CEFASdf783bfe-cca0-4aab-a524-afb55f834312
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
2019-10-29T10:09:44
MEDIN Discovery Metadata Standard
Version 2.3.7
urn:ogc:def:crs:EPSG::4326
OGP
1999 - 1999 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Irish Sea Plankton Survey - RV Corystes 02/99
2019-10-29
publication
CEFASdf783bfe-cca0-4aab-a524-afb55f834312
http://www.cefas.co.uk/
As part of the aims of this survey carried out from the 1st-25th March 1999 in
the Irish Sea plankton samples were collected in the plaice spawning areas in
the eastern Irish Sea. This data consists of the numbers of plaice eggs
identified in the Gulf VII main net samples, along with associated positional
and ancillary data and volumes filtered.
notPlanned
Delimited
NDGO0005
Microzooplankton
Phytoplankton
Zooplankton
SeaDataNet P021 parameter discovery vocabulary
2011-03-25
revision
Plankton
Advice
Analysis
Management
Monitoring
GEMET, 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
SeaVoX Vertical Co-ordinate Coverages
2010-05-18
revision
Water column
-4.5
-3.5
53.25
53.75
1999-03-01
1999-03-25
dataset
Samples were collected using an unencased 76 cm Gulf VII high speed towed net
with a 40cm diameter nosecone opening and 270µm mesh"
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. 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) 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.