Catch weights data from a bottom trawl survey series: Trawl positions, duration and gear parameters; catch weights of the target species; length frequency distributions; age, sex and maturity. The target species are: cod, haddock, whiting, saithe, hake, black and white-bellied anglerfish, megrim, plaice, sole, herring, blue whiting, mackerel, horse mackerel, blonde ray, cuckoo ray, spotted ray and thornback ray. Data coverage is for the waters around Ireland from 10m to 180m in depth (Irish Sea, Celtic Sea, West and North of Ireland). The spatial coverage varied from year-to year. The sampling locations were selected from known fishing tracks while trying to ensure maximum spatial spread over the survey area. The surveys took place in February-March of 2004-2009. Samples were collected using a GOV bottom trawl (a scaled-down version of the IBTS standard, see: Manual for the International Bottom Trawl Surveys, ICES Survey Protocols SISP 1-IBTS VIII). The main purpose of the survey was to collect information on the length and age at which target species first reach maturity in the waters around Ireland. The surveys were carried out by the Marine Institute (Ireland) Fisheries Science team. All data collected on the survey are available.