Scottish Natural Heritage (SNH) Sound of Arisaig SAC Site Condition Monitoring
The principal purpose of the study was to carry out site condition monitoring of the of the inshore sublittoral sediment habitats of the Sound of Arisaig SAC, in order to identify any deterioration in the condition of the subtidal sandbank feature and to form a judgement on its current condition. The approach taken to achieve this aim is to perform an extensive drop-down video survey and a grab survey of the component habitats of the feature. Characterisation of the subsurface fauna and sediment composition of the main sediment biotopes is performed by means of grab sampling. Detailed surveying of the sea bed and subsurface communities at selected maerl bed sites is carried out using diving techniques.
series
GB-SCT-SNH-CMEU-SCM-SoA
eng
urn:ogc:def:crs:EPSG::4326
biota
biota
revision
2008-01-06
revision
2009-11-16
creation
2011-02-16
creation
2011-07-06
creation
2006-08-31
creation
2017-05-12
-5.9670
-5.6665
56.9024
56.7328
creation
2009-06-18
Minches & Western Scotland
creation
2009-05-01
42E4
2003-07-05
2022-11-24
publication
2004-05-31
notPlanned
The SCM work is divided into three stages: 1) Dropdown Video: Knowledge of the distribution, diversity and extent of biotopes was gained by performing a stratified random sampling drop-down video survey, supplemented by a limited amount of focussed sampling. To promote adequate coverage of the different regions within the cSAC, the survey area between the 0m and 20m contours was split up into 20 strata. 150 stratified random sampling stations were selected. At each station the video is deployed briefly from a drifting vessel, noting the times, depths and precise positions at the start and end of the drift. The runs averaged 4 minutes duration and 50m in length. In addition to the 150 stratified random sample sites, a farther 53 drop-down video sites are worked to provide coverage of the deeper areas, to fill in any perceived geographical gaps in the random samples, and to position sites in the vicinity of locations previously surveyed by others. At a small number of sites where navigation was difficult, the dropdown system is replaced by diver-held video. 2) Grab Survey: Following categorisation of sample stations on the basis of biotope, sample stations representative of the different sedimentary biotopes are selected for analysis of the infauna and sediment composition by grab sampling at 20 stations. At each station a single 0.1m2 van Veen grab sample was collected using the vessel RV Serpula. A subsample of c.150ml sediment was taken from the surface of the grab contents for particle size analysis and the remaining material sieved on a 1mm mesh screen, the sievings being retained in borax-buffered 5% formalin. 3) Maerl Survey: Five maerl sites were selected for detailed examination of the infauna and epibiota by diver using MNCR phase 2 survey methodology along a 25m belt transect. A band 2m either side of the tape was surveyed by two divers, one on each side, who noted the presence, and where possible, estimates of the abundance of conspicuous biota, collecting material which needed to be identified in the laboratory. To supplement the real-time visual records and collections, the transect band was videoed using a hand-held digital video camera (Sony DCR-TRV900 in an Amphibico Navigator 900 housing) and at some sites still photographs taken of the maerl and associated community using two digital still cameras. In areas of living maerl, 4 replicate core samples using a 10.3cm diameter corer to a depth of 20cm are taken (using MNCR Phase II methods) for infaunal analysis, and an additional 20cm sediment core of 5cm diameter was taken for grain size analysis. The areal extent of these maerl beds beyond the 25m transect is also assessed by performing drop-down video surveys at stations along lines radiating out from the station marker.
publication
2011-02-02
true
See the referenced specification
publication
2018-01-23
true
See the referenced specification
Not suitable for use in navigation; SNH copyright data which is available for re-use under government licence terms: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
no restrictions to public access
Data Manager
Scottish Natural Heritage (SNH), Headquaters
Great Glen House, Leachkin Road
Inverness
IV3 8NW
01463 725000
originator
Data Manager
Scottish Natural Heritage (SNH), Headquaters
Great Glen House, Leachkin Road
Inverness
IV3 8NW
01463 725000
custodian
Data Manager
Scottish Natural Heritage (SNH), Headquaters
Great Glen House, Leachkin Road
Inverness
IV3 8NW
01463 725000
pointOfContact
2022-11-24