2009 Scottish Natural Heritage (SNH) North Rona broad scale mapping survey
The purpose of this broad scale mapping (BSM) study was to obtain an estimation of the geographic distribution and extent of the qualifying biological resources (habitats and their associated biological communities – biotopes) within the protected area in order that a comprehensive management plan can be developed for North Rona marine SAC. The survey area encompasses the seabed all around North Rona. BSM was conducted in two phases: 1) an acoustic survey; 2) a ground-truthing survey through camera deployments (video and still photography). The aim of the acoustic element of the survey was to identify different backscatter returns and describe, as well as delineate, the extent of the various seabed habitat types occurring around North Rona. A digital sidescan sonar mosaic, in conjunction with single beam echo sounder derived bathymetry, provided the initial broadview to map the substrata present throughout the survey area as well as allowing the identification of any features of interest. The aim of the ground-truthing element of the survey was to provide a description of the richness and diversity of the habitats on both rocky reef and the softer sediments. The biotope distribution and species composition was developed through interpretation of dropdown video footage and digital still photography, taken after evaluation of the sidescan mosaic. All survey operations were conducted by contractors Seastar Survey Ltd from their vessel SV Otarie.
dataset
GB-SCT-SNH-ME-000119-MRSNH01600000006-NRona
http://www.nature.scot
eng
urn:ogc:def:crs:EPSG::27700
Axelsson, M., Dewey, S. and Doran, J. (2010). Broad scale mapping of the North Rona Special Area of Conservation (SAC). Scottish Natural Heritage Commissioned Report No 386.
elevation
geoscientificInformation
biota
inlandWaters
imageryBaseMapsEarthCover
oceans
biota
revision
2008-01-06
revision
2009-11-16
creation
2011-02-16
creation
2011-07-06
creation
2006-08-31
creation
2017-10-12
-5.8556
-5.7993
59.1404
59.1112
creation
2009-06-18
Scottish Continental Shelf
creation
2009-05-01
47E4
2009-06-26
2009-08-13
publication
2010-12-31
notPlanned
The North Rona BSM survey was divided into two phases; an acoustic survey and a ground-truthing survey. The objectives of the acoustic survey were to acquire bathymetric data using a dual frequency single beam echo sounder and high frequency sidescan sonar. The objectives of the ground-truthing survey were to acquire high resolution video and still photographs using a drop-down camera system and an ROV. Acoustic survey work was undertaken between 26th June and 2nd July 2009, onboard Seastar Survey Ltd's survey vessel RV Otarie. Ground-truthing survey work was undertaken later in the summer between 3rd and 13th August 2009 by the same contractors and survey vessel. 1) Acoustic survey work: acoustic field work was undertaken using a Leica 1200 RTK Rover GPS system, an EdgeTech FS 4200 dual frequency sidescan sonar system, and a Marimatech E-Sea Sound 206 dual frequency echosounder (33/200 kHz). The acoustic survey area was divided into three main areas (E, S, W) with 16, 20, and 13 planned acoustic lines in each, respectively, to simplify survey operations and ensure that the acoustic work was completed in its entirety within the SAC. Seabed backscatter data was collected using an EdgeTech 4200-FS dual frequency (120/410 kHz) sidescan sonar. Processing of the bathymetric data was undertaken using the post processing tools within the survey management software. This was undertaken with reference to the echo sounder paper trace records as part of our quality control procedures. 2) Ground-truthing survey work: fieldwork was undertaken using a Kongsberg OE 14-208 shallow water camera system mounted obliquely on a seabed camera frame. A flash unit and two sub-sea lights were also mounted on the frame. These units were linked to the surface with a soft umbilical cable. The shallow-water camera system was used for the ground-truthing of the sidescan sonar imagery. All camera deployments were established as transects across sites of interest, which were selected after scrutinising the acoustic survey data. The vessel was positioned at one end of a transect using DGPS. The camera was then deployed and lowered to the seabed. Once the camera system was at the seabed and had time to settle, the vessel drifted along the transect at approximately 0.5 knots. The camera frame was towed immediately above the seabed during the deployments, resulting in a seabed coverage of each still photograph of approximately 1 m2. Before each deployment a ‘clapper board’ containing site name, date and weather conditions was videoed and photographed as a quality assurance (QA) record.
publication
2018-01-23
true
See the referenced specification
Not for navigational use; This survey recorded no species or biotope occurrences that SNH consider as sensitive; all records may therefore be released in response to requests covered by Environmental Information Regulations or Freedom of Information Regulations; additionally its re-use and dissemination is permissible under Open Government Licence terms. Any re-use of this data will acknowledge the copyright owner.
no restrictions to public access
SeaStar Survey
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
2020-03-05