Identification

Title

1968 - 1968 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Southern North Sea Plankton Survey - RV Corella 06/68

Abstract

One of a series of 9 surveys in 1968 carried out to investigate plaice larvae in the North Sea. This data consists of the numbers of fish eggs and larvae and other zooplankton, along with associated positional data and volumes filtered, from the main net samples.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/2581/

function: order

Unique resource identifier

code

CEFAS9b4c9aff-110f-430d-88bc-cb5bc4a75ef1

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

-4.5

East bounding longitude

9

North bounding latitude

59

South bounding latitude

50.75

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

1968-04-05

End position

1968-04-15

Dataset reference date

date type

publication

effective date

2016-07-14

Frequency of update

notPlanned

Quality and validity

Lineage

Gear used was a 30" tin townet and a net changing device. As this is a historic dataset details of the exact configuration of gear used is not readily available. Details may be recorded in scientists red logbooks commonly used for surveys of this type. These are in storage at Cefas. Auxillary fine mesh ' pup' samples were also collected and analysed - this data is not available electronically - please contact data steward for further information. Sampler deployment: The sampler was deployed in a double oblique tow from the surface to within 2 m of the seabed. Veering and hauling speeds were manually adjusted to ensure that each depth band was sampled equally. At shallow stations, multiple double oblique dives were necessary to enable a sufficient volume of water to be filtered. A minimum sampler deployment time of 15 minutes was aimed for. On recovery, the net was carefully washed down and the sample collected from the end bag. Each sample was then fixed using buffered formaldehyde solution and transported to the laboratory for sorting and identification. Sample analysis: Fish eggs and larvae were picked out from all samples by eye and, whenever practicable, the whole sample was sorted. However sub-sampling was at times necessary. Fish larvae were readily identified unless they had been badly damaged during collection or were prematurely hatched. For some groups such as the sandeels (Ammodytidae) and the group of Gadidae commonly called rocklings, individuals were not identified to the species level. Fish eggs were initially split into three groups on the basis of the presence or absence of oil globules. Those containing either a single or many oil globules could usually be identified to the species level. Eggs with no oil globules were more difficult to identify. Some of these species such as cod (Gadus morhua), sprat (Sprattus sprattus), long rough dab (Hippoglossoides platessoides), dragonet (Callionymus spp.) and plaice (Pleuronectes platessa) were identified because of their size or unique features. Unidentified eggs in this group were recorded as egg diameters. Data storage: The raw data were stored on an Access database. The various data files were stored on the database in a series of tables linked by having the content of certain fields in common. All routine calculations, calibration changes and conversions were carried out on the database. The data tables (but not queries) have now been extracted into text files. Plankton data are normally expressed as either number of organisms per m3 or per m2. The number per m3 is obtained by dividing the numbers per sample by the volume filtered, calculated from the sampler flowmeters. Number per m2 is obtained by multiplying the number per m3 by the mean sampled depth during a deployment.

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

2016-07-14T12:28:23

Metadata language