The transfer process of fish or fish products at sea or in port, from one fishing vessel to either another fishing vessel — or to a vessel used solely for the carriage of cargo, for further transport. At‑sea transshipments are of special concern in fishery management since, if not properly monitored, they can complicate the collection of accurate data and the traceability of product, creating a fertile environment for illegal, unreported, and unregulated fishing activities.

See also Illegal fishing, Unreported fishing and Unregulated fishing.