53e1c770f5b08f9838536e17b049dbb3 English dataset 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 pointOfContact 2019-08-09 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::27700 1998 Centre for Environment, Fisheries and Aquaculture Science (CEFAS) Cross Sands broadscale macrobenthic survey (impacts of aggregate extraction). 2006-12-31 publication 1998-01-01 creation 2006-12-31 revision MRMLN00400000081 http://dassh.ac.uk Benthic marine species abundance data from an assessment of the cumulative impacts of aggregate extraction on seabed macro-invertebrate communities The purpose of this study was to determine whether there was any evidence of a large-scale cumulative impact on benthic macro-invertebrate communities as a result of the multiple sites of aggregate extraction located off Great Yarmouth in the southern North Sea. Contracts office CEFAS Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory Officer +44 (0)1502 562244 +44 (0)1502 513865 Pakefield Road Lowestoft NR33 OHT contracts@cefas.ac.uk originator 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 custodian asNeeded Database Delimited Marine Environmental Data and Information Network Geology Habitats and biotopes Land use Species distribution GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Zoobenthos generic abundance Fauna abundance per unit area of the bed Shellfish abundance and biomass in water bodies Habitat extent Habitat characterisation Industrial activity Sediment grain size parameters SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision Released under DASSH terms and conditions otherRestrictions Released under DASSH terms and conditions https://www.dassh.ac.uk/terms-and-conditions English geoscientificInformation biota planningCadastre biota Charting Progress 2 Sea Areas 2009-06-18 creation Southern North Sea 1.7000 2.5300 52.1800 52.8500 1998-01-01 1998-12-31 Cooper, Boyd (2006) Cross sands broadscale survey 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 An assessment of the cumulative impacts of aggregate extraction on seabed macro-invertebrate communities. The purpose of this study was to determine whether there was any evidence of a large-scale cumulative impact on benthic macro-invertebrate communities as a result of the multiple sites of aggregate extraction located off Great Yarmouth in the southern North Sea. Forty 0.1m2 Hamon grab samples were collected from across the region, both within and beyond the extraction area, and analysed for macrofauna and sediment particle size distribution in order to produce a regional description of the status of the seabed environment. In addition, the data were analysed in relation to the area of seabed impacted by dredging over the period 1993-1998. Areas subject to 'direct' impacts were determined through reference to annual electronic records of dredging activity and this information was then used to model the likely extent of areas potentially subject to 'indirect' ecological and geophysical impact. Results showed the study area to be characterised by sands in the northern half of the survey area, and sandy gravels in the south. The low diversity communities found across much of the survey area were typical of mobile sandy sediments. However, stations located in the southern half and northern extreme of the survey area tended to support higher numbers of species and individuals. This may be due to marginally enhanced stability arising from the higher proportion of gravel found in samples to the south of the extraction licenses and to the presence of Sabellaria spinulosa reef in the north. Analysis of data in relation to areas of predicted dredging impact revealed proportionally less gravel and more sand within the 'direct' impact zone, compared to the 'indirect' impact zone. Whilst multivariate analyses of macrofaunal data did not clearly discriminate between dredging impact zones, a comparison of univariate measures revealed significantly lower numbers of species and individuals in areas which have been subject to 'direct' dredging impacts in comparison with 'reference' areas. This provides good evidence of the near-field consequences of dredging. Values of these measures in the 'indirect' zone were intermediate, although not significantly different from the 'reference' zone. We conclude that, although the dominant influence on assemblages in the region is that of sediment instability induced by tidal currents, we cannot dismiss the possibility of a subsidiary influence of dredging activity in the near vicinity of the licensed block and further investigation is warranted. Methods: The work was carried out in 1998 using a 0.1m2 Hamon grab. Samples were seived over a 1mm mesh sieve.