Habitat point records from 1989 MNCR Loch Sunart survey

This survey was undertaken to describe the range of habitats and associated communities of species in sublittoral areas of Loch Sunart and Loch Teacuis. Loch Sunart lies between the Ardnamurchan and Morvern Peninsulas on the west coast of Scotland. It is a narrow fiordic sea loch some 31 km long with six basins, with a greatest depth of 124 m below Chart Datum (BCD). Wave exposure varies from 'moderately exposed' to 'extremely sheltered'. 'Moderate' tidal streams occur within narrow sections of the loch. Shallow sublittoral habitats are predominantly steeply sloping bedrock and boulders with sediment in deeper water and in sheltered bays. Loch Teacuis bisects Morvern Peninsula entering the south shore of Loch Sunart via two narrow, shallow channels either side of the island of Carna. Three sills divide the loch into basins, the maximum depth is 31 m BCD. Loch Teacuis is 'extremely sheltered' from wave action, tidal streams are weak over the sills. Littoral habitats are predominantly rocky while sublittoral habitats are sedimentary with small stones in the narrows. A total of 82 habitats at 29 sites were surveyed. Analysis of these data produced 1 littoral and 15 sublittoral habitat and associated community types. Infralittoral habitats were dominated by kelp with a turf of foliose algae on rock surfaces below the kelp canopy. In the outer basin and in the outer narrows, the kelp Laminaria hyperborea was the dominant species. In more sheltered areas, the kelp Laminaria saccharina dominated infralittoral habitats. Circalittoral rock habitats in the outer basin and outer narrows were steeply sloping, vertical in places, and characterised by erect sponges, hydroids, anemones and sea squirts. Many species recorded are more characteristic of open coast habitats. In more sheltered areas, circalittoral bedrock and boulder habitats were characterised by the anemone Protanthea simplex and the brachipod Neocrania anomala with brittlestars, crustaceans and sea squirts also common. Extensive beds of the brittlestars Ophiothrix fragilis and Ophiocomina nigra were recorded in areas of weak tidal flow. Sedimentary habitats in the outer loch and central narrows were predominantly sandy mud characterised by the sea pen Virgularia mirabilis and the burrowing anemone Cerianthus llyodii. In very sheltered areas, deep habitats were soft mud characterised by the sea whip Funiculina quadrangularis and the Dublin Bay prawn Nephrops norvegicus. The conservation importance of Loch Sunart and Loch Teacuis has been assessed according to 14 criteria. Habitats, associated communities and species have been provisionally assessed to be of international, national, regional or local importance. Records currently considered sensitive have been removed from this dataset.