CEFASabb5f64c-16a6-4b3a-9625-9ead31642ef1
English
dataset
Centre for Environment, Fisheries & Aquaculture Science
Data Manager
+44 (0)1502 562244
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
Suffolk
NR33 0HT
UK
data.manager@cefas.co.uk
pointOfContact
2016-08-22T15:25:30
MEDIN Discovery Metadata Standard
Version 2.3.7
urn:ogc:def:crs:EPSG::4326
OGP
1993 - 1997 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Blackwater Estuary Plankton Survey
2016-08-22
publication
CEFASabb5f64c-16a6-4b3a-9625-9ead31642ef1
http://www.cefas.co.uk/
A series of plankton surveys were undertaken on charter vessels Gill and
Oceanus in the Blackwater Estuary between 1993-1997 in order to examine
herring larval growth, dispersal and feeding. Samples of fish eggs and larvae,
juvenile fish and mesozooplankton were collected for analysis. Data also
includes associated positional and ancillary data (e.g. surface salinity and
temperature) and estimates of water volumes filtered.
Centre for Environment, Fisheries & Aquaculture Science
Data Manager
+44 (0)1502 562244
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
Suffolk
NR33 0HT
UK
data.manager@cefas.co.uk
originator
Centre for Environment, Fisheries & Aquaculture Science
Data Manager
+44 (0)1502 562244
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
Suffolk
NR33 0HT
UK
data.manager@cefas.co.uk
custodian
notPlanned
Delimited
NDGO0005
Microzooplankton
Zooplankton
Plankton abundance per unit volume of the water column
SeaDataNet P021 parameter discovery vocabulary
2011-03-25
revision
Plankton
Advice
Analysis
Management
GEMET, version 1.0
2008-06-01
publication
Species distribution
GEMET - INSPIRE themes, version 1.0
2008-06-01
publication
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
otherRestrictions
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
1000
English
biota
SeaVoX Vertical Co-ordinate Coverages
2010-05-18
revision
Water column
0
2
51.25
52
1993-01-01
1997-12-31
http://data.cefas.co.uk/#/View/2632/order
dataset
Sampling used Gulf VII with 20 cm main net opening, 270 um mesh net, also
carried pup sampler, 5 cm diameter nose cone opening and 80 um mesh net.
FSI-mCTD with accesory turbidity probe, Valeport flowmeters with internal
logging package.
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 participating
laboratories 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. Sub-sampling was carried out using a Folsom splitter. 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 etc.) 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.