Realm: Marine
Climate: Temperate
Biome: Temperate shelf and seas ecoregions
Central latitude: 53.928422
Central longitude: -0.500147
Duration: 5 years, from 1992 to 1996

1347 records

212 distinct species

Across the time series Paguridae is the most frequently occurring species

Methods

Day grabsDuring April and May 1993. and in February and May1994. samples of the benthic macrofauna were collectedfrom MAFF research vessels at each of 25 ??intermediate??and ??offshore?? stations around the Englandand Wales coastline. following the guidelines of theNMP (Anon.. 1994; see also Fig. 1). One station in theSW Approaches (S48) was sampled in December 1992.i.e. outside the recommended February to May samplingwindow. but this offshore. deep-water environment wasincluded as a clean-water ??reference?? point. (An attemptto sample S48 in February 1994 had to be abandoneddue to bad weather.) An additional station off the TeesEstuary was sampled to provide information on theshallow coastal environment in this area.At each location. five sediment samples for macrofaunaanalysis were collected using a 0.1 m2 day grabfrom the central point of a 500 m grid of 9 stations. thelatter being sampled for contaminant analyses only.The five replicates were collected from within a 100 mrange ring. using SEXTANT software and DGPSposition-fixing.The depth of sediment in the closed jaws of the grabwas determined. as an indication of sample volume.Very small samples (i.e. less than about 5 cm depth) werediscarded. A visual description of the sediment type wasrecorded. together with the location and times at whichthe sample was collected. and the prevailing sea state.wind strength. and water depth. A small subsample forsediment particle size analysis was removed using a 2 cmdiameter perspex corer inserted to a depth of about5 cm. The contents of the grab were transferred to ahopper. and gently washed over a 1 mm mesh brasssieve. The retained material was preserved for analysis in5% formaldehyde in seawater with added Rose Bengal.Beam trawlsSamples were obtained by MAFF research vessels from69 stations between 1992 and 1996 (Fig. 1).A standard 2 m Lowestoft beam trawl (Riley et al..1986) with a 3 mm mesh codend liner was deployedfor 5?10 min across each station at a speed of about0.5 m s1. The ??start?? (locking of winch followingseabed contact) and ??end?? (commencement of hauling)positions were recorded. Tow length averaged about400 m. but varied substantially (s.d.=290) depending ontidal current velocity and wind strength at the time ofsampling. On retrieval of the trawl. an estimate ofsample volume was made. along with a summary of thecontents. noting especially the presence of stones. rock.etc. The sample was then sorted on deck over a 5 mmmesh sieve. Most specimens were identified and enumeratedat sea. Any problematic specimens were preservedin formalin for identification on land.The presence of infaunal organisms arising from thefouling of soft sediments was noted. as were occurrencesof pelagic species such as jellyfish. However. theserecords were excluded from the final compilation of thedata. The former included most polychaete worms (withthe exception of encrusting forms such as Sabellaria andFilograna. and surface-dwelling specimens within thefamily Aphroditidae). bivalve molluscs (excepting taxawith a surface-dwelling habit such as Chlamys andModiolus). and burrowing echinoderms such asEchinocardium and Amphiura. In the following account.the faunal data are reported as numbers per tow. i.e.unadjusted for tow length.Laboratory analysisInfauna and sedimentsThe macrofauna was identified to species level. as far aspossible. with the use of a range of standard taxonomickeys. All animals were enumerated. with the exceptionof colonial organisms which were recorded on apresence/absence basis. Nomenclature followed that ofHowson (1987). The biomass of each taxon was determinedas wet blotted weight. and then expressed asash-free dry weight using conversion factors mainlyfrom Rumohr et al. (1987).EpifaunaMotile taxa not dealt with at sea were identified tospecies level. as far as possible. using a range of standardtaxonomic keys. Nomenclature followed that ofHowson (1987). Unit of abundance = IndCountInt, Unit of biomass = NA

Citation(s)

Rees, H., Pendle, M., Waldock, R., Limpenny, D. & Boyd, S. (1999) "A comparison of benthic biodiversity in the North Sea, English Channel and Celtic Seas - Epifauna". Centre for Environment, Fisheries and Aquaculture Science; Burnham Laboratory, UK. Available at: http://www.iobis.org/mapper/?dataset=51, accessed 2012.
Rees, H., Pendle, M., Waldock, R., Limpenny, D. & Boyd, S. (1999) A comparison of benthic biodiversity in the North Sea, English Channel, and Celtic Seas. ICES Journal of Marine Science, 56, 228-246.