5152a22740e6c9dc93c870a8b1452e12 English dataset Carly Cassidy University Marine Biological Station (UMBS), Millport Millport KA28 0EG carlycassidy@hotmail.co.uk pointOfContact 2019-11-11 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::0 urn:ogc:def:crs:EPSG::4326 2000-2002 University Marine Biological Station Millport (UMBSM) Clyde Sea Technical Improvements Assessment Survey 2000-2002 University Marine Biological Station Millport (UMBSM) Study Contract Clyde Sea Technical Improvements Assessment Survey EC Study Contract 99/077 2002-12-01 publication DASSH-117 An investigation was carried out to study the behaviour of three fishing fleets, two in Scotland and one in Italy, by using GPS-linked position recording units (PRUs). Eighteen fishing vessels, representative of the Nephrops (Nephrops norvegicus) trawler fishing fleet in the Clyde Sea area and Sound of Jura, were fitted with PRUs. Seventeen vessels, in the Ancona District of the Central Adriatic, which fish for clams (Chamelea gallina) by hydraulic dredge, were also fitted with position recording units. Position recording units were used to identify the spatial pattern of fishing effort and landings. By using PRUs, it is possible to gain a better understanding of fishery stocks for analytical and fishery-independent assessments. The PRU methodology also provided information on the fisheries impact on the environment. An investigation into the fishing power in the Clyde and Adriatic fisheries was also undertaken. Philip Smith University Marine Biological Station (UMBS), Millport Millport KA28 0EG philip.smith@millport.gla.ac.uk originator Kathryn Stevenson University Marine Biological Station (UMBS), Millport Millport KA28 0EG kathryn.stevenson@millport.gla.ac.uk custodian notPlanned Delimited Documents Marine Environmental Data and Information Network Sea regions Species distribution GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Fish and shellfish catch statistics Fishery characterisation Fishing by-catch SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision The contents of this report may not be reproduced unless the source of the material is indicated. otherRestrictions Dassh terms and conditions apply (https://www.dassh.ac.uk/terms-and-conditions) English oceans biota Charting Progress 2 Sea Areas 2009-06-18 creation Irish Sea SeaDataNet vertical extent keywords 2010-01-01 revision benthic boundary layer SeaDataNet vertical extent keywords 2010-01-01 revision infralittoral SeaDataNet vertical extent keywords 2010-01-01 revision soil and sediment -5.9546 -4.6198 54.8671 55.9861 2000-10-01 2002-10-01 Data Archive for Seabed Species and Habitats (DASSH) Data Manager 01752 633102 01752 633291 Marine Biological Association of the UK, The Laboratory, Citadel Hill Plymouth PL1 2PB dassh.enquiries@mba.ac.uk distributor dataset MEDIN data guideline for video surveys of species and benthos. 2018-01-23 publication See the referenced specification true The project was carried out by members of the Marine Biological Station Millport (UMBSM), Fisheries Research Services, Marine Laboratory Aberdeen (MLA) and Istituto di Richerche sulla Pesca Marittima and with the financial assistance of the European Commission. The report does not necessarily reflect the views of the European Commission. The study project is in support of the Common Fisheries policy. The purpose of this study was to improve the assessment and management of important stock fisheries. Fitting commercial fishing vessels with PRUs enabled a sufficient level of data to be recorded from all three areas (Clyde Sea area, Ancona District and Fladen Ground (preliminary study)). The data collected was used to produce high resolution maps and establish the fishing effort and landings within the fisheries. The position recording unit comprised of a data-logger and a GPS satellite receiver. Positional data was collected by a Smart Antenna RS232 (CMC Electronics). The data logger was based around Triangle Digital Services TDS2020 16- bit control computer (www.TriangleData.com). Data was stored on an 8MB Compact Flash Memory card and downloaded via a PCMCIA slot in a notebook using a CF-PCA adapter or by using a serial link (with a terminal emulator programme). Data was stored in csv format. During the study, three Nephrops fisheries were investigated in Scotland (Clyde, Jura and Fladen). Comparisons could be made between sites. The Clyde Sea fishing grounds has a Nephrops stock of around 25,000 tonnes, with high exploitation rates. The Fladen Ground, off the north-east coast, holds a Nephrops stock of approximately 100,000 tonnes, however exploitation rates are low at only 6%. The Sound of Jura grounds are relatively small and account for landings of 174 tonnes. Density levels vary between sites within the Clyde Sea area as it is the most densely populated site per unit area, while the Fladen Ground holds the lowest density of Nephrops per unit area. In-house studies and published data provided information on the sediment type distribution within each study area. Nephrops population characteristics vary in correlation with the sediment category in which they burrow. Spatial factors are crucial in establishing precision stock assessments. Current stock assessment methods were developed for fin fish assessments. 60,000 tonnes of Nephrops are caught annually by the European Nephrops fishery. The Scottish Nephrops fishery accounts for one third of the European total. For Nephrops fishery management, it is important to recognise that population characteristics and heterogeneity varies in accordance to the substrate type within areas of the fishery ground. Stock assessment methods which do not account for such a variability could potentially produce erroneous results. The present study aimed to improve the assessment of stock. Population heterogeneity on varying sediment types was investigated and established by using data obtained from market and discard samples in correlation with a underwater television (UWTV) unit attached to a research vessel. RV Aora and RV Scotia deployed the UWTV unit (based on an aluminium sledge) and was towed at a speed of less than 1 knot. A Kongsberg-Simrad (OE 1362) colour camera was used by UMBSM during surveys. The camera was fitted with three underwater lights (1 x Kongsberg-Simrad (300W) and 2 x Versabeam Remote Ocean Systems (500W)). MLA used the OE 1364 series fitted with 4 Versabeam lights. The length of ground covered by UWTV trawls was measured using an odometer (confirmed by DGPS). Both cameras had a fixed focal length and viewed an area of sea bed of a known width. Trawl catch samples from the study grounds identified mean size variances of stock occupying different sediment types. Within the Ancona district, PRUs attached to dredgers fishing for clams recorded that the ground was over exploited. PRU's identified that every square meter of ground within the fisher had been dredged at least once during the year and that fleet behaviour varied seasonally. The environmental impact of the fishing fleet in the Ancona was assessed by investigating discards and bycatch.