Energy Input in Marine Fisheries of Japan

Abstract

Energy input in the marine fisheries of Japan was estimated by use of the census data, i.e., Economy of Fishery Establishment and Fishery and Aquaculture Production. The total energy input as well as energy input per catch for each fishery type were estimated. The grand total of energy input for marine fisheries in 1980 was estimated at 6.0 x 1013 kcal (2.5 x 1014 kJ); the break-down of which was 28% for trawls, 19% for anglings, 18% for long-lines, 10% for purse seines and 10% for gill nets. The overall average of energy input per catch for entire marine fisheries was 0.60 x 104 kcal-kg-1 (2.5 x 104 kJ.kg-1), which is similar to or less than that in foreign waters. Tuna long-line on distant waters was the most energy intensive fishery type (3.5 x 104 kcal kg-1). On the other hand, small purse seine and beach seine required the minimun of energy (0.05 x l04~ 0.08x 104 kcal.kg-1). Energy input for catching each species of fish was also estimated. The most energy intensive species were marlins and tunas, whereas sardines and mackerels were the species which required relatively little energy. © 1989, The Japanese Society of Fisheries Science. All rights reserved.