Role of temperature, salinity and ammonia on the occurrence of the Taiwanese strain of Alexandrium tamarense. In：T.J. Smayda and Y. Shimizu (eds.)

Abstract

The effects of temperature, salinity and ammonia on the growth of Alexandrium tamarense were tested to understand its occurrence in culture ponds in Taiwan. Alexandrium tamarense can grow at temperatures ranging from 16 to 33.5 °C, with the optimum at 28 °C. Salinities ranging from 5 to 40 ppt could support its growth with 10-35 ppt observed to be the optimum. Alexandrium tamarense died within one day when the NH4-N added to the media was more than 0.7 ppm at 15 ppt and 1.4 ppm at 30 ppt, respectively. All A. tamarense blooms observed were found to occur in culture ponds located near estuaries. This implies that they may have originated from the coastal waters along Taiwan then drifted into culture ponds and bloomed under suitable conditions for growth.