Abstract

This study was conducted to get a basic information on the avoidance effects from shell-boring and biofouling on a bay scallop (Argopecten irradians) cultivated in Jaran Bay, located on the southern coast of Korea by applying three different submerging times from May, August, and September 2023. A significant difference in the biomass of biofoulers on the scallops was observed between the two submerging periods in August and September. The mean biomass of biofoulers attached on the shells of scallops submerged in Jaran Bay during August, 2023 was highest as 6.3 g wet/scallop corresponding to 14% of the mean scallop biomass, and decreased to 1.8 g of scallops submerged in May and 0.7 g in September. The dominant biofoulers on scallops submerged in August were barnacles and juvenile oysters, whereas scallops submerged in September were primarily fouled by juvenile barnacles, with no juvenile oysters observed. The mean number of blisters made by shell-boring worms per scallop shell was highest as 1.5 in the scallops submerged in May, but it decreased to 0.9 and 0.3 individuals from scallops submerged in Aug. and Sept., respectively. There were no significant correlations between the fresh weight of scallops and the shell-boring worms or biomass of fouling organisms during this study period. This finding is significant for the scallop cultivation industry because the growth rate of scallops submerged in September was comparable to the somatic growth rates of scallops submerged during spring and summer.