2015 - 2018 Marine Biological Association of the United Kingdom (MBA) Western English Channel standard haul demersal fish survey data

Time series data of demersal fish populations in the Western English Channel sampled using a large otter trawl (15m headline) by the Marine Biological Association of the United Kingdom from 2015-2018. This data set contains vertebrate data only from 108 trawls. For each trawl, the entire catch was identified to species level. This dataset contains abundance, length, weight and disk width (if applicable) measurements. This dataset contains consistent sex data for elasmobranchs. Data of lower confidence levels has been excluded including that of invertebrates and sex data of non-elasmobranchs which can be requested via MBASepia@mba.ac.uk. These excluded data include high confidence cephalopod, scallop and large crab abundance as well as counts of other invertebrates including other crustaceans and echinoderms. Record Types (see SpeciesNotes in taxon form) describe the measurements that were carried out for the sample and/or individuals: Individuals - (Each individual caught has been weighed, measured and counted), Abundance / Weight - (All individuals landed have been weighed and counted as a whole, not individually), Sub-sample (Abundance) - (Measured total weight off all landed individuals, and from this estimated total abundance) & Sub-sample (Weight) - (Counted the total abundance of all landed individuals and from this estimated the total weight). The Sepia team database containing the MBA fisheries data automatically generates unknown weights to read as 1g, this means that it is near impossible to determine whether a weight is unknown or a genuine weight when reads as 1. Therefore any total biomass weights of 1g have been changed to 'unknown'. Individual specimen data has been retained as original vaues since these are more likely to have weights of 1g but should be treated as correct under the data user's discretion.