Shift of the fishing ground and features of shoals caught by purse seine fishery in the tropical seas of the western pacific ocean
Bulletin of Tohoku National Fisheries Research Institute 51: 75-88
This paper deals with the shift of the fishing ground, the features of shoals and the species composition of the Japanese purse seine fishery catch in the vicinity of northern Papua New Guinea. The purse seine fishing ground forms mostly in the area of the North Equatorial Counter Current and the South Equatorial Current. The shoals in the fishing ground are: (1) shoals with timbers; (2) shoals near the surface (with no object or animals); (3) shoals with whales (dolphins, sharks). In these shoals, the shoals with timbers have become the main object of fishing and skipjack tuna have been caught throughout the year. Major species caught by purse seiner included skipjack tuna (Katsuwonus pelamis, Yellowfin tuna (Thunnus albacores) and big eye tuna (Thunnus obesus). The skipjack tuna accounted for 58-73% of the total catch in 1977- 1986. Other fishes in the catch were blue marlin (Makaira mazara), black marlin (Makaira indica), common dolphin (Coryphaena hippurus) and rainbow runner (Elagatis bipinnulata). The Japanese purse seine fishery hardly competes with the pole and line fishery, but it does compete with foreign purse seine fishery in the fishing ground. For the purpose of avoiding this competition, it is necessary to officially exchange operational data with each other.