Algae. 2007; 22(3): 241-246.
Cochlodinium Red Tide Effects on the Respiration of Abalone, Haliotis discus hannai Ino
Kyung Suk Seo1* and Chang Kyu Lee2
1Resources Development Technology Team, KIMST, 275-6 Yangjae-Dong, Seocho-Ku, Seoul 137-941, Korea
2Marine Ecology Research Team, NFRDI, 408-1 Sirang-Ri, Gijang-Eup, Gijang-Gun, Busan 619-902, Korea
Cochlodinium polykrikoides -related red tide is the most notorious tidal bloom, resulting in mass mortality to marine animals. This study aimed to test the effect of C. polykrikoides on the lethality to Haliotis discus hannai under controlled conditions. The oxygen demand of C. polykrikoides increases to reach its peak during the night, while the oxygen usage by H. discus hannai was continuously decreased with a threshold of 2 mg L?1. The addition of C. polykrikoides did not effect the respiration of the H. discus hannai. However, the usage of oxygen by C. polykrikoides during the night may lead to anoxia in the animal. With aeration, the level of dissolved oxygen (D.O.) was between 6.06 and 7.28 mg L?1; 90% of abalones survived even with a high concentration of C. polykrikoides (9000 cells mL?1). Without aeration (3 mg L?1 of D.O.), however, the H. discus hannai suffocated immediately. Once 20 hours had elapsed, all of the abalones were dead. The density of the H. discus hannai population contributed to their mortality. Therefore, aeration during the night and maintaining lower abalone densities is the best way to promote the survivorship of H. discus hannai during a C. polykrikoides red tide.
Keywords : Cochlodinium polykrikoides, dissolved oxygen, harmful algal bloom, Haliotis discus hannai, lethality test,