This dataset contains information on benthic infaunal abundance and biomass from sediment grabs and video footage from off the Copeland Islands in Belfast Lough in late 2017 and early 2018 on the RV Corystes. This survey was carried out to describe the species and seabed habitats within a 0.5NM buffer zone of a dredge disposal site. The survey was carried out pre and post operation to allow the potential impacts to be investigated. In total there were 29 grab samples taken and analysed and 4 video tows carried out and analysed. Particle size analysis (PSA) and Carbon and Nitrogen analysis were also carried out on the sediments from the grab samples. All grab samples contained fauna species with the most abundant being Balanus cretanus and the most frequently recorded being Sabellaria spinulosa. The most frequently recorded species on the video tows were Spirobranchus triqueter and Balinidae.