가막만 양식굴의 대량폐사에 관한 연구 Ⅱ. 부착생물 및 납작벌레

Mass mortality of oyster, Crassostrea gigas in Kamark bay Ⅱ. Fouling organisms and flatworms

Fouling organisms and flatworms have been investigated at mass mortality of oyster, Crassostrea gigas in Kamark Bay. Mean mortality of oyster were 76.85% (75.4~78.4%) in inner (st. 10, 11) of Kamark Bay, 23.61% (9.6~43.6%) outer (st. 1~4, 7~9) of Kamark Bay, and 54.7% (49.0~60.4%) in Baekdo (st. 5, 6), respectively. At surrounded oyster farm area, temperature and salinity were 1.5℃ and 0.0003 higher from August to september in 1996 than ordinary year (1990~1995). fouling organisms of oyster culturing beds such as Mytilus edulis, Balanus sp., Styela sp., Caprella kroeyeri, Tropiometra afra macrodiscus and Actiniidae were much in quantity(1~5 individuals per collector). And more organism malignant to oyster culture such as Stylochus sp. were found especially in all stations(3~43 individuals per hanging rope). Number of Stylochus sp. in Baekdo (st. 5, 6) and inner Kamark Bay(st. 10, 11) ranged 21~43 individuals per hanging rope. This suggests that the mass mortality of cultivated oyster is caused by aqua-farm environment and flatworms.