Warming lakes put human wellbeing in hot water

As the planet warms, science increasingly reveals the particular impacts that climate change will have on different ecosystems. For instance, recent research has revealed that aquatic ecosystems, particularly lakes, are primary indicators of climate change and are increasingly subject to shortened periods of ice cover and a shift in lake stratification patterns, affecting lake biodiversity and water quantity and quality. Writing in BioScience, R. Iestyn Woolway of the University of Reading and colleagues describe the myriad impacts climate change is expected to have on lakes, the ecosystem services they provide, and which areas of research most urgently need further exploration.

According to the authors, shorter winters in the Northern Hemisphere have resulted in 31 fewer days of ice coverage over the past 165 years, with many lakes poised to lose even more. The article describes a series of cascading impacts ranging from altered lake biota and greater water loss from evaporation to increasing salinity. Woolway and colleagues also point to direct anthropogenic uses of lake water (primarily for agriculture) as a major factor in the decline in quantities of lake water. Runoff from industrial and agricultural sectors, in combination with longer summers, has led to an increase in algal blooms that deteriorate water quality and ultimately leave lakes starved of oxygen.

As lake water quality deteriorates, the ecosystem services provided by lakes can be expected follow suit, according to the authors. For instance, the United Kingdom’s biggest wild swimming event, the Great North Swim, was cancelled in 2010 as a result of algal blooms, and the availability of fresh drinking water may soon be threatened.

To conclude, the authors pivot to potential areas for further research, highlighting the complications posed by altered aquatic ecosystems. Although many of climate change’s effects remain unforeseen, the authors point to the potential for community science and recent technological advances to help managers better understand lakes in our warmer future. To protect waters and ensure equitable access, they say, "the inclusion of diverse voices from researchers worldwide, including the Global South, and the cross-pollination of ideas across disciplines, will be essential."