Composition of Skipjack Tuna (Katsuwonus pelamis L) Taken by Commercial Fishery from the Northeastern Waters of Indonesia

The objectives of this study are to detect the changes in size composition of skipjack tuna, and to examine any association that may exist between skipjack tuna and other tunas taken from the northeastern Indonesian waters. Data were collected through a field survey by taken samples of catch of commercial fisheries in the study areas. Results of the study revealed that size composition of skipjack taken by pole-and-liners tended to be stable over the observation periods and was dominated by size class larger than 2.5 kg. However, there was a tendency of domination of skipjack for size class less than 1 kg, particularly taken by Bitung’s purse-seiners fishing around North Sulawesi water. It was also revealed that skipjack taken by the commercial fishery show a strong association with other tuna, especially yellowfin tuna.