Evaluation of Impacts of Environmental Factors and Operation Conditions on Catch of the Coastal Squid Jigging Fishery-Does the Amount of Light Really Matter ？

摘要

Factors that influence squid catch of the coastal squid jigging fishery were analyzed using data sets recorded by 9 boats in Tsushima Strait in January and February 2010 including daily catch amount, lighting pattern of fishing lamps, presence of dolphins during operations, and the number of other jigging boats operating within 2 nautical miles from the boat. Generalized linear modeling analysis indicated that catch is explained by the fishing ability of the captain and crew of each boat, illuminatedfraction of the moon (lunar phase) and presence of dolphin, with assuming monthly differences in squid abundance. Influences on lighting patterns of fishing lamps and number of operating boats around the boat that fishermen always have keen interests are not detected in the analysis. The factor of fishing ability of the captain and crew of the boat may be interrupted as the ability to search the promising fishing locations in the fishing ground. Furthermore, presence of dolphin showed a negative impacton catch.