Numerical Mesocosm Experimental Study on Harmful Algal Blooms of Two Algal Species in the East China Sea
Table 1
Comparison between indoor culture, field mesocosm, and numerical mesocosm.
Mode
Indoor culture
Field mesocosm
Numerical mesocosm
Location
Culture dishes
30°50.5′N, 122°6.7′E
~120°00′E–124°00′E, ~27°00′N–30°45′N
Species
S. costatum and P. donghaiense
S. costatum and P. donghaiense
S. costatum and P. donghaiense
Physical environment
Artificial light source Fixed thermohaline value Still water
Natural light Local water temperature and salinity No current impact
Parameterized irradiance Simulated thermohaline value Simulated current
Nutrient condition
Artificially added culture medium
Artificially added nutrients
Simulated nutrient concentration nudged towards observations
Exchange with outside
None
Artificial circulation
Numerical boundary conditions
Results
(a) Adaptive temperature range of exponential growth phase for these two species (b) S. costatum is more competitive in a rich nutrient environment (c) P. donghaiense can live in low nutrient environment
(a) Maximum growth rates of these two species (b) S. costatum can proliferate rapidly under high nutrient conditions and has a shorter duration of bloom (c) P. donghaiense can survive under nutrient-limited conditions and its blooms persist over a longer period
(a) Simulation of the algal blooms caused in turn by these two species further confirms the competition mechanism between them (b) The current contribution to the northward migration of the bloom center (c) The lack of nutrient supplement in the open sea limits HAB occurrences in the coastal waters
