Dissolved organic nitrogen bioavailability indicated by amino acids during a diatom to dinoflagellate bloom succession in the Changjiang River estuary and its adjacent shelf

Graphical figure. Changes in a) the average concentration of DON and the percentage contribution of DON to TDN b), carbon- and nitrogen-normalized yields of TDAA; and c) the degradation index (DI) during the three bloom phases. Phase I: the termination of diatom bloom; Phase II: the initiation/growth of the dinoflagellate bloom; Phase III: the peak of the dinoflagellate bloom. Error bars represent the standard deviation except the DI (standard error shown). S: surface layer; M: middle layer; B: bottom layer.138