Coupling effects of nutrients and temperature for the hazard degree dynamic assessment of Karenia mikimotoi red tide disasters in the Wenzhou coastal waters

Abstract

How to quantify the response relationship between algal specific growth rate and marine environmental factors is the key to assess the hazard degree of red tide disasters. Firstly, a model for algal specific growth rate of Karenia mikimotoi based on the coupling effect of nutrient and temperature is established using laboratory algal culture data; secondly, the monthly hazard degree spatial distributions of K. mikimotoi red tide in Wenzhou coastal waters from January 2014 to December 2014 were obtained under the geographic information system (GIS) combining the MODIS satellite monthly average data with the assessment model. The results showed that (1) the algal specific growth rate relation model of K. mikimotoi was in accordance with Shelford's law of tolerance. (2) K. mikimotoi more likely caused red tide in Wenzhou coastal waters in May 2014 to July 2014, by contrast, it less likely induced red tide in other months of the same year. There are differences of the hazard degree of K. mikimotoi red tide disasters in the same months. These findings provide a technical basis to respond effectively to ecological disasters in Wenzhou coastal waters.