{
    "@context": "https://schema.org",
    "@type": "Dataset",
    "@id": "http://portal.medin.org.uk/portal/json-ld/NRW_DS110926.jsonld",
    "identifier": "NRW_DS110926",
    "url": "http://portal.medin.org.uk/portal/?details&tpc=NRW_DS110926",
    "name": "Monitoring of Carbonate Reef Extent and Fish Population at Holden's Reef (2003 - 2010)",
    "description": "Holden's Reef is a small (approximately 40 m diameter), roughly circular reef situated in the northern sector of Cardigan Bay. It is unusual in being formed as a result of a chemical reaction between seawater and the escape of natural gas from the seabed, a phenomenon generally found in much deeper waters. Holden's Reef is one of an assemblage of methanogen-precipitated calcium carbonate reefs and was the first of the group to be discovered. This dataset contains the results of a programme of monitoring established to study fish populations and reef extent. It also includes data from an in-house survey carried out at Holden's Reef in 2003, initiated following the reef's discovery, and Marine Nature Conservation Review (MNCR) phase 2 surveys carried out in 2005 of \\Little\\\" and \\\"Big\\\" Reef. Holden's Reef is monitored for fish abundance and diversity extent and rugosity (the link between rugosity and fish abundance has been seen in several studies). This will contribute to condition assessment of the reef feature in the Pen Llyn a'r Sarnau Special Area of Conservation (SAC). Holden's Reef is situated more than 10 km off shore north west of Barmouth and is approximately 40 m in diameter. \"",
    "includedInDataCatalog": {
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    },
    "conditionsOfAccess": [
        "access: There are no access restrictions to this data. NRW may release, publish or disseminate it freely.",
        "access: no limitations",
        "use: \u00a9 CNC/NRW 2010. There are no use restrictions on this data. Recipients may re-use, reproduce, disseminate this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and NRW's copyright, and do not use it in a misleading context. It is the recipient's responsibility to ensure the data is fit for the intended purpose, that dissemination or publishing does not result in duplication, and that it is fairly interpreted. Advice on interpretation should be sought where required. To avoid re-using old data, users should periodically obtain the latest version from the original source."
    ],
    "temporalCoverage": "2004-05-18/2010-12-31",
    "keywords": [
        {
            "@type": "DefinedTerm",
            "identifier": "http://inspire.ec.europa.eu/theme/hb",
            "name": "Habitats and biotopes"
        },
        {
            "@type": "DefinedTerm",
            "identifier": "http://inspire.ec.europa.eu/theme/sd",
            "name": "Species distribution"
        },
        {
            "@type": "DefinedTerm",
            "name": "carbonate reef"
        },
        {
            "@type": "DefinedTerm",
            "name": "methane"
        },
        {
            "@type": "DefinedTerm",
            "name": "Holden's Reef"
        },
        {
            "@type": "DefinedTerm",
            "name": "Special Area of Conservation Monitoring"
        },
        {
            "@type": "DefinedTerm",
            "name": "fish ecology"
        },
        {
            "@type": "DefinedTerm",
            "name": "marine monitoring (see also marine surveys)"
        },
        {
            "@type": "DefinedTerm",
            "name": "Pen Llyn a'r Sarnau cSAC"
        },
        {
            "@type": "DefinedTerm",
            "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/FATX/",
            "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P02/current/",
            "termCode": "FATX",
            "name": "Fish abundance in water bodies"
        },
        {
            "@type": "DefinedTerm",
            "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/HBCH/",
            "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P02/current/",
            "termCode": "HBCH",
            "name": "Habitat characterisation"
        },
        {
            "@type": "DefinedTerm",
            "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/HBEX/",
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            "termCode": "HBEX",
            "name": "Habitat extent"
        },
        {
            "@type": "DefinedTerm",
            "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/FCNT/",
            "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P02/current/",
            "termCode": "FCNT",
            "name": "Fish taxonomy-related counts"
        }
    ],
    "spatialCoverage": {
        "@type": "Place",
        "geo": {
            "@type": "GeoShape",
            "box": "52.735966 -4.140899 52.741304 -4.129506"
        },
        "name": [
            {
                "@type": "DefinedTerm",
                "identifier": "http://vocab.nerc.ac.uk/collection/C19/current/1_4/",
                "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/C19/current/",
                "termCode": "1_4",
                "name": "Irish Sea"
            },
            {
                "@type": "DefinedTerm",
                "identifier": "http://vocab.nerc.ac.uk/collection/C19/current/UKMDN027/",
                "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/C19/current/",
                "termCode": "UKMDN027",
                "name": "Cardigan Bay"
            },
            {
                "@type": "DefinedTerm",
                "identifier": "http://vocab.nerc.ac.uk/collection/C19/current/UKMDN028/",
                "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/C19/current/",
                "termCode": "UKMDN028",
                "name": "Tremadog Bay"
            }
        ],
        "additionalProperty": [
            {
                "@type": "PropertyValue",
                "propertyID": "http://www.opengis.net/def/crs/OGC/1.3/CRS84",
                "value": "urn:ogc:def:crs:EPSG:4326"
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        "description": "The MEDIN portal contains information about 19493 marine datasets from over 600 UK organisations. Metadata are an enduring resource and contact details are publicly available for a long time. \r\n\t\tPlease contact us (enquiries@medin.org.uk) if you find your contact details on the MEDIN portal and do not consent to this. \r\n\t\tYou can now use our GitHub repository to report issues or access related documents. Metadata records are updated daily and were last updated 2026-04-19. Record deletion takes place weekly and the latest occurred 2026-04-12."
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