2003 Volume 67 Issue 1 Pages 1-8
Most of white-spotted conger eel fisheries in Osaka Bay have been carried out by basket trap fishing boat and a radar installed at the Kansai International Airport monitored tracks of the fishing boat to know fluctuation in fishing grounds during January 1-December 31, 2000. The radar tracks indicated seasonal fluctuation in fishing grounds. During January-March, fishing ground was formed mainly around the southwest area of the Bay, 30-40m in depth. During April-June, it moved along the somewhat east side of the Bay and was formed in the central and inner area of the Bay, less than 20m in depth. Particularly, during June 16-July 21, fishing ground in the inner area of the Bay disappeared with hypoxic water development, and it was formed concentrically at the outside margin of the water, 40% or less oxygen saturation. During August-September, fishing ground was not formed, because of the catch declining and few fishing boats. During October-December, fishing ground was formed mainly in the southwest area of the Bay, subsequently; it spread to the all area of the Bay. It was considered that these fluctuations in fishing grounds corresponded to the seasonal migration of white-spotted conger eels in Osaka Bay.
