Warming-induced changes in benthic redox as a potential driver of increasing benthic algal blooms in high-elevation lakes

Algal blooms appear to be increasing on benthic substrates of naturally nutrient-poor lakes worldwide, yet common drivers across these systems remain elusive. The phenomenon has been notable in high-elevation mountain lakes, which is enigmatic given their relative remoteness from human disturbance. We suggest that warming-induced changes in redox conditions that promote nutrient release from sediments warrant more attention. Warming associated with climate change reduces oxygen content and hastens microbial processes, enhancing release of nutrients which can be intercepted by the benthic algae before reaching the water column. Warming effects may be particularly noticeable in high-elevation lakes that hold less oxygen at saturation, are warming more rapidly than lowland lakes, and can receive relatively high solar radiation.