2021 ESA Annual Meeting (August 2 - 6)

Climate change and the environmental flow requirements of estuaries

On Demand
Janine Barbara Adams, Coastal and Marine Research Institute, Nelson Mandela University;
Background/Question/Methods

Freshwater inflows are vital to the ecological health of estuaries. However, these flows are modified by anthropogenic activities and small changes in baseflow can result in major changes in the ecological integrity of estuaries. The management of environmental flows is complicated by the effects of climate change, which place multiple pressures on estuaries including sea level rise, changes in mouth dynamics, alterations in temperature and precipitation patterns and changes in the intensity and frequency of extreme events such as sea storms, floods, and droughts. This studied investigated innovative management responses to changes in freshwater inflow to estuaries.

Results/Conclusions

Some management interventions include artificial breaching of the mouth and the release of water from dams. However results show that these cannot replace natural flow regimes and must be practiced cautiously as they can lead to unintended impacts. Managing the environmental flows of estuaries is challenging because each system has unique characteristics that determines their sensitivity to changes in freshwater inflow. Long-term monitoring that applies a catchment-to-coast approach is necessary to produce high confidence data to understand the environmental flow requirements of estuaries and potential responses to climate change. Such monitoring is successful in improving the resilience of estuaries when applied in a strategic adaptive management cycle.