To help target marine nature conservation in Scotland, SNH and JNCC have generated a focused list of habitats and species of importance in Scottish waters - the Priority Marine Features (PMFs). The principal aim of the present investigation was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance in Scottish waters, especially PMFs, but also taking into consideration other importance measures. This was to be achieved through the analysis of seabed video and still photographic imagery collected during research cruises around Scotland in 2009 and 2010, largely by Marine Scotland Science. A further aim was to assess the implications of renewable energy developments on the features of importance, where they occurred in areas likely to experience such developments.
Imagery was analysed from surveys at 15 locations. These included Fair Isle, Westray Firth (Orkney), west of Mainland Orkney, eastern Scapa Flow (Orkney), east of South Ronaldsay (Orkney), in the Sound of Stroma (Pentland Firth), off Noss Head (Caithness), off northwest Lewis, south of the Crowlin Islands (Inner Sound), Kyle Rhea, in the Sound of Canna (Small Isles), east of Mingulay, around Tiree, north of Islay and off the west coast of the Kintyre peninsula.
- Fourteen species and 17 habitats of conservation importance were recorded
- There were firm records of seven species PMFs. Ling Molva molva was recorded amongst rocks at the exposed West Mainland and Lewis locations. The tall seapen Funiculina quadrangularis was found to be abundant at the southern entrance to Kyle Rhea and present, together with the fireworks anemone Pachyceranthus multiplicatus, to the south of the Crowlin Islands at over 200 m and off Mingulay at 95-183 m. The Mingulay area also supported extensive fields of dense northern feather stars Leptometra celtica, widely distributed aggregations of the white cluster anemone Parazoanthus anguicomus, with profuse development on dead coral material, and dense northern sea fans Swiftia pallida at a number of sites in the east of the region. Dense fan mussels Atrina fragilis were recorded in the deep channel (c. 80-170 m) passing through the Sound of Canna.
- Seven habitat PMFs were recorded. A tide-swept Laminaria hyperborea (kelp) park on mixed substrata (IR.MIR.KR.LhypTX.Pk) was recorded at the southern entrance to Kyle Rhea. Burrowed mud habitats with Funiculina quadrangularis were recorded at the southern entrance to Kyle Rhea, south of the Crowlin Islands, and off Mingulay, supporting also Pachycerianthus multiplicatus populations at the latter two sites (SS.SMu.CFiMu.Spn.Meg.Fun), as well as southeast of Tiree, where it appeared a comparatively poor example of the habitat (SS.SMu.CFiMu.Spn.Meg). East Scapa Flow was found to harbour fairly extensive coverage of loose-lying thalli of the red alga Phyllophora crispa on mixed muddy sand (SS.SMp.KSwSS.Pcri) with an apparently low diversity epibiotic community. Mingulay displayed extensive development of deep sponge communities with a fauna including Swiftia pallida and Parazoanthus anguicomus (CR.HCR.DpSp). Cold-water coral Lophelia pertusa reefs were recorded at three sites off Mingulay (SS.SBR.Crl.Lop). Tide-swept beds of horse mussels Modiolus modiolus (SS.SBR.SMus.ModT) were recorded off Noss Head and off Copinsay in the South Ronaldsay survey area. An unusually deep bed of Modiolus, with many of the shells deeply embedded in muddy sand, was recorded at around 120-180 m in the Sound of Canna, with affinities closest to the generally shallow, sheltered biotope, SS.SBR.SMus.ModCvar.
- A number of tide-swept habitats recorded in the Sound of Stroma and Kyle Rhea may be expected to undergo modification from any significant reductions in current speed associated with the development of tidal energy schemes at these locations. Such changes would not necessarily be deleterious, with possible enrichment of low-diversity habitats, especially in the Sound of Stroma.
Acknowledgement: This article was identified by the Crown Estate Wave and Tidal Knowledge Network