an analysis of stomach contents of skipjack tuna Katsuwonus pelamis and plankton samples collected during troll fishing operations showed that the abundance of some dominant organisms in tuna stomachs was related to their abundance in the plankton. Fish larvae mainly pilchards, Nyctiphanes australis, brachyuran and other decapod larvae and calanoid copepods are important food item for skipjack. The copepods Undinula vulgaris and Nannocalanus minor occurred consistently throughout the survey period in both stomach contents and plankton samples. U. vulgaris appeared to be a preferred food considering its high percentage composition in tuna stomachs compared with its low percentage composition in the plankton. Temora turbinata and N. minor may also serve as important food items for skipjack. The largest catches of the fish were made in January and February when plankton organisms were composed dominantly of N. australis, copepods and brachyuran larvae. The main stomach contents during this period were N. australis and brachyuran larvae.