Destruction and reinstatement of coastal hypoxia in the South ChinaSea off the Pearl River Estuary

Abstract

Abstract. We examined the evolution of intermittent hypoxia off the Pearl River Estuary during three cruise legs conducted in July 2018: one during severe hypoxic conditions before the passage of a typhoon and two post-typhoon legs showing destruction of the hypoxia and its reinstatement. The lowest ever regional dissolved oxygen (DO) concentration of 3.5 μmol kg−1 (~ 0.1 mg L−1) was observed in bottom waters during Leg 1, with a ~ 660 km2 area experiencing hypoxic conditions (DO