Managing aquatic systems for ecosystem resilience and human well-being

Background/Question/Methods

The relationship between society and freshwaters is complex.  We have built our cities along rivers and protected bays.  We drink and grow our crops with water removed from rivers or pumped from belowground and expect these same water systems to contain or transport our wastes.  We invest enormous amounts of money containing, confining and directing the flow of surface waters to protect our property or to generate energy.  As we alter our landscapes to maximize commerce or agricultural yields, our activities generally reduce the residence time of water within watersheds and generate enhanced concentrations of sediments, nutrients and contaminants.  Collectively our consumption, control and contamination of freshwaters has brought us to a point where many parts of the world cannot depend on water availability now and most parts of the world cannot be certain of clean water supplies for future generations.  Most scenarios of climate change add to these worries by reducing our ability to predict future rainfall patterns.  In the face of these dire predictions, what can ecologists offer to enhance our collective stewardship of aquatic ecosystems?

Results/Conclusions

There is perhaps no realm in which ecologists have more successfully guided environmental management than in documenting how human activities alter the supply and quality of water to streams, lakes and oceans and in applying that knowledge to reverse or reduce the eutrophication, acidification and flow modification of aquatic ecosystems.  We must build upon these successes as we turn towards the next generation of challenges to freshwater ecosystem structure and function.  I will explore three important future directions for research.  First, we need to stop addressing water quantity and water quality as separate ecological issues so that we can begin to define clean water fluxes that are inclusively protective of aquatic organisms and human health and that explicitly incorporate hydrologic uncertainty into their maintenance.  Second, we must explore ways to design aquatic ecosystems at river basin scales that both facilitate the adaptation of aquatic organisms to future hydrologic change while simultaneously maximizing the provision of clean water fluxes downstream.  Finally, we need to find new intellectual partners to help translate relevant research findings more efficiently and effectively into the development and management of water resources.