Identification

Title

1997 - 2012 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Nephrops underwater TV Surveys in the Eastern Irish Sea (video data and database)

Alternative title(s)

Nephrops burrow counts

Abstract

Underwater TV (UWTV) surveys dataset, used as basis of the Nephrops ( *Nephrops* *norvegicus* ) assessment to develop fishery independent indicators of stock size, exploitation status and catch advice. The standard methodology involves the use of a sledge mounted camera to film the seabed at a fix grid of stations conducting TV tows for 10 minutes. Data has been collected in 1997, 1998, 2007 to 2012 and yearly from 2014. The dataset holds data from the East Irish Sea (FU14). Station data are held electronically. TV footage is held on VHS tapes and on DVDs and backup up electronically from 2014.

Resource type

dataset

Resource locator

Unique resource identifier

code

CEFAS0205ca85-3e50-44f3-8bcb-2c29239974cd

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

Additional information source

Related publications can be searched for at the following link: `http://www.ices.dk/publications/library/Pages/default.aspx`_ .. _`http://www.ices.dk/publications/library/pages/default.aspx`: http://www.ices.dk/publications/library/Pages/default.aspx

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

-4.5

East bounding longitude

-3

North bounding latitude

55

South bounding latitude

53.75

Extent

Extent group

authority code

title

reference date

date type

revision

effective date

2010-05-18

code identifying the 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

1997

End position

2012-08-08

Dataset reference date

date type

publication

effective date

2017-01-20

Frequency of update

annually

Quality and validity

Lineage

The full dataset consists of approximately 160+ VHS tapes (1996 to 2002) and 260+ DVD discs (2003 to present) plus additional back-up tapes. The DVD discs are kept for reference and quality-control purposes at Cefas, Lowestoft, for a period of 5 years, after which they may be disposed of. The VHS tapes are now obsolete but will be retained until January 2017 at which time they may be disposed of. Material can be made available upon request (please contact data steward for more information). Station data comprise positional information and Nephrops burrow counts and have been stored in a shellfish Access database since 1997. In line with SGNEPS (Study Group Nephrops) recommendations all scientists are trained/re-familiarised using training material and validated using reference footage (measured by Linn’s concordance correlation coefficient (CCC)) prior to recounting each survey footage. A limit of 0.5 is used to identify counters who need further training. On completion of this process, all survey recounts are conducted, as blind counts, by two persons during the survey. Here, the number of Nephrops burrow systems and the activity in and out of the burrows are counted by each minute block (for 7 clear minutes). In cases where the field of view became obscured by cloud, the number of seconds obscured are recorded and all minute blocks with more than 20 seconds obscured are rejected for analysis. After all counts completed again the Linn’s CCC is again applied to check which stations needed to be revisited and were a 3rd or 4th counter needed to be added. Whilst reviewing the videos, the visibility, ground type, trawl marks, occurrence of bio-fauna, ground contact of the sledge, cloud and any other interference is recorded during each one-minute intervals, using a classification key. Example footage and a training presentation is available via the metadata record entitled 'Nephrops underwater TV Surveys - VHS and DVD footage'. `http://data.cefas.co.uk/#/View/3020`_ .. _`http://data.cefas.co.uk/#/view/3020`: http://data.cefas.co.uk/#/View/3020

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

2017-01-20T15:35:10

Metadata language