Identification

Title

2015 - 2015 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Fladen experimental fishing impact recovery data - Seabed imagery analysis

Abstract

Total counts and derived abundance codes of individual taxa identified from video files & still photographs of the seabed and total counts of nephrops burrows identified from video files, with associated station information. The digital video and still photographs were acquired from cameras mounted on a camera sledge frame at sampling stations located within six experimental boxes (three treatments and three control) during a fishing impact recovery survey within the Fladen Grounds. Data were collected at three time points (before impact (time 0), immediately after impact (time 1) and 8 months after impact (time 2) during two research surveys on the RV Cefas Endeavour in April 2015 and November 2015.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/19337/

function: order

Unique resource identifier

code

CEFAScbde560c-ba55-4267-ad93-8ac8b89daaab

codeSpace

http://www.cefas.co.uk/

Dataset language

eng

Spatial reference system

authority code

OGP

code identifying the spatial reference system

urn:ogc:def:crs:EPSG::4326

Classification of spatial data and services

Topic category

biota

Keywords

Keyword set

keyword value

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

revision

effective date

2011-03-25

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

publication

effective date

2008-06-01

Geographic location

West bounding longitude

0

East bounding longitude

0.5

North bounding latitude

58.25

South bounding latitude

58

Extent

Extent group

authority code

title

reference date

date type

revision

effective date

2010-05-18

code identifying the extent

Temporal reference

Temporal extent

Begin position

2015-04-17T23:00:00.000Z

End position

2015-11-27T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2020-09-10

Frequency of update

notPlanned

Quality and validity

Lineage

Two camera sledge tows were positioned diagonally across each of the six experimental boxes. The camera sledge system comprised a Kongsberg 208 video camera with still image capability. Illumination was provided by four high intensity LED lights and a dedicated flash unit. The camera was orientated to provide a forward oblique view of the seabed and was fitted with a four-spot (red) laser-scaling device which projected the corners of a 17cm x 17cm square along the axis of the lens onto the seabed. Set-up and operation followed the MESH ‘Recommended Operating Guidelines (ROG) for underwater video and photographic imaging techniques. A video overlay was used to provide station metadata, time and position (of the GPS antenna) in the recorded video image. The camera sledge was towed at ~ 0.3 knots and still images were captured at one-minute intervals. The position of the sledge was derived from a High Precision Acoustic Positioning (HiPAP) beacon which was continuously logging at 10 second intervals throughout the tow. Video and still photographs were analysed to identify the broadscale habitats within the video record, to provide abundance and the Marine Nature Conservation Review (MNCR) Abundance Scales (SACFOR) data on the species present and to quantify the number of nephrops burrows present. Identification of taxa was limited to a level that could be confidently achieved from the available image. Quality was managed through a quality control system in place by the contracting laboratory undertaking the seabed imagery processing and by Cefas.

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Constraint set

Limitations on public access

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Responsible organisations

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

originator

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

custodian

Metadata on metadata

Metadata point of contact

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

pointOfContact

Metadata date

2020-09-10T13:23:57

Metadata language