Occurrence and Abundance of Japanese Sardine Eggs from 1983 to 1993 in Kagoshima Bay, Southern Japan

Occurrence and abundance were studied on the Japanese sardine eggs collected from 1983 to 1993 with a larval net at 9-14 stations in Kagoshima Bay, southern Japan, totalling 1554 collections from 121 cruises. Abundance of eggs showed extreme variations in space and time : for example, the annual abundace of eggs varied from 1 of 1985/86 to 11654 of 87/88 in the bay total, and from 0 to 7509 among stations in the most abundant year 87/88. The annual abundance of eggs was negligible in 85/86, nearly equal in 83/84 between the northern and southern parts of the bay, and higher in 84/85, 86/87, and 87/88 at the northern part and in the other years at the southern part. There was no significant correlation between annual landings of Japanese sardine from the bay and annual densities of eggs. During the period of occurrence of eggs from October to April, peaks of density appeared at the first half (November or December) and/or at the latter half (February or March). Densities and frequencies of occurrence of eggs showed roughly a positive correlation. According to the interview to fishermen in the bay, main fishing season of Japanese sardine was autumn to spring