Publication Abstract

Discarding around the UK - New information and analyses: 1) English Channel, Western Approaches, Celtic & Irish Sea (ICES subarea VII)

R. Enever, A. Revill and A. Grant.

The Cefas catch and discard data collection programme has been conducting sampling operations on English and Welsh registered fishing vessels in ICES subarea VII since 2002. Within this subarea, these vessels were found to mainly fish in the English Channel, Western approaches, Celtic and Irish Sea. This paper presents the findings of this work and estimates the annual quantities of discards (fish and cephalopods) in terms of number and weight. The analysis was conducted on 3 643 hauls from 306 trips (142 different vessels) aboard commercial fishing vessels. An estimated 186 million (72 000 t) fish and cephalopods were caught every year of which 117 million (24 500 t) were discarded. Beam trawlers and otter trawlers were together responsible for more than 90% of these discards. Trawlers targeting Nephrops discarded the greatest proportion (by number) of fish caught (92%) followed by beam trawlers (71%) and otter trawlers (65%). In all, 182 fish and cephalopod species were caught, yet just 10 species, Pleuronectes platessa (European plaice), Limanda limanda (dab), Scyliorhinus canicula (lesser spotted dogfish), Trisopterus minutes (poor cod) Merlangius merlangus (whiting) and Triglidae (gurnards [5 species]) constituted more than 50% (61.5 million) of the annual discards. Length-frequency distributions (LFD) compiled from 706 015 length measurements illustrated that both discarded and retained fish from all gear groups were across a broad length range. We estimate that discarding levels in the region are much higher (x 4) than recently reported by the FAO.

Catch per unit effort (CPUE) data are used to describe spatial, temporal and gear-related patterns of discarding. A two-step cluster analysis (TSC) of the discard data revealed that most (97%) of the haul’s species composition and corresponding CPUE were similar in pattern. The remaining (3%) indicated discarding "hotspots", most notably in the Irish Sea and Western English Channel.

Reference

R. Enever, A. Revill and A. Grant (2007) Discarding in the English Channel, Western Approaches, Celtic and Irish seas (ICES subarea VII). Fisheries Research, 86: 143-152