Fig. 4

Hourly variation of \({b}_{\mathrm{bp-index}}\left(green\right)\) on the bloom days of P. donghaiense on May 12, 2016 and K. mikimotoi on June 30, 2017. The black represents the \({b}_{\mathrm{bp}-\mathrm{index}}\left(green\right)\) from P. donghaiense blooms, the black dotted line represents \({b}_{\mathrm{bp}-\mathrm{index}}\left(green\right)\) from the K. mikimotoi blooms