Squam Lakes Ecological Monitoring

The SLA was the charter participant in the NH Lay Lakes Monitoring Program (NH LLMP) in 1979, a volunteer monitoring program coordinated by UNH Freshwater Biology Group. SLA also monitors the spread of invasive plants, such as varible milfoil, through the NH DES Weed Watchers program.

The NH LLMP was designed to address acid rain and the greening of the lake, called "Eutrophication". Monitoring tests are concerned with neutralizing capacity (alkalinity), water clarity, algae levels and nutrient levels, primarily Phosphorous.

Overall the lakes show very good water quality with average seasonal (summer) water quality testing always well within the limits for a pristine lake. However, certain areas of the lakes are displaying more productive (more algae and weeds) conditions during certain years and some areas are approaching less pristine conditions at a faster rate than natural processes should dictate. The type of weather year and climate change has caused quite a variation in the water quality of the Squam Lakes as well as other lakes in the state.

Water Transparency is measured in meters using a secchi disk, which is lowered from a boat and viewed through a viewscope, which minimizes glare and reflections. The measurement is taken at the average of when the disk disappears and reappears. Deeper secchi disk measurements (over 5 meters) reflect pristine water quality. Algae blooms, which result from nutrient (phosphorus and nitrogen) loading decrease water transparency. The above chart of Cotton Cove shows a gradual decline in water quality from 6.7 meters to 5.5 meters. Click below to view a Water Transparency Chart for other locations on Squam:

SLA relies on volunteers to collect water quality data at 12 locations around the lakes. Volunteers collect clarity data (Secchi Disk) weekly and integrated water samples for algae and clorophyll concentrations bi-weekly. If you live near Squam and would like to be involved in the water quality monitoring program, please contact Info@squamlakes.org or call (603)968-7336.