By Kristen Wilde
LGA Director of Education
Another year of sampling by LGA staff and volunteers has determined that Lake George’s water clarity continues to be very high.
As one part of the Citizens Statewide Lake Assessment Program sampling, staff and volunteers measure water clarity using a Secchi disk, a world-standard tool. (CSLAP is a partnership between DEC and Lake associations and residents who help to monitor and collect important water quality data. This information is used by the LGA and the state to understand lake conditions and to develop lake management plans.)
At the Diamond Island sampling location (the location managed by me and our staff) the water clarity – or transparency – readings ranged from 5.8 meters (19 feet) on June 4 up to 9.2 meters (30.2 feet) on September 10, meaning we could still visually see the Secchi disk from the surface at those depths. The readings are similar to what we saw in previous years.
Lower readings in late spring are caused by spring stormwater carries a lot of material that can cloud the water, as well as because of Lake turnover.
Clarity readings exceeding 5 meters (16.4 feet) in New York State lakes are considered oligotrophic, or highly unproductive (low nutrients). As an oligotrophic lake, our water has low biologically useful nutrients like phosphorus and nitrogen; clear water; adequate dissolved oxygen; and low algae growth.
All of that supports the water clarity readings.
Besides water clarity measurements, the CSLAP sampling protocol delivers data on total phosphorus and total dissolved phosphorus, total nitrogen and total dissolved nitrogen, chlorophyll, temperature and pH of the water.
While we are waiting for the complete 2019 reports to be made available to us, all of the reports from previous years that we have received from New York State labs based on our sampling are on our website.
While the data from our CSLAP sampling has shown slight increases or decreases in those water quality indicators over the years we have been testing the water, none has shown a dramatic, long-term change.
For that, we are proud – it shows that the work of the LGA over the last century has been, and continues to be, protective of water quality. But the small increases or decreases are a signal that we need to continue our work protecting the Lake from pollution from stormwater runoff.
The sampling performed by LGA staff at the Diamond Island location was undertaken biweekly from June through September. Citizen scientists used the same protocols at three additional sampling locations: Basin Bay, Gull Bay, and Heart Bay.
Thank you to Bryan Wilcenski, Cindy and Steve Hughes, and Jill and Tom Cunningham for assisting us in collecting this important data so we can understand the water quality issues and conditions of Lake George.
WHAT IS A SECCHI DISK?
A Secchi disk is an eight-inch (20 cm) disk with alternating black and white quadrants. It is lowered into the water of a lake until it can no longer be seen by the observer.
This depth of disappearance, called the Secchi depth, is a measure of the transparency of the water. (Source: Our friends at the North American Lake Management Society: https://www.nalms.org/secchidipin/monitoring-methods/the-secchi-disk/what-is-a-secchi-disk/)