Dissolved oxygen in contrasting estuaries of the Bay of Biscay: effects of temperature, river discharge and chlorophyll a.

The article assesses the effects of temperature, river discharge and chlorophyll on variations of dissolved oxygen saturation in two contrasting estuaries in the Bay of Biscay. A description of geography, climate, macrotidal system, biotic community and ecological status in Bilbao and Urdaibai estuaries is presented. The vertical temperature and salinity gradients and eutrophication characteristics of the estuaries are presented. The water temperature, river discharge and dissolved oxygen-saturation variations are observed.