26dee2f510202899e51ae2e5c876a51c English dataset Cornwall Inshore Fisheries and Conservation Authority Data Officer Cornwall IFCA Research Team enquiries@cornwall-ifca.gov.uk pointOfContact 2024-02-28 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::4326 2014 - Present, Cornwall Inshore Fisheries and Conservation Authority (IFCA) Fal Oyster Survey 2021-05-12 publication CIFCA_FAL_OYS_2014-Present Cornwall Inshore Fisheries and Conservation Authority (IFCA) conduct annual dredge surveys within the Fal Oyster Fishery since taking over management of the fishery in 2014. The purpose of the survey was initially to assess the distribution and abundance of native oysters (Ostrea edulis) within the Fal Fishery management area in the River Fal, Cornwall. Since 2016 the survey has been developed to also assess queenies (queen scallop, Aequipecten opercularis; variegated scallop, Mimachlamys varia) distribution and abundance. Slipper limpets (Crepidula fornicata) were initially recorded at each site using a SACFOR style scheme which was amended in 2018 to a count for this species. The aims of the survey were to investigate the relative abundance and distribution of native oysters (O. edulis), scallops (queen scallop, A. opercularis; variegated scallop, M. varia) and slipper limpets (C. fornicata) within the Fal Oyster Fishery. The distribution of substrate types across the fishery and species of bycatch were also recorded at each site in 2019. Research Team Cornwall IFCA Cornwall Inshore Fisheries and Conservation Authority enquiries@cornwall-ifca.gov.uk originator Research Team Cornwall IFCA Cornwall Inshore Fisheries and Conservation Authority enquiries@cornwall-ifca.gov.uk custodian annually Geographic Information System Marine Environmental Data and Information Network NDGO0005 Species distribution GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Shellfish abundance and biomass in water bodies SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision Bivalve molluscs Bivalves 2015-04-07 creation Data is freely available for research or commercial use providing that the originators are acknowledged in any publications produced and permission must be sought if the data will be reproduced in full or part or if used in any analyses. otherRestrictions No restrictions to public access 250 English biota Charting Progress 2 Sea Areas 2009-06-18 creation Western Channel and Celtic Sea ICES Rectangles 2009-05-01 creation 29E4 International Hydrographic Bureau, Limits of Oceans and Seas 1954-01-01 creation English Channel ICES Statistical Areas 2014-05-16 creation VIIe SeaDataNet vertical extent keywords 2010-01-01 revision water column -5.0653 -5.0063 50.1554 50.2482 2014-03-19 2024-02-28 0.8000 10.0000 All reports are available on request Research Team Cornwall IFCA Cornwall Inshore Fisheries and Conservation Authority enquiries@cornwall-ifca.gov.uk distributor dataset MEDIN data guideline for fish and benthos data by trawl or dredge 2018-10-08 publication See the referenced specification true In 2014 Cornwall Inshore Fisheries and Conservation Authority (IFCA) took over the management of the Fal oyster fishery, following the expiry of the Truro Port Fishery Order 1936 (as amended), and assumed responsibility for the continuation of oyster surveys and monitoring the stock of native oysters (Ostrea edulis) within the fishery, previously conducted by CEFAS/Cornwall Council. For data continuity the 95 sample sites used previously by CEFAS/ Cornwall Council were largely adopted for this survey, the exceptions being sites located on sensitive habitats (including seagrass and maerl beds) which could be damaged by the survey. A 72cm blade, Essex-style oyster dredge is used, rigged with 34mm diameter steel belly rings and a 45 mm (twin 3 mm nylon twine) mesh back. At each survey site the survey vessel is anchored and 60m of anchor line let out, the dredge is shot by hand and the hydraulic winch used to take up 50m of anchor line, resulting in a 50m dredge tow at a steady 0.5 to 1 knots. Each sample is photographed on the cultch board alongside the clapper board prior to sorting. Live oysters and scallops (queen/ variegated scallop) are counted and measured across the widest point (oysters) and along the length of the valve (from the hinge to the outer edge) (Scallops), to the nearest millimetre. Observations of substrate and by-catch are recorded alongside the oyster and scallop data for each dredge sample. An abundance scale is used to categorise substrate content, including slipper limpet (Crepidula fornicata) shell abundance. This should not be considered a definitive record of by-catch present at each site as it is not the primary reason for the survey. The size frequency distribution was graphed in Microsoft Excel and density maps were created in MapInfo Pro Advanced Version 17.0. Analysis was carried out comparing data from the geographic areas; outer harbour, harbour and river and management areas; A, B and C to ensure compatibility of the data with the oyster permit returns. For a full methodology please refer to the survey reports for each year.