Acidification of Northeastern USA Lakes From Rising Anthropogenic-Sourced Atmospheric Carbon Dioxide and Its Effects on Aluminum Speciation

Summary/Abstract

Fossil fuel consumption, deforestation, and changing land use are all contributing to rising CO₂ concentrations in the atmosphere. In addition to atmospheric warming and climate impacts, rising atmospheric CO₂ will also promote acidification of ocean surface waters, which is expected to have detrimental effects on marine ecosystems. Much less is known about how rising atmospheric CO₂ will impact terrestrial freshwaters such as lakes and streams. In this peer-reviewed study, the authors developed reaction path models for 18 lakes from northeastern USA to investigate possible impacts of rising atmospheric CO₂ and temperature on these systems. These models indicate that acidification of these lakes could be of similar magnitude to ocean acidification. The study finds that the saturation state of these lakes with respect to the mineral aragonite, which is important for calcifying organisms, will also decrease. Finally, the authors find that acidification will alter aluminum (Al) speciation, which could augment toxic effects from this metal on important sport fish like brook trout, possibly reversing gains made in water quality since implementation of the Clean Air Act decreased the input of strong acids via acid rain.