Emu Limited (Emu Ltd.) was commissioned by Scottish Natural Heritage (SNH) to carry out fieldwork to initiate the monitoring of the reef features within the Loch Duich, Loch Long and Loch Alsh candidate Special Area of Conservation (cSAC). The purpose of the fieldwork was to establish a series of relocatable survey transects and single point survey stations at locations which reflected the biological and environmental diversity of the rocky and biogenic reef features of the site. The data acquired from each of these survey stations is to be used to assess the âfavourable conditionâ status of the interest features on future monitoring surveys and provide sufficient information from which a judgement on the existing condition of the interest features can be made.
The Lochs Duich, Long and Alsh (DLA) cSAC is designated for the intertidal and subtidal rocky reefs found throughout the site and biogenic reefs formed by dense beds of horse mussel, Modiolus modiolus. Sub-features of interest for which survey effort was targeted were:
Very sheltered, rocky reefs subject to variable salinity (Loch Long);
Deep sublittoral bedrock cliffs supporting communities characterised by the brachiopods Neocrania anomala, Terabratulina retusa and the anemone Protanthea simplex (Loch Duich),
Dense beds of the normally cryptic brittlestar Ophiopholis aculeata (sills within the centre of Loch system); and
Tide-swept bedrock communities (Kyle Rhea).
Where possible, survey stations were placed in the same location as earlier survey visits to the area in order to allow the current condition of the site to be assessed in relation to information on its former condition.
In addition to this, selected elements of a survey carried out by Heriot-Watt University (HWU) in 1999 on the dense aggregations of the horse mussel Modiolus modiolus within Kyle Akin were repeated. The aim was to directly compare the results from the two surveys to enable an assessment to be made on the condition of the M. modiolus bed.
The following is a summary of the survey work carried out:
MNCR phase 2 surveys along 6 transects comprising littoral (by shore worker) and sublittoral (by diver) sections and one sublittoral transect
MNCR phase 2 surveys by diver at 9 spot locations
estimates of frequency of occurence of dominant/characteristic taxa (by use of replicate quadrats) in biotopes of interest at above locations
MNCR phase 2 surveys by ROV along 12 transects
Modiolus bed surveys by ROV at 6 spot locations