The report for authorities and scientists provides an overview of substances that can be released into the marine environment from various offshore industries and estimates the quantities of pollutant inputs. These may be relevant as additional contaminants according to European Commission Decision (EU) 2017/848 for Descriptor 8, Criterion D8C1. In addition to the potential hazardous substances from the offshore wind and offshore oil and gas industries, which were published in sub-reports 1 and 2 of the RESOW project, three other offshore sources are considered in this report: Mariculture, maritime transport and (historically) dumped munitions.