An interaction between fisheries resulting from the impact of one fishery using a particular technology (e.g. trawl gear) on another fishery, usually using a different technology (e.g. pots), but exploiting the same resources as target or bycatch. Because of their importance, the cross-impact of various fleets targeting overlapping species groups must be assessed. Major source of failure in total allowable catches (TACs) and quotas management strategies for multispecies and multigear fisheries.