Conway Lake Sunrise - photo courtesy of Mark Guerringue
What's New on the Lake
Work on the New Boat Ramp is Complete
Work on the new boat ramp on Mill St. is complete and the lake is gradually being raised to winter levels (the lake is rising by about a half inch per week). The new ramp includes a gravel and rock base, two steel I-beams running the length of the ramp, and preformed concrete pads laid on top of the I-beams. The ramp has a perimeter of coarse rocks to protect it from erosion.
The completed boat ramp prior to raising the lake. Once the lake returns to normal levels the last 5 or 6 concrete planks will be underwater. Photo courtesy of Rick Blank
Invasive Spiny Water Flea Found in Lake Winnipesaukee!!
The spiny water flea was discovered in Lake Winnipesaukee this September, marking the first time this aquatic invasive species has ever been detected in New Hampshire. The tiny animal was likely introduced to the lake by boaters who visited a waterbody with an existing infestation, and carried eggs or live organisms on fishing or recreational gear, or in the bilge or live well of a boat.
The nearest locations of other infestations include Lake Champlain in Vermont as well as Lake George and a few other waterbodies in New York.
Unfortunately, it will be difficult to spot by our Lake Hosts because of its minute size and there is currently no way to control the species once it enters a lake. The best and only management option is to prevent its introduction into uninfected waterbodies by cleaning, draining and drying all boats and recreational gear after leaving a waterbody, as required by New Hampshire state law.
Why this is significant: While not harmful to humans, spiny water fleas affect the overall ecosystem of a lake by competing for zooplankton that fish and other aquatic animals feed on, thereby reducing the fish population and wildlife that feed on the fish.
Cyanobacteria Blooms on the Rise in New Hampshire Lakes
Cyanobacteria are photosynthetic bacteria that occur naturally in lakes, but when conditions are right (abundance of nutrients, e.g. phosphorous and nitrogen), they can multiply rapidly and create blooms on the surface of the lake. Some cyanobacteria blooms produce toxins (“cyanotoxins”) that are harmful to animals and humans. Blooms are occurring more frequently in NH lakes and the NH DES now has an interactive map that allows you to see which lakes currently have advisories or warnings. Check it out: https://experience.arcgis.com/experience/180c28fa3a4c4371a9771d999454e8c4/.
If cyanobacteria density in a lake or pond exceeds the state’s recreational threshold an advisory is issued and all public access to the lake will be closed until the lake tests negative.
-
To learn more about cyanobacteria check out the CLCA Invasive Species webpage.
-
If you see a film on the surface of the lake that you feel could be a cyanobacteria bloom contact Maria Gross or Don Yurewicz and they will take a look.
By Don Yurewicz
Potential Causes of Increased Phosphorous in Conway Lake
By Bill Petry
As reported in the 2023 Spring Newsletter, we detected a significant increase in Lake water phosphorous during the UNH testing carried out on August 15, 2022, and want to understand the cause of the increase and, if possible, mitigation steps. In the Newsletter article we stated that the most likely cause of the increase might be excessive shorefront development with violations to the
Town of Conway's shorefront protection regulations.
Our UNH partners who have supported our Lake water testing for the last 40 years have suggested there are five potential sources for the increase, and we discuss each in the paragraphs below.
Click here to read more about potential factors that can explain the increases in lake phosphorous
Update - Remapping Conway Lake Bathymetry
The project to remap water depth across Conway Lake was completed in late 2022. Click here to read more the project and the new maps.
Snapshot of 2022 Updated Depth Map.
