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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). In 1987 sampling was confined to the western Irish Sea. 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 (also *Nephrops* larvae) identified from the main net samples collected on the survey in May 1987, along with associated positional and ancillary data and volumes filtered.
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
| Other details | ||
| Internal code | Internally assigned metadata identifier | 11113 |
| Title | The title is used to provide a brief and precise description of the dataset such as 'Date', 'Originating organisation/programme', 'Location' and 'Type of survey'. All acronyms and abbreviations should be reproduced in full. | Irish Sea Plankton Survey - RV Cirolana 05/87 |
| File Identifier | The File Identifier is a code, preferably a GUID, that is globally unique and remains with the same metadata record even if the record is edited or transferred between portals or tools. | CEFASf44974dd-4efd-41c0-9a2e-e51e097c954b |
| Resource Identifier | This is the code assigned by the data owner. | CEFAS2541 |
| Resource type | The resource type will likely be a dataset but could also be a series (collection of datasets with a common specification) or a service. | dataset |
| Start date | This describes the date the resource starts. This may only be the year if month and day are not known | 1987-05-14 |
| End date | This describes the date the resource ends. This may only be the year if month and day are not known | 1987-05-24 |
| Spatial resolution | This describes the spatial resolution of the dataset or the spatial limitations of the service. | 1000 |
| Spatial resolution unit | This describes the unit of spatial resolution which for distance must be metres. | urn:ogc:def:uom:EPSG::9001 |
| Frequency of updates | This describes the frequency with which the resource is modified or updated i.e. a monitoring programme that samples once per year has a frequency that is described as 'annually'. | notPlanned |
| Abstract | The abstract provides a clear and brief statement of the content of the resource. | 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). In 1987 sampling was confined to the western Irish Sea. 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 (also *Nephrops* larvae) identified from the main net samples collected on the survey in May 1987, along with associated positional and ancillary data and volumes filtered. |
| Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | 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 in 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. |
| Related keywords | ||
| Keyword | General subject area(s) associated with the resource, uses multiple controlled vocabularies | Microzooplankton |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Phytoplankton | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Zooplankton | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Plankton | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Advice | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Analysis | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Management | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Monitoring | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Species distribution | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Water column | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Marine Environmental Data and Information Network | |
| Geographical coverage | ||
| North | The northern-most limit of the data resource in decimal degrees | 55 |
| East | The eastern-most limit of the data resource in decimal degrees | -2.5 |
| South | The southern-most limit of the data resource in decimal degrees | 51.75 |
| West | The western-most limit of the data resource in decimal degrees | -7 |
| Responsible organisations | ||
| Role | The point of contact is person or organisation with responsibility for the creation and maintenance of the metadata for the resource. | pointOfContact |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| Role | The originator is the person or organisation who created, collected or produced the resource. | originator |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| Role | The custodian is the person or organisation that accepts responsibility for the resource and ensures appropriate care and maintenance. If a dataset has been lodged with a Data Archive Centre for maintenance then this organisation is be entered here. | custodian |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| Role | The distributor is the person or organisation that distributes the resource. | distributor |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| Role | The owner is the person or organisation that owns the resource. | owner |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Resource locators | ||
| Locator URL | Web address (URL) that links to the resource | https://data.cefas.co.uk/view/2541 |
| Locator name | Name of the web resource | Cefas Data Portal |
| Dataset constraints | ||
| 20.1 Limitations on Public Access - Access constraints | Any restrictions imposed on accessing the resource such as the need to agree to certain licence conditions. | otherRestrictions |
| 20.2 Limitations on Public Access - Other constraints | https://inspire.ec.europa.eu/metadata-codelist/LimitationsOnPublicAccess/ | |
| 21.1 Conditions for Access and Use - Use constraints | Any restrictions imposed on accessing the resource such as the need to agree to certain licence conditions. | otherRestrictions |
| 21.2 Conditions for Access and Use - Other constraints | http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/gmxCodelists.xml#MD_RestrictionCode | |
| Version info | ||
| Date of publication | The publication date of the resource or if previously unpublished the date that the resource was made publicly available via the MEDIN network. | 2013-11-28 |
| Date of last revision | The most recent date that the resource was revised. | 2023-10-31 |
| Date of creation | The date that the resource was created. | 2013-06-27 |
| Metadata date | The date when the content of this metadata record was last updated. | 2023-10-31 |
| Metadata standard name | The name of the metadata standard used to create this metadata | MEDIN |
| Metadata standard version | The version of the MEDIN Discovery Metadata Standard used to create the metadata record | 3.1.1 |
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