1995 - 1995 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Irish Sea Annual Egg Production Method (AEPM) Plankton Survey 1995
Between February and May of 1995 a series of plankton surveys were carried out in the Irish Sea by the Centre for Environment, Fisheries and Aquaculture Science, and a number of partner research institutes, to undertake stock assessment by the egg production method. The species targetted were cod, sole and plaice. Ichthyoplankton samples were collected at each site on a planned survey grid. The data described here consists of the numbers of fish eggs and larvae identified from the main net samples collected, along with associated positional and ancillary data and volumes filtered. In addition, 69 main net samples were later analysed for mesozooplankton (12 to 16 samples from 5 of the cruises), and these data are also included.
dataset
http://data.cefas.co.uk/#/View/2633/
function: order
CEFAS8750fc58-911a-442c-840b-6e657b368b17
http://www.cefas.co.uk/
eng
OGP
urn:ogc:def:crs:EPSG::4326
biota
revision
2011-03-25
publication
2008-06-01
publication
2008-06-01
-7
-2.5
55
51.75
revision
2010-05-18
1995-01-01
1995-12-31
publication
2020-06-16
notPlanned
Gulf III type of plankton samplers were used on these surveys. Sampling on RV Cirolana/Corystes used 76 cm un-encased body, 40 cm diameter nosecone, 270 um mesh main net, Guildline CTD and Cefas logging software, auxillary un-encased PUP sampler, 5 cm diameter opening nosecone, 80 um mesh net, Valeport flowmeters with Cefas continuous logging. Sampling on RV Lough Foyle used 76 cm un-encased body, 40 cm diameter nosecone, 270 um mesh main net, auxillary un-encased PUP sampler, 5 cm diameter opening nosecone, 80 um mesh net, SeaBird CTD and Pro-net logging software, Valeport flowmeters with Pronet continuous logging. Sampling on RV Celtic Voyager used 76 cm un-encased body, 40 cm diameter nosecone, 270 um mesh main net, SeaBird CTD and Pro-net logging software, Valeport flowmeters with Pronet continuous logging. The sampler was deployed at a speed of 4.5 knots 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. 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. 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 in the database. The data tables (but not queries) have now been extracted into comma separated variable files. Plankton data are normally expressed as either number of organisms per m3 or per m2. These are calculated from the volume of water filtered (derived using regression co-efficients calculated for different flowmeters). Number per m3 is obtained by dividing the numbers per sample by the volume filtered, and number per m2 of sea surface is obtained by multiplying the number per m3 by the mean total or sampled depth during a deployment. **Survey Corystes 8/95 as given in the Station ID and Cruise fields should read Corystes 4/95**. Data remains unaffected - only cruise number is incorrect.
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
originator
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
custodian
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
pointOfContact
2020-06-16T11:49:18