Although concentrations of chemicals and pollutants like salt and nutrients have increased in the deep waters of Lake George, they’re still too low to harm the ecosystem at those depths, according to an analysis of nearly 40 years of data.

The Offshore Chemistry Program (OCP), run by Rensselaer Polytechnic Institute’s Darrin Fresh Water Institute, has been monitoring the deep waters of Lake George for 40 years. The Limnology and Oceanography paper, which also includes information on climate change, acid rain, and water transparency, presents results from the first 37 years. The analyses expand on an earlier report, published by Rensselaer and The FUND for Lake George, that assessed the first 30 years of data. That report inspired the creation of The Jefferson Project at Lake George, a pioneering collaboration of Rensselaer, IBM Research and The FUND for Lake George using advanced technology to vastly expand on the picture of the lake that the OCP produces.

«There are very few lake studies in the world that have given us such a wealth of information over time as the Offshore Chemistry Program,» said Rick Relyea, director of the Darrin Fresh Water Institute and the Jefferson Project. «Thanks to that long-term commitment, we have discovered that the deep waters of the lake are fairly resilient to human impacts. This insight has shifted our research focus from the deep water to the shallow water, streams and wetlands, places that are probably a lot less resilient and where most of the human impacts are being felt.»

William Hintz, lead author of the study and a former Jefferson Project researcher, said the trends — mostly defined by large percentage increases in still scarce chemicals — offer a useful heads-up.

«Levels of salt, the nutrient orthophosphate, and chlorophyll — an indirect measure of the floating algae that feed on orthophosphate — have increased substantially, but as far as we can determine, none are at a level that will cause harm, and that’s good news,» said Hintz, now an assistant professor at the University of Toledo. «We’re fortunate to have this early warning. We know how to bring those levels back down, and we have time to reverse these trends before they cause harm.»

«Updated findings of the lake’s offshore chemistry program demonstrate the continuing resilience of Lake George to a growing array of stressors while also underscoring the need to focus research closer to shore and the human activities associated with increasing pressures on water quality — from wastewater and stormwater to road salt impacts,» said Eric Siy, executive director of The FUND for Lake George. «The groundbreaking work of the Jefferson Project is responding to this need to gain a fuller understanding of lake and watershed conditions that can inform policy measures designed to maintain the lake’s outstanding water quality,» Siy said.

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