Commercial marine fishery statistics (until 2016, Professional marine fishery statistics) are based on periodic catch declarations by commercial fishermen. A commercial fisherman may be a natural person (person or business) or a legal person (limited liability company, limited partnership or general partnership), engaged in fishing for commercial purposes. According to the Fishing Act (379/2015), all commercial fishermen must be entered in the register on commercial fishermen and the Act on the registration of fishing and aquaculture vessels operating at sea (690/2010) obliges all vessels and boats engaged in commercial marine fishing under a Finnish flag to be registered. Both registers are maintained by Southwest Finland Centre for Economic Development, Transport and the Environment. In Åland, the Provincial Government maintains a register of fishing vessels engaged in commercial fishing. The regionalization used in the statistics is consistent with the spatial classification of the International Council for the Exploration of the Sea (ICES). Catch statistics are presented in accordance with international practice as a nominal catch. Nominal catch refers to catches landed by fishermen in Finland or abroad or transshipped at sea. For statistical purposes, this is reported in kilograms live weight, i.e. the weight of ungutted fish. Discarded fish, for example fish damaged by seals, are not included in the nominal catch. The catch is reported by species and fishing gear. The amount of catch is calculated separately for each species based on nonzero observations during the reporting period and presented in trap net, gill net, trawl and hook days. For instance, trap net fishing with two trap nets over ten days accounts for twenty trap net days. The reporting period is one fishing effort in the fishing logbook and the landing report of coastal vessels of less than 10 metres length, and one month on the coastal fishing report. The catch per unit effort (CPUE) is given as the quantity of catch in kilograms (kg) per fishing gear and 24 hours of fishing. The CPUE per species is also calculated for non-zero catch observations only. The number of units of fishing gear is calculated as the sum of fisherman-specific highest numbers of units of gear simultaneously used for fishing. The number of fishing days is the total number of fishing days of all fishermen for the gear in question, regardless of whether or not there was a catch. Fishing gear is used for different lengths of time and its number varies. This variation is taken into account in fishing gear days (trap net, gillnet and trawl days), for example five days of fishing with ten nets totals fifty net days.

1953