5.2.5. River Tay SAC

                        Site description

  1. At its closest point, the River Tay SAC is located 162.32 km west from the site boundary. The site comprises the longest river in Scotland, originating in western Scotland, flowing easterly across the Highlands before becoming tidal at the Firth of Tay. The River Tay drains a very large catchment, and has the greatest flow of all UK rivers (JNCC, 2024i). The site covers an area of 9,461.63 ha. The site is designated for Annex I habitats and Annex II species including diadromous fish species relevant to this assessment: Atlantic salmon and sea lamprey (NatureScot, 2020g).

                        Feature accounts

                        Atlantic salmon
  1. The ecology of Atlantic salmon is as described above in section 5.2.1, and not repeated here,. The River Tay supports a high-quality Atlantic salmon population, with rod catch returns showing that it is consistently one of the top three salmon rivers in Scotland (JNCC, 2024i). In 1999 the catch was 7,230 fish, over 10% of the Scottish total (JNCC, 2024i). There is considerable ecological variety in the River Tay catchment, resulting in the SAC supporting the full range of salmon life history types found in Scotland, with adult salmon entering the River Tay throughout the year to spawn in different parts of the catchment (JNCC, 2024i).
  2. As stated in paragraph 63, Atlantic salmon numbers have declined throughout their geographic range, including in Scottish rivers. At the River Tay, the proliferation of small scale hydro schemes, Invasive Non Native Species (INNS) such as the North American signal crayfish Pacifastacus leniusculus, and diffuse pollution from agriculture are having a notable impact upon the Atlantic salmon population (NatureScot, 2020g).
                        Sea lamprey
  1. The ecology of sea lamprey is as described above in section 5.2.3, and not repeated here,. At the River Tay, the main issues that may affect sea lamprey are obstructions to passage (e.g. from hydro-schemes), diffuse pollution, and river engineering (NatureScot, 2020g).

                        Conservation objectives

  1. Conservation objectives for the River Tay SAC have been developed by NatureScot as part of a CAP (NatureScot, 2020g). Conservation objectives for all qualifying species features are:
  • to ensure that the qualifying features of River Tay SAC are in favourable condition; and
  • to ensure that the integrity of the River Tay is maintained by meeting objectives 2a, 2b and 2c for each qualifying feature and make an appropriate contribution to achieving FCS (NatureScot, 2020g).
  1. Conservation objectives for Atlantic salmon are as follows:
  • 2a. Maintain the population of Atlantic salmon, including range of genetic types, as a viable component of the site;
  • 2b. Maintain the distribution of Atlantic salmon throughout the site; and
  • 2c. Maintain the habitats supporting Atlantic salmon within the site and availability of food (NatureScot, 2020g).
  1. Conservation objectives for sea lamprey are as follows:
  • 2a. Maintain the population of sea lamprey as viable components of the site;
  • 2b. Maintain the distribution of sea lamprey throughout the site; and
  • 2c. Maintain the habitats supporting sea lamprey within the site, and availability of food (NatureScot, 2020g).
  1. The overarching conservation objectives detailed in paragraph 113 are related to the species-specific conservation objectives 2a to 2c for Atlantic salmon and sea lamprey. The assessment of the Array alone and in-combination with other plans and projects focuses on the individual species-specific conservation objectives. This allows a proportionate approach, as by demonstrating that potential impacts s associated with the Array alone and in-combination with other plans and projects will not have an adverse effect on the species-specific conservation objectives (2a to 2c), the overarching conservation objectives will therefore not be impaired.

                        Condition assessment

  1. The condition of sea lamprey was assessed in 2007 and Atlantic salmon condition was assessed in 2011. The outcomes of these feature condition assessments were as follows:
  • Atlantic salmon: favourable – maintained; and
  • sea lamprey: favourable – maintained (NatureScot, 2020g).

5.2.6. River Spey SAC

                        Site description

  1. At its closest point, the River Spey is located 181.56 km north-west from the site boundary. The site, located in the Highlands and flowing into the Moray Firth, encompasses a total of 5,759.72 ha (NatureScot, 2020f). The site is designated for Annex II species, including diadromous fish features relevant to this assessment: Atlantic salmon, freshwater pearl mussel, and sea lamprey (NatureScot, 2020f).

                        Feature accounts

                        Atlantic salmon
  1. The ecology of Atlantic salmon is as described above in section 5.2.1, and not repeated here. The River Spey supports one of Scotland’s largest Atlantic salmon populations, with little evidence of modification by non-native stocks. Adults spawn throughout the whole length of the river, and good quality nursery habitat is found in abundance in the main river and numerous tributaries. The population includes fish of all ages including migrating smolts and returning adults (JNCC, 2024h). However, the Atlantic salmon population within the River Spey has shown a decrease in the spring multi-sea winter fish since 1952 (NatureScot, 2020f).
                        Freshwater pearl mussel
  1. The ecology of freshwater pearl mussel is as described above in section 5.2.1, and not repeated here,. The River Spey is a large Scottish river which supports a freshwater pearl mussel population in its middle to lower reaches. In parts of the SAC, extremely dense mussel colonies have been previously been recorded and the total population was once estimated at several million (JNCC, 2024h).
  2. In the River Spey, Atlantic salmon seem to be the most used host species for freshwater pearl mussel larvae (NatureScot, 2020f). Within the River Spey SAC, it is likely that freshwater pearl mussels have an artificially low population due to historic unsustainable fishing (NatureScot, 2020f).
                        Sea lamprey
  1. The ecology of sea lamprey is as described above in section 5.2.3, and not repeated here,. The River Spey represents the most northern part of the sea lamprey’s range in the UK, as the species is absent from rivers north of the Great Glen, and the River Spey is virtually at its northern limit (JNCC, 2024h). Recent surveys show that sea lamprey larvae are widely distributed throughout the middle and lower reaches of the river, where the particularly fast-flowing waters of the River Spey provide ideal spawning conditions for this species (JNCC, 2024h).

                        Conservation objectives

  1. Conservation objectives for the River Spey SAC have been developed by NatureScot as part of a CAP (NatureScot, 2020f). Conservation objectives for all qualifying species features are:
  • to ensure that the qualifying features of River Spey SAC are in favourable condition and make an appropriate contribution to achieving FCS; and
  • to ensure that the integrity of the River Spey SAC is restored by meeting objectives 2a, 2b and 2c for each qualifying feature (and 2d for freshwater pearl mussel) (NatureScot, 2020f).

 

  1. Conservation objectives for Atlantic salmon are as follows:
  • 2a. Restore the population of Atlantic salmon, including range of genetic types, as a viable component of the site;
  • 2b. Restore the distribution of Atlantic salmon throughout the site; and
  • 2c. Restore the habitats supporting Atlantic salmon within the site and availability of food (NatureScot, 2020f).
  1. Conservation objectives for freshwater pearl mussel are as follows:
  • 2a. Restore the population of freshwater pearl mussel as a viable component of the site;
  • 2b. Restore the distribution of freshwater pearl mussel throughout the site;
  • 2c. Restore the habitats supporting freshwater pearl mussel within the site and availability of food; and
  • 2d. Restore the distribution and viability of freshwater pearl mussel host species and their supporting habitats (NatureScot, 2020f).
  1. Conservation objectives for sea lamprey are as follows:
  • 2a. Maintain the population of sea lamprey as a viable component of the site;
  • 2b. Maintain the distribution of sea lamprey throughout the site; and
  • 2c. Maintain the habitats supporting sea lamprey within the site and availability of food (NatureScot, 2020f).
  1. The overarching conservation objectives detailed in paragraph 123 are related to the species-specific conservation objectives 2a to 2c for Atlantic salmon and sea lamprey and 2a to 2d for freshwater pearl mussel. The assessment of the Array alone and in-combination with other plans and projects focuses on the individual species-specific conservation objectives. This allows a proportionate approach, as by demonstrating that potential impacts s associated with the Array alone and in-combination with other plans and projects will not have an adverse effect on the species-specific conservation objectives (2a to 2c/2d), the overarching conservation objectives will therefore not be impaired.

                        Condition assessment

  1. The condition of Atlantic salmon and sea lamprey were assessed in 2011 and freshwater pearl mussel condition was assessed in 2014. The outcomes of these feature condition assessments were as follows:
  • Atlantic salmon: unfavourable – recovering;
  • freshwater pearl mussel: unfavourable – declining; and
  • sea lamprey: favourable – maintained (NatureScot, 2020f).
  1. Atlantic salmon was assessed as being in unfavourable condition at this SAC due to a decline in the number of salmon in the river, especially the spring salmon component of the population. The main issues include marine survival, water abstraction, dams and weirs, predation, and invasive non-native species. Marine mortality of adult salmon was also suggested as potentially contributing to the decline, but the scope of the CAP only covered measures that can be taken within the SAC (NatureScot, 2020f).
  2. Freshwater pearl mussel monitoring in the River Spey SAC showed a significant apparent decrease in mussel density between 2000 and 2014. The small and isolated populations in the upper Spey were not recruiting and some appeared to have disappeared. Mussels are not successfully recruiting at an adequate density to maintain the population upstream of Grantown on Spey. As a result the site is in unfavourable condition for this feature (NatureScot, 2020f). The lack of recruitment in the upper Spey may be due to fine sediment causing anoxic conditions in the river gravels, which immature mussels cannot tolerate. Another issue could be poor water quality as there is lower flow in the upper river, and therefore less dilution (NatureScot, 2020f). Further, water crowfoot Ranunculus fluitans has been found to impact freshwater pearl mussels in the middle and lower Spey. This occurs through entanglement of mussels within the roots of water crowfoot, and smothering due to trapped sediment within these roots (NatureScot, 2020f).

5.2.7. Berriedale and Langwell Waters SAC

                        Site description

  1. At its closest point, the Berriedale and Langwell Waters SAC is located 219.57 km north-west from the site boundary. The site, located in the Highlands and flowing into the Moray Firth, encompasses 58.25 ha (JNCC, 2024a). The site is designated solely for Atlantic salmon.

                        Feature accounts

                        Atlantic salmon
  1. The ecology of Atlantic salmon is as described above in section 5.2.1, and not repeated here,. The Berriedale and Langwell Waters SAC support small, but high-quality Atlantic salmon populations. The SAC is comprised of two comparatively small rivers and only supports a small proportion of the Scottish Atlantic salmon resource. However, their long history of low management intervention means that they score highly for naturalness. Recent records indicate that the full range of Atlantic salmon life-history types return to the river, with grilse, spring and summer salmon all being caught (JNCC, 2024a).

                        Conservation objectives

  1. Conservation objectives for the Berriedale and Langwell Waters SAC have been developed by NatureScot as part of a CAP (NatureScot, 2020b). Overarching conservation objectives for this SAC are:
  • to ensure that the qualifying feature of Berriedale and Langwell Waters SAC is in favourable condition and makes an appropriate contribution to achieving FCS;
  • to ensure that the integrity of Berriedale and Langwell Waters SAC is maintained by meeting objectives 2a, 2b and 2c for Atlantic salmon (NatureScot, 2020b).
  1. Specific Atlantic salmon conservation objectives for Atlantic salmon are as follows:
  • 2a. Maintain the population of Atlantic salmon, including range of genetic types, as a viable component of the site;
  • 2b. Maintain the distribution of the species throughout the site; and
  • 2c. Maintain the habitats supporting the species within the site and availability of food (NatureScot, 2020b).
  1. The overarching conservation objectives detailed in paragraph 133 are related to the species-specific conservation objectives 2a to 2c for Atlantic salmon. The assessment of the Array alone and in-combination with other plans and projects focuses on the individual species-specific conservation objectives. This allows a proportionate approach, as by demonstrating that potential impacts s associated with the Array alone and in-combination with other plans and projects will not have an adverse effect on the species-specific conservation objectives (2a to 2c), the overarching conservation objectives will therefore not be impaired.

                        Condition assessment

  1. The condition of Atlantic salmon was assessed in 2011 as:
  • Atlantic salmon: favourable – maintained (NatureScot, 2020b).

5.2.8. River Teith SAC

                        Site description

  1. At its closest point, the River Teith SAC is located 244.19 km south-west from the site boundary. The river begins in Loch Lomond and the Trossachs National Park and flows through Stirling and into the Firth of Forth. The SAC encompasses 1,289.33 ha and is designated for Annex II diadromous fish species, including Atlantic salmon and sea lamprey, which are relevant to this assessment (NatureScot, 2015).

                        Feature accounts

                        Atlantic salmon
  1. The ecology of Atlantic salmon is as described above in section 5.2.1, and not repeated here,. Atlantic salmon are present as a qualifying feature of this SAC, but not a primary reason for site selection. This, in combination with no CAP available for this site, results in a lack of site-specific information about this species. However, it is noted in Standard Data From for this SAC that it is considered to support a significant presence of Atlantic salmon (JNCC, 2015).
                        Sea lamprey
  1. The ecology of sea lamprey is as described above in section 5.2.3, and not repeated here,. The River Teith in eastern Scotland represents part of the sea lamprey’s eastern range. The River Teith is the most significant tributary of the River Forth and young sea lampreys have been recorded throughout the lower reaches of the main river. The conservation importance of the River Teith is increased by the fact that, unlike many British rivers, it supports populations of all three lamprey species (including river lamprey and brook lamprey which are out with the scope of this RIAA) (JNCC, 2024j).

                        Conservation objectives

  1. A CAP has not yet been published for the River Teith SAC. However, conservation objectives for all qualifying species have been defined to avoid deterioration of their habitats or significant disturbance to the qualifying species, thus ensuring that the integrity of the site is maintained, and that the site makes an appropriate contribution to achieving FCS for each of the qualifying species. The following conservation objectives are to be maintained in the long term for the qualifying species:
  • the population of the species, including range of genetic types for Atlantic salmon, as a viable component of the site;
  • the distribution of the species within site;
  • the distribution and extent of habitats supporting the species;
  • the structure, function and supporting processes of habitats supporting the species; and
  • there is no significant disturbance of the species (NatureScot, 2015).
  1. Conservation objectives specific to Atlantic salmon and sea lamprey (e.g. 2a, 2b, and 2c) were not provided  (NatureScot, 2015).

                        Condition assessment

  1. As stated in paragraph 37, there was no CAP available for the River Teith SAC at the time of writing, and therefore no condition assessments were available for Atlantic salmon and sea lamprey.

5.2.9. River Oykel SAC

                        Site description

  1. At its closest point, the River Oykel is located 259.33 km north-west from the site boundary. The site is in the Highlands and flows into the Moray Firth. The SAC encompasses 921.46 ha and is designated solely for Annex II Atlantic salmon and freshwater pearl mussel (NatureScot, 2020d).

                        Feature accounts

                        Atlantic salmon
  1. The ecology of Atlantic salmon is as described above in section 5.2.1, and not repeated here,. As stated in paragraph 63, Atlantic salmon numbers have declined throughout their geographic range, including in Scottish rivers. In the River Oykel, potential pressures to Atlantic salmon include: overexploitation, loss of habitat connectivity, habitat degradation, climate change-related changes to surface water temperature and hydrology, built development (such as hydropower on the River Cassley and a weir on the Tutim Burn which is a barrier to salmon reaching apparently suitable habitat upstream) and direct and diffuse pollution and inappropriate stocking with young salmon in the past (NatureScot, 2020d).
                        Freshwater pearl mussel
  1. The ecology of freshwater pearl mussel is as described above in section 5.2.1, and not repeated here,. The River Oykel supports a high-quality freshwater pearl mussel population with high densities recorded at some locations, including a bed numbering several thousand individuals. There is also evidence of non non-surveyed populations in deep water that may increase the conservation importance of the river (JNCC, 2024f).

                        Conservation objectives

  1. Conservation objectives for the River Oykel SAC have been developed by NatureScot as part of a CAP (NatureScot, 2020d). Conservation objectives for all qualifying species features are:
  • to ensure that the qualifying features of River Oykel SAC are in favourable condition and make an appropriate contribution to achieving FCS; and
  • to ensure that the integrity of the River Oykel SAC is restored by meeting objectives 2a, 2b, 2c for both features (and 2d for freshwater pearl mussel) (NatureScot, 2020d).
  1. Conservation objectives for Atlantic salmon are as follows:
  • 2a. Restore the population of Atlantic salmon, including range of genetic types, as a viable component of the site;
  • 2b. Maintain the distribution of Atlantic salmon throughout the site; and
  • 2c. Maintain the habitats supporting Atlantic salmon within the site and availability of food (NatureScot, 2020d).

 

  1. Conservation objectives for freshwater pearl mussel are as follows:
  • 2a. Restore the population of freshwater pearl mussel as a viable component of the site;
  • 2b. Restore the distribution of freshwater pearl mussel throughout the site;
  • 2c. Restore the habitats supporting the freshwater pearl mussel within the site and availability of food; and
  • 2d. Maintain the distribution and viability of freshwater pearl mussel host species and their supporting habitats (NatureScot, 2020d).
  1. The overarching conservation objectives detailed in paragraph 146 are related to the species-specific conservation objectives 2a to 2c for Atlantic salmon and 2a to 2d for freshwater pearl mussel. The assessment of the Array alone and in-combination with other plans and projects focuses on the individual species-specific conservation objectives. This allows a proportionate approach, as by demonstrating that potential impacts associated with the Array alone and in-combination with other plans and projects will not have an adverse effect on the species-specific conservation objectives (2a to 2c/2d), the overarching conservation objectives will therefore not be impaired.

                        Condition assessment

  1. The condition of Atlantic salmon was assessed in 2011 and freshwater pearl mussel condition was assessed in 2015. The outcomes of these feature condition assessments were as follows:
  • Atlantic salmon: favourable – recovered;
  • freshwater pearl mussel: unfavourable – no change (NatureScot, 2020d).
  1. Freshwater pearl mussel has been assessed as being in unfavourable condition at this SAC due to the low number and density of individuals present, low levels of juvenile recruitment, water quality, water flow and disturbance of mussel beds through illegal pearl fishing (NatureScot, 2020d).