2001 Scottish Natural Heritage (SNH) Loch Sunart sublittoral habitats joint broad-scale mapping survey
A comprehensive biotope mapping survey of the sublittoral habitats was undertaken in July and August 2001, by a collaborative research group comprising staff from the University of St Andrews, Herriot Watt University and SNH. Rapid broadscale remote acoustic mapping techniques were utilised and "groundtruth" data were collected to enable to interpretation of acoustically classed seafloor maps. Groundtruthing data were collected in the field using a range of sampling techniques including diver-based observations with video and still cameras (20 stations), video imagery collected by remotely operated vehicle (ROV, 52 stations) and grab sampling of sedimentary habitats (16 stations).
dataset
GB-SCT-SNH-ME-000069-MRSNH00100000004-LS
eng
urn:ogc:def:crs:EPSG::4326
Bates, C. R., Moore, C. G., Harries, D. B., Austin, W. and Lyndon, A. R. (2004). Broad scale mapping of sublittoral habitats in Loch Sunart, Scotland. Scottish Natural Heritage Commissioned Report No. 006 (ROAME No. F01AA401C).
geoscientificInformation
biota
biota
revision
2008-01-06
revision
2009-11-16
creation
2011-01-20
creation
2011-02-16
creation
2003-01-01
creation
2011-07-06
creation
2012-03-16
creation
2012-05-25
revision
2005-04-27
creation
2006-08-31
creation
2017-05-12
-6.0226
-5.4774
56.7377
56.6011
creation
2009-06-18
Minches & Western Scotland
revision
2010-01-01
circalittoral
2001-07-25
2001-08-04
publication
2003-01-03
notPlanned
Detailed information on data collection and processing can be accessed: Bates, C. R., Moore, C. G., Harries, D. B., Austin, W. and Lyndon, A. R. (2004). Broad scale mapping of sublittoral habitats in Loch Sunart, Scotland. Scottish Natural Heritage Commissioned Report No. 006 (ROAME No. F01AA401C). Diver survey: MNCR phase II diving surveys were carried out at 20 stations, direct recording being supplemented with diver video at 12 stations. The level of survey quality was set as adequate for both flora and fauna. MNCR survey, site and habitat forms were completed. N.B. it is this MNCR data (20 stations) that is currently present in this Marine Recorder Survey. In order to map the distribution of Limaria hians in the Laudale Narrows area, abundance was assessed at 21 stations. These were initially marked with buoyed shot lines and positions fixed. At each station abundance was assessed by a diver using a 0.25m2 quadrat with a grid of cross strings at 5cm intervals. The diver recorded the number of string intersections (from a toal of 16) that lay immediately above L. hians nest material. At each station 10 replicate measures were made from randomly placed quadrats. In addition a 5cm long sediment core of 4cm diameter was taken and notes made of depth, sediment type, brittlestar coverage and kelp species and coverage. N.B. the L. hians data does not appear to have been entered into Marine Recorder. ROV sampling: deployed at 27 stations, using dGPS for position fixing. Digital Video footage was recorded at each station for 5-10 minutes at each station. At 25 stations the ROV was used to record biotope zonation, with video recording for 10-20 minutes at each station. N.B. this data does not appear to have been entered into Marine Recorder. Grab sampling: Samples for macrobenthic infauna were taken at 16 stations iusing asingle 0.1m2 Van Veen grab samples were taken. A subsample of around 100-150ml of sediment was taken from each sediment sample for grain size analysis before sieving the remainder through a 0.5mm mesh. The screenings were buffered on 10% formalin, the screeings were preserved in borax-buffered 10% formalin. N.B. this data does not appear to have been entered into Marine Recorder. Acoustic survey: Bathymetric sidescan and single beam acoustic mapping techniques were used at near 100% coverage to develop acoustically classed seafloor maps. AGDS and sidescan data were simultaneously acquired. A Furuno FCV292 dual frequency echosounder with 28kHz and 200kHz transducers and a Lowrence 300A with 50 kHz transducers. The use of alternative frequencies with different echosounders was undertaken in order to test AGDS methods for discriminating particular biotopes. The bathymetric sidescan used was a Submetricx System 2000 with 117kHz transducers. Acquisition settings varied with transmit lengths of 18-100cps (77-424?sec), a ping rate of 3-5 per second and 2048 sample receiver length. Sound velocity measurements were acquired at the site but no depth stratification was noted and thus velocities of 1498ms-1 were used for ray tracing throughout the site. The transducers were bow-mounted on the survey vessel with the motion reference unit permanently fixed immediately above the transducers. The motion reference unit was a TSS DMS-05 dynamic motion sensor which used solid state sensing elements to measure instantaneous linear accelerations and angular rates of motion change to 0.05°. Differential global positioning system (dGPS) was used alnog with a fluxfate magnetic compass. Survey line spacing was chosen to give a minimum 50% overlap on bathymetric sidescan data, and was further reduced where sea floor change was rapid or of important interest. AGDS was calibrated for depth, E1 and E2 values. Sidescan was roll calibrated. Tidal corrections were applied to both the bathymetric sidescan data and ADGS from 10 minute tidal curves modelled using information from Admiralty Tide tables and the Hydrographic Office
Not for navigational use; 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
University of St. Andrews, School of Geography and Geoscience
originator
Consultant
Colin Moore
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
2024-06-21