Modeling of competition and succession between red tide causing Chattonella and diatoms

Role of vertical mixing and nutricline depth

Abstract

Outbreaks of Chattonella antiqua (Hada) Ono (Raphidophyceae) red tides usually occur as a consequence of phytoplankton spices succession which is a result of competitions. C. antiqua is a motile phytoplankton and capable of diel vertical migration and nocturnal nutrient uptake. On the other hand, diatoms are not motile and settle when the mixing is suppressed. We have developed a model to simulate the succession and competition between C. antiqua and Skeletonema costatum (diatom) with taking these different features of two species into account.
The effect of vertical mixing and nutricline depth on above two species was estimated in this paper. Simulation results showed the absence of mixing is necessary for C. antiqua to be dominant. Since our model considered the ecological features of different phytoplanktons properly, it is able to explain the succession due to physical condition effects. Our model showed the potential to simulate the plankton species succession depending on environmental changes.