CEFAS248c7e00-d37b-4ddd-b574-dacec9ced31b English dataset Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk pointOfContact 2023-10-31T10:32:36 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Irish Sea Plankton Survey - RV Cirolana 04/88 2013-11-28 publication 2023-10-31 revision 2013-06-27 creation CEFAS2537 https://data.cefas.co.uk Surveys to target spring ichthyoplankton in the Irish Sea were carried out in 1987, 1988 and 1989 (and linked to an earlier series of *Nephrops norvegicus* L. larval surveys between March and June of 1982 and 1985). 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 (and also *Nephrops* larvae) identified from the main net samples collected on the survey in April/May 1988, along with associated positional and ancillary data and volumes filtered. Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk originator Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk custodian Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk distributor Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) data.manager@cefas.co.uk owner notPlanned Microzooplankton Phytoplankton Zooplankton SeaDataNet P03 parameter discovery vocabulary 2011-03-25 revision Plankton Advice Analysis Management Monitoring GEMET, version 1.0 2008-06-01 publication Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Water column SeaVoX Vertical Co-ordinate Coverages 2010-05-18 revision Marine Environmental Data and Information Network MEDIN metadata record availability 2012-01-11 publication data.gov.uk MEDIN metadata record availability 2012-01-11 publication otherRestrictions noLimitations otherRestrictions Public data - no limitations to reuse 1000 English biota -7.00 -3.00 53.00 54.75 1988-04-11 1988-05-04 Delimited Geographic Information System Unknown https://data.cefas.co.uk/view/2537 Cefas Data Portal download The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. Data is available in the following formats: CSV, ESRI Shapefile. The data can also be accessed via the WFS and WMS protocols. dataset INSPIRE Data Specification on Species Distribution – Technical Guidelines 2013-12-10 publication false See the referenced specification Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication true See the referenced specification Sampling: Plankton samples were taken with a modified version of the Lowestoft 76 cm diameter high-speed sampler. This was modified by increasing the overall length from 2.13 m to 2.75 m and by fitting a conical nose cone with an aperture of 40 cm diameter instead of a hemispherical one. The sampler was fitted with a 270 µm aperture mesh resulting in an open area to nose cone aperture ratio of 12:1. The sampler was deployed at a nominal speed of 2.5 m s -¹ 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. On recovery, the net was carefully washed down and the sample collected from the end bag. Each sample was then fixed in a 4% (w/v) formaldehyde solution and returned to the laboratory for analysis. The sampler, towed on a multi-cored electric cable, was fitted with both internal and external electronic flowmeters. Output was logged directly using a deck unit and used to calculate the volume of water filtered on each deployment. The flowmeters were calibrated in situ on the sampler using a circulating water channel. Under normal operating conditions, the sampler body accepts over ninety per cent of the theoretical volume of water offered to it at 2.5 m s-¹. Even under severe clogging, fifty per cent of this volume would still be filtered. The plankton sampler was fitted with a Guildline CTD sensor package and recording system which was used to continuously monitor temperature and salinity throughout the deployment. CTD systems were routinely calibrated at the beginning and end of each survey. The levels of precision (as the standard deviation about the mean based on the manufacturer's calibrations) were ± 0.04 psu for salinity and**±**0.02 ̊C for temperature. Plankton sample sorting and sub-sampling: Initially the 1982 and 1985 samples were sorted only for the larvae of *Nephrops norvegicus*. The samples were subsequently analysed for fish eggs and larvae, with the exception of the third survey in 1985 from 19-26 May, which had an incomplete coverage of the area. The samples taken in 1987,1988 and 1989 were sorted for all species. 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. Aliquots were removed using a 20 or 30 ml measured scoop. 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 unique size or special features. Unidentified eggs in this group were recorded as egg diameters. Data analysis and data storage (original):The raw data were stored in a customised database, initially using INGRES version 5, then transferred at a later date to Access version 2. 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 has now been extracted into comma separated variable 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. MEDIN 3.1.1