長崎県北部沿岸域におけるトビウオ未成魚の漁獲量変動要因

抄録

The catch of young flying fish, Cypselurus hiraii and Cypselurus heterurus doederleini, by boat seine fishery in the northrn coastal waters of Nagasaki Prefecture, Japan shows wide yearly fluctuations. The effects of five factors on the fluctuations were recognized by multiple regression analysis using data from 1976 to 1987. The factors are as follows: annual catch of adult flying fish by 9 set-nets in the coastal region of Yamaguchi Prefecture (X₁); average surface water temperature in July (X₂) and catch by FADs of dolphin fish as predators in August (X₅) in the offshore region of Yamaguchi Prefecture; days of north-east wind at Hirado Meteorological Station, Nagasaki Prefecture (X₆); and number of boat seine belonging to Ikitsuki Fisheries Cooperative Association, Nagasaki Prefecture (X₇). The relationship of the annual catch of young flying fish at Ikitsuki Fisheries Cooperative Association (Y) to these factors is as follows:
Y=-2221.9+0.210X₁+96.287X₂-1.765X₅+4.040X₆+8.139X₇
The regression is significant at the 1% level. The estimated annual catch closely follows the trend of the actual catch. The actual values of the catch in 1988 and 1989 are within the confidence margins at the 95% level. Thus, the equation can be used to predict the catch for the next fishing season.