Toxic effects of red tide caused by Karenia mikimotoi on marine organisms

Red tide Caused by Karenia mikimotoi has become the main toxic algae bloom in China sea in recent years. For example, 12 red tide events caused by Karenia mikimotoi continuously happened in Chinese Zhejiang and Fujian provinces in 2012, resulting in a mass death of aquaculture animals, making economic loss of more than 2 billion Yuan. Toxic effects of Karenia mikimotoi on various types of marine organisms including of marine zooplankton, shellfish, fish and mammalian were discussed here based on summarizing domestic and foreign latest research progresses. The results showed that hemolytic toxin from Karenia mikimotoi was the main reason causing death of marine organisms. Directly contacting with live Karenia mikimotoi was the main way leading to zooplankton death; Karenia mikimotoi can produce hemolytic toxin and ichthyotoxin, which could lysis gill tissue of fish, then caused the fish death. However, the accumulation, migration and transformation law of Karenia mikimotoi hemolytic toxin in shellfish, the lethal way and the mechanism of Karenia mikimotoi causing abalone death, whether the hemolytic toxin change when transferring in the food chain and whether the toxins can damage human health and so on are not clear and need further research. Researchs about Karenia mikimotoi hemolytic toxin are still in the primary stage, questions like how toxin lead to red blood cells rupture, whether hemolytic toxin in the red cell membrane has specific binding sites, is there any corresponding relationship between hemolytic activity and erythrocyte membrane, should be further explored.