CEFASa4055838-62f0-4992-aeb0-097c2112b0a0
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
1990 - 1990 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Bristol Channel, western English Channel, Celtic Sea Plankton Surveys - RV Corystes 05/1990
2019-10-29
publication
CEFASa4055838-62f0-4992-aeb0-097c2112b0a0
http://www.cefas.co.uk/
Analysis of plankton samples collected on a series of surveys in 1990 to
determine the extent and timing of sole (Solea solea) spawning. Numbers of
ichthyoplankton, Nephrops larvae and edible crab (Cancer pagurus), along with
associated positional and environmental data (temperature and salinity).
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
-12
-1
48
52.5
1990-04-01
1990-04-26
dataset
A series of surveys to estimate the spawning stock biomass of sole (*Solea
solea*) in the Bristol Channel area (see also separate records for surveys
Corystes 4 and 6/89), western English Channel and Celtic Sea. Identity where
possible of all species of fish eggs and larvae determined. Developmental
staging for eggs of sole and plaice and for edible crab larvae undertaken.
Data consists of the numbers of fish eggs and larvae, crab larvae, along with
associated positional data and volumes filtered, from the main net samples. It
does not include all LHPR sample analysis.
**Associated Datasets: **Temperature and salinity "V" profiles are available
at each sampling position. Continuous near-surface (3m) temperature and
salinity data are available for complete cruises.
Samples were collected using a 76cm High Speed Tow Net, a 53cm Tow Net fitted
with a Guildline Conductivity Temperature Depth (CTD) monitoring system and a
Longhurst-Hardy Plankton Recorder.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) 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.