CEFAS9f16c10a-feee-4a5b-801e-5d8a6d2ccfed 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 2020-11-12T02:31:08 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Eel survey records from estuaries around England and associated physical and environmental factors 1981-2018 2020-04-09 publication 2020-11-12 revision 2020-03-30 creation CEFAS20473 https://data.cefas.co.uk Data explored included long-term catches of eels in transitional and costal waters of England from 1981 to 2018 from the National Fish Populations Database, provided by the EA, from which we filtered data on adult eels in transitional waters as a final file to use in future analyses. The final csv file contains information on data owner, location of the survey site, specific site and survey IDs, survey specific date and associated information, GPS coordinates, survey method, species names, presence/absence data, count data, water body category, estuary name, transitional water body name and RBD name. The file also contains all the physical factors that were extracted from the numerous shapefiles provided by the EA or third parties (e.g. EMODnet Seabed Habitats, ESRI, British Oceanographic Data Centre). For the list of physical factors included please see 'Read Me' file. 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 Department for Environment, Food and Rural Affairs (DEFRA) defra.helpline@defra.gov.uk owner notPlanned Fish abundance in water bodies SeaDataNet P02 parameter discovery vocabulary 2011-03-25 revision Estuary Coastal environment Analysis GEMET, version 1.0 2008-06-01 publication Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Inapplicable 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 English biota -6.00 2.00 50.00 54.50 1981-01-01 2018-12-31 Binary Delimited Geographic Information System Unknown https://data.cefas.co.uk/view/20473 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: Binary download, 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 This desk-based project has explored available data on eel distribution/abundance in transitional waters of England and associated physical and environmental factors describing those waters at different spatial scales (River Basin District-RBD, estuary and site) to support national eel stock assessment. All data derived for this project came from third parties and are collated under this project for the purposes of future analyses of eel occurrences and/or abundances across different transitional water bodies to advise future data collection programmes and national stock assessment. The eel data in transitional waters were sourced from the National Fish Populations Database (NFPD), which compiles fisheries monitoring surveys performed in England by the EA and third parties. Only data from England transitional waters have been collated and explored to date, however a request was submitted to Natural Resources Wales (NRW) for fish data and adjacent environmental measures from Welsh transitional waters, especially those shared with England (e.g. Severn) and should these become available, they will be integrated into the existing dataset during future analyses. In addition, a request was logged with the EA to obtain the most relevant environmental factors (i.e. water temperature and salinity) measured during WFD fish surveys. Some physical characteristics of each RBD, estuary and survey site were added to the eel survey data. The latitude of the survey site was added as well as the latitude of the centre of the estuary and RBD. The WFD TraC shapefile was used to separate between transitional and coastal data, as investigating coastal eel distribution and abundance was not in the scope of this study (being subjects of future project phases). This shapefile was also used to calculate the extent of each RBD and estuary and to determine which coast each site is exposed to. The WFD river basin shapefile was used in conjunction with the barriers shapefile from the Environment Agency’s Barrier Database to calculate the number of obstructions to eel movement present within each RBD. The ratio between fresh and transitional waters per RBD was calculated using habitat specific wetted areas for the UK from the ICES 2019 WGEEL report. Seabed habitat and substrate data were collected from the EMODnet Seabed Habitats and the bathymetry map was provided by the British Oceanographic Data Centre. Other geographical information such as Euclidean distance to the nearest coast and distance from the Sargasso Sea were also calculated for each survey site. For determining the distance from each survey site to the coast, a shapefile from ESRI countries shapefile was used to define the coastline. The distance to the Sargasso sea was measured to a point in the centre of the Sargasso Sea, the exact extent of which is not clear, but for the purpose of this study a point located at 34°18'25.7"N, 66°16'10.3"W. The classification of drying extent was derived from calculating the percentage of each estuary that is exposed at mean low tide. This was done by using the intertidal shapefile provided by the Environment Agency upon request and the WFD transitional water bodies shapefile (Environment Agency, 2020a) to determine the extent of the intertidal zone. As none of the estuaries in the survey sites become completely desiccated, drying extent was classified into four categories depending on the percentage of the estuary that became exposed (<25, 25–50, 50–75 and >75). Sites and estuaries were classified as either sheltered, semi-exposed or exposed based on the level of exposure to the open sea. Level of exposure was calculated in ArcGis Pro 2.5.0, using a 1.5 km diameter circle and moving it towards the inlet of an estuary until contact was made with the coast at two points. A line was drawn between these two points and waters inside this line were classified as sheltered. A larger, 15 km diameter, circle was used to classify semi-exposed and exposed transitional waters, and this circle was moved towards the coast until the contact was made at two points and a second line was drawn between those two points. Water between the two lines was classified as semi-exposed and the water outside the second line was defined as exposed. The width of the mouth of each estuary was also measured as an indication of accessibility for the European eel and was also used to indicate exposure at estuarine level. Transitional water characterisation already exists for the UK under the WFD and is based on mixing, salinity, tidal range, exposure, depth and substratum type. As this is also a basis for designing fish surveys across different estuaries, WFD classification of transitional water bodies was requested from the Environment Agency and this was added to each survey site as a transitional waterbody type for use in future analyses. MEDIN 3.1.1