Interactions between suspended particulate matter and algal cells contributed to the reconstruction of phytoplankton communities in turbulent waters

The effect of turbulence on phytoplankton growth has been widely studied; however, its effects with respects to suspended particulate matter (SPM) on the development of phytoplankton communities and the behavioral responses of phytoplankton to turbulence and SPM are poorly understood. Here, an approximately homogeneous turbulence simulation system (AHTS, mainly consisting of an oscillating-grid apparatus) was established to gain insight into the mechanisms underlying phytoplankton community responses in turbid, well-mixed waters. The results revealed that maintaining the turbulence dissipation rates (Ɛ) of 2.25 × 10-3 and 1.80 × 10-2 m2/s3 caused significant reductions in algal density, and the effects could be substantially enhanced when 500 mg/L of SPM were added before day 12. In contrast to the constant decrease of algal…