Identification

Title

2006 - 2006 Centre for Environment, Fisheries & Aquaculture Science (Cefas) North Sea whiting 2006/07 - Fisheries Science Partnership

Alternative title(s)

FSP North Sea whiting

Abstract

To investigate stomach contents of North Sea whiting to determine their diet, and any possible changes to that diet since the last large-scale stomach survey in 1991. The project will specifically address the potential problem of predation of whiting on cod, which, if frequent, may affect cod recovery.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/626/

function: order

Unique resource identifier

code

CEFASf397b9fc-933a-418a-999a-72a93c2d3990

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

Geographic location

West bounding longitude

-3.5

East bounding longitude

2.5

North bounding latitude

56.75

South bounding latitude

53

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

2006-08-01T00:00:00.000Z

End position

2006-10-31T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2017-02-14

Frequency of update

notPlanned

Quality and validity

Lineage

FV Nimrod BH-227 is a wooden trawler of overall length 16.5m. The vessel deployed an otter trawl similar to a Whitby jet trawl. This was used to fish over both soft and hard substrata as required in the survey. Two nets were used during the survey, one with an 80mm codend and the other fitted with a 40mm shrimp mesh liner. Both nets were fitted with 40’ (12.2m) of 14” (355mm) hoppers and were spread by a set of No.8 Bison trawl doors. The nets had a headline height of 14’ - 18’ (4.3 – 5.5m). The bridle length was 25 fathom (45.7m) splits and 10 fathom (18.3m) single. Fishing for the August survey was undertaken within British Fishery Limits in the North Sea between longitudes 2o W and 2° E, and bounded in the north by approx. 56.5° N and in the south by 53.5° N in ICES rectangles 36F0, 37E9, 37F0, 37F1,38E9, 38F0, 38F1, 39E8, 39E9, 39F0, 40E8, 40E9, 41E8 and 41E9. During the August survey, and in consultation with Cefas staff, an additional rectangle 38E8 was sampled once. This area was known to be a good fishing ground for whiting. For the October survey a change to the locations surveyed was made to include two hour-long hauls in ICES rectangle 38E8 and to exclude all hauls from 39F0. This change was based on whiting catches during the first survey, which were high in 38E8 and low in 39F0. Fishing was conducted in order to sample whiting representatively from the area of interest. 1. The sampling took the form of tows of 1h duration. Multiple short tows as opposed to fewer long tows are desirable for stomach content evaluation as the statistical power of the data analysis is improved. 2. Two 1h tows were undertaken within the ICES rectangle. 3. The start and end positions of the tow were decided by the skipper, as long as all other requirements detailed in section “Survey area” were met. Processing of catch and stomach sampling A length distribution was obtained by measuring a representative number of whiting from each haul. Normally this was the lengths of one basket of fish with a raising factor according to the number of baskets, but due to small catches in some hauls, all fish were measured. The catch of whiting was sorted into length categories 15 – 19cm, 20 – 24cm, 25 – 29cm, 30 – 34cm and 35+cm. Stomachs were opened and non-empty stomachs were placed into freezer bags and frozen for subsequent analysis in the laboratory. This continued until 10 fish from each size category were collected or until no fish remained in the appropriate size category. Any remaining whiting in the sub-samples were examined onboard and stomach contents were marked on a simple tick sheet. This allowed an initial idea of what was present in the stomachs of whiting as well as allowing a large number of samples to be processed.

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

2017-02-14T10:26:48

Metadata language