River Naver SAC partly overlaps with Caithness and Sutherland Peatlands SAC, which has blanket bog as a Priority Feature. The River Naver SAC also overlaps with part of Altnaharra SAC which has a ‘transition mires and quaking bogs’ feature. Broadly similar management is likely to be suitable for these three SACs where there are overlaps, although careful consideration would be needed before planting trees adjacent to the river within Altnaharra SAC or Caithness and Sutherland Peatlands SAC to benefit salmon or freshwater pearl mussel. Any management for the River Naver SAC or assessment of plans or projects will need to take account of the all interests of the Caithness and Sutherland Peatlands SAC, Caithness and Sutherland Peatlands SPA and Altnaharra SAC where the sites overlap. If any management conflicts were to arise between the qualifying features of the River Naver SAC and Caithness and Sutherland Peatlands SAC where the sites overlap, blanket bog should be given priority, followed by any features in unfavourable condition. This is because blanket bog is a Priority Feature and because management to benefit the River Naver SAC could be done outwith Caithness and Sutherland Peatlands SAC. If any management conflicts between the qualifying features of the River Naver SAC and Altnaharra SAC were to arise, priority should be given to Altnaharra SAC where the sites overlap. This is because Altnaharra SAC overlaps with only a small part of the River Naver SAC and management for the benefit of the features of the River Naver SAC could be done elsewhere within this site. Overarching Conservation Objectives for all features of River Naver SAC 1. To ensure that the qualifying features of the River Naver SAC are in favourable condition and make an appropriate contribution to achieving favourable conservation status Favourable Conservation Status (FCS) is considered at a European biogeographic level. When determining whether management measures may be required to ensure that the conservation objectives for this site are achieved, the focus should be on maintaining or restoring the contribution that this site makes to FCS. When carrying out appraisals of plans and projects against these conservation objectives, it is not necessary to understand the status of the feature in other SACs in this biogeographic region. The purpose of the appraisal should be to understand whether the integrity of the site (see objective 2) would be maintained. If this is the case then its contribution to FCS across the Atlantic Biogeographic Region will continue to be met. Further details on how these appraisals should be carried out in relation to maintaining site integrity is provided by objective 2 (including parts a, b, c – and for freshwater pearl mussel - d). If broader information on the feature is available then it should be used to provide context to the site- based appraisal. Note that “appropriate” within this part of