Hervey Bay and its estuaries

Hervey Bay and its estuaries

Hervey Bay and its estuaries are located along the east coast of Australia just to the south of the Great Barrier Reef Marine Park. The region has long been recognised as one of Australia’s most biodiverse marine environments and including the Great Sandy Strait in the south of the Bay, it is referred to as the Great Sandy Biosphere. The United Nations Educational, Scientific and Cultural Organisation (UNESCO) included the area in its list of 580 designated biospheres located in 114 countries.
Although widely recognised for its exceptional biodiversity, little is known about the physical processes and climate characteristics that shape its natural marine environment. Only recently, the Bay has been classified as a large low inflow and predominantly hypersaline system. River runoff and discharge from its many estuaries is very small. It has almost been absent during the Australian Millennium Drought lasting the first decade of the 21st century. During other times, freshwater inflow is only significant following flooding as a result of tropical/subtropical depression, which often is amplified during La Nina events. A positive freshwater balance leads to a net loss of water establishing hypersaline condition. This appears to prevail throughout the year and is re-established shortly after storm events. Hydrodynamic modelling suggests that predominant southeasterly to easterly trade winds establish a cyclonic water renewal pathway, with Hervey Bay water existing along the western shoreline. Hypersalinity and the characteristics of an inverse estuarine circulation are evident from observation and modelling.

This chapter reviews our understanding of the environmental processes that shape Hervey Bay and its estuaries in the context of its climate. Future changes in the regional freshwater balance indicate a continued trend toward drier and warmer conditions. It leads to an intensification of hypersaline and possible inverse circulation states of Bay. Insight into the environmental forces shaping Hervey Bay, its estuaries, and a unique and biodiverse environment, informs continued sustainable natural resource management and policy development. It is anticipated that over the next few decades physical processes associated with climatic trends and variability are likely to impact more dramatically upon the natural environment of the region than direct human activities such as fishing, aquaculture, tourism and continued local population trends.

Copyright Springer Science+Business Media Dordrecht 2014.