Climate impact on hypersalinity in an Australian coastal bay

Abstract

[Abstract]: Recent work on episodes of hypersalinity in a subtropical east Australian coastal bay is reviewed. Hypersalinity is a response of coastal bays and estuaries to the local freshwater balance which fluctuates due to variable rainfall, river run-off, and evaporation. Longer lasting episodes of hypersaline conditions are a likely consequence of a drying and warming climate. The response of the coastal ocean to changes in the hydrological cycle has been observed in several Australian coastal systems, including the response to persistent drought conditions resulting in increased salinity and more frequent hypersaline conditions. In addition to observing hypersaline conditions in Hervey Bay off the central Queensland coast, first modelling experiments indicate that the frequency of hypersaline conditions has increased during the last twenty years. Coastal regions are important nurseries for Australian fisheries and the likely impact of persistent below average rainfall upon marine environmental conditions is yet to be assessed. This work indicates that routine monitoring of coastal salinity is essential in order to evaluate future impacts of climate change.