The State of the Lake
Thirty Year Study of Water Quality Trends in Lake George Released
A failure to address threats to the health of Lake George will irreversibly damage the lake’s water quality and the local economy, the authors of a thirty-year study of Lake George conclude.
The study, “The State of the Lake: Thirty Years of Water Quality Monitoring on Lake George, New York, 1980-2009,” was released this week by The Fund for Lake George, which financed the study.
While the study found that water clarity has decreased by 6% over the past thirty years, “the water quality of the lake remains exceptional, largely as a result of prudent management efforts,” states the report, which was written by Charles Boylen, Lawrence Eichler, Mark Swinton and Sandra Nierzwicki-Bauer of Rennselaer’s Darrin Fresh Water Institure and independent scholars Imad Hannoun and Jeffrey Short.
Thus while threats persist, there is reason for hope, said Eric Siy, the Executive Director for The Fund for Lake George.
“Human activities are largely responsible for the changes in water quality,” said Eric Siy, the executive director of The Fund for Lake George.
“But as a consequence, most of the causes of the lake’s degradation are within our control.”
The report is based on the Darrin Fresh Water Institute’s Offshore Chemical Monitoring Program, which was conducted by Boylen, Boylen, Eichler, Swinton and Nierzwicki-Bauer.
“Publication of The State of the Lake has been more than 30 years in the making and marks a major milestone for Lake George,” said Nierzwicki-Bauer, Darrin’s director. “Long-term data sets help us understand how we are subtly and significantly altering our environment. Without this kind of information we are subject to supposition, as to why water quality is changing, which greatly limits the ability of communities to act deliberately to protect water quality.”
Threats to the water quality of Lake George identified by the study include: rising concentrations of salt; nutrients from stormwater runoff, septic and sewage systems and fertilizers; and changes in the food web as a result of fish stocking or invasive species.
The salt used by highway departments to keep roads in the Lake George watershed free from winter ice has already damaged the lake’s ecosystem, and will wreak further havoc if current de-icing practices are not altered.
“The effects start at the base of the food web, with phytoplankton. As its composition changes, the lake becomes less able to support fish, birds, mammals and, for that matter, the people who like to eat fish,” said Short, who recently retired from a 31-year career as a research chemist at NOAA, where he worked primarily on oil pollution and other contaminant issues.
According to the study, concentrations of road de-icing salt have increased nearly threefold from 1980 to 2009.
Moreover, approximately 26,000 tons of sand are deposited on roads with the salt and eventually wash into the lake, contributing to the growth of deltas.
“These deltas provide rearing habitat for invasive species such as Asian clams and may introduce more phosphorus to the lake. This may eventually affect both the water quality and the ecological health of Lake George,” the report states.
“What’s literally feeding the lake’s water quality problems is land use activity in the form of new buildings, roads, drive ways and tree clearing, among other things. Since 1980, the Lake George watershed has seen a 62% increase in construction,” said Eric Siy.
Among the consequences of that heavy development is more algae in the south basin, where the development is concentrated, said Short.
The amount of phytoplankton in the lake, measured in terms of chlorophyll, increased by 33% between 1980 and 2009, the result, at least in part, of nutrients entering the lake from developed areas.
Rainbow smelt were introduced to Lake George in 1918 and 1929. The species has now established itself, and is, in fact, protected.
But the fish may have crowded out other species that feed on zooplankton, with the result that the lake is now richer in phytoplankton and producing more phosphorus than it would naturally.
Threats to nitella
Lake George’s famous clarity has been attributed in part to the existence of an aquatic plant called nitella, which actually absorbs phosphorus from the water column.
The plant not only protects water clarity, it depends upon clear waters for its survival.
As other plants proliferate, the nitella could be shaded and begin to dwindle.
“Once engaged, this feedback could rapidly reduce the lake’s water clarity and dramatically alter its food web, generally improving conditions for cyanobacteria and invasive plants and animals,” the report states.
As a result of the 1990 Clean Air Act, which mandated cuts in the emissions from coal fired plants that cause acid rain, concentrations of sulphates and nitrates in the lake have declined.
The lake also appears to be recovering from some of the pollution of the 1960s and 70s, before DDT was banned and the phosphorus levels of household detergents were limited.
“The clear success of these efforts confirms their utility in maintaining the high water quality and ecological stability of Lake George and other lakes like it,” the report states.
The dead zone in the south basin, for instance, might actually be shrinking rather than expanding.
Moving Forward: The Jefferson Project
‘The State of the Lake: Thirty Years of Water Quality Monitoring on Lake George’ serves as a springboard for the new generation of strategic research that is needed to secure breakthrough lake protection measures,” said Eric Siy. “With completion of ‘The State of the Lake,’ we have the foundations to move forward with the Jefferson Project, our collaboration with Rensselaer and IBM, dedicated to the fate of the lake and establishing Lake George as a global model for sustained ecosystem understanding and protection,” said Siy.
“The 30-year monitoring program looked at the lake through the lens of water chemistry. That data shows trends, but you can only infer so much. The Jefferson Project will build upon the monitoring program to develop a complete and comprehensive view of the lake’s ecology and ecosystem, from physics to fish,” said Siy.
Based at the Darrin Fresh Water Institute, the Jefferson Project will employ an array of new tools for applied research, said Siy.
“As we go forward, we’ll learn more; we’ll identify the influences on water quality and the actions we need to take to address them to make the lake healthier and more resilient,” said Siy.
According to Siy, the report’s recommendations are already guiding The Jefferson Project by informing its choice of research projects.
‘The State of the Lake’ clearly states what our priorities must be: maintaining the outstanding water quality of Lake George, which will require actions to reduce nutrient loadings, especially of phosphorus. Steps taken now to reduce salt loading in the Lake George watershed will help preserve the lake’s resilience to other environmental stresses imposed by rising water temperatures and invasive species. A better understanding of the effects of introduced and stocked fishes, as well as of invasive species, will serve to focus management responses or more efficient and practical solutions,” said Siy.