Unmonitored Water Bodies – a Safe Haven for Invasive Species

Special to Ossipee Lake Alliance

Freedom–October 6, 2013–What lurks beneath the unwatched depths of 79 of the state’s water bodies? The answer is weeds — destructive and invasive non-native species of milfoil in particular. According to an updated survey conducted by the Ossipee Lake Alliance, 21 infested ponds, lakes and rivers are not actively managed on an ongoing, local basis to control their invasive, aquatic species. However, four on the list have received occasional assistance from the New Hampshire Department of Environmental Services (NH DES) or the U.S. Army Corps of Engineers.

“Every year, we scrutinize how much money is spent to control milfoil, where it’s spent, and how that money is raised,” commented Bob Reynolds, Executive Director of the Ossipee Lake Alliance. “Almost $900,000 was spent last year trying to control milfoil statewide.  But that was in only 70 percent of the infested lakes and rivers.  It’s alarming that 30 percent of the infested water bodies are not being actively monitored and controlled, and those infestations will only increase in size and cost to control them.”

Unchecked infestations could cause economic damage, as well. Decline in New Hampshire’s surface water quality and clarity could negatively impact tourism, property values and result in millions of dollars in lost sales and income, according to a four-phase economic study conducted over five years. In 2001, the Lakes, Rivers, Streams and Ponds Partnership, comprised of many lake and river non-profit organizations and state agencies, kicked off a four-phase study to determine the extent to which surface waters contributed to the state’s economy.  One of the surveys in that study showed that perceived degradation to water clarity and purity would result in $51 million in lost sales, $18 million in lost income, and 800 lost jobs.

According to Amy Smagula, the Exotic Species Program Coordinator at the NH DES, the state has a total of 79 infested water bodies, 70 of which contain variable milfoil as the primary invasive plant, while others have fanwort, Eurasian water milfoil, water chestnut and Didymo, also known as rock snot, an invasive algae. While the majority of these infested water bodies have localized or regional monitoring and/or treatment plans in place, there is concern over the remaining unmonitored infested waterways. Rampant, unchecked growth of variable milfoil is difficult and expensive to remove.

“The biggest issue is we can most effectively control or eradicate invasive species if we get to it at a point when the infestation is small and localized,” said Smagula, stressing that early detection and milfoil growth prevention are key in protecting the health of our lakes and rivers.

“If it gets to the point where you find a 20-acre infestation in a pond, that’s harder to deal with,” she said. “Integrated management is key to long term success,” Smagula said during a presentation to members of the Lakes Region Planning Commission this spring, where she also stressed community members be proactive rather than reactive in their milfoil control efforts.

Last year, NH DES warned of expanding infestations of exotic plants after new infestations were documented at Otter Lake in Greenfield and Naticook Lake in Merrimack.

“Both infestations were well-established when found and appear to have been present for at least two to three years before being reported,” she said. Neither of the lakes had established programs for prevention and early detection, to milfoil growth went unnoticed until they covered large areas, she said.

Freshwater exotic aquatic plants, she explains, are those that are not found naturally in the state’s lakes, ponds and rivers, and because they are not native, they have no predators or diseases that keep them in check, allowing them to grow quickly. These invasive plants dominate the shallows of freshwater systems to the detriment of native plants, fish, aquatic insects and other aquatic life. The growths can reduce water quality, shorefront property values, and can damage the aesthetic and recreational values of lakes and rivers.

On the list
According to the June 2013 listing compiled by the Ossipee Lake Alliance, the following infested lakes and rivers have no localized invasive species control efforts:

Bixby Pond in Epsom; Brindle Pond in Barnstead; Cheshire Pond in Jaffrey; Kimball Pond in Hopkinton; Powder Mill Pond in Hancock; Spaulding Pond in Milton; Turtle Pond in Concord; Upper Goodwin Pond in Concord; Ashuelot River in Winchester; Cocheco River in Rochester; the Connecticut River in Charlestown; the Contoocook River in Jaffrey; Little Suncook River in Epsom/Northwood; the Merrimack River in Concord; the Squam River in Ashland; and the Winnipesaukee River in Tilton. Hopkinton Lake in Hopkinton did receive spot control by the U.S. Army Corps of Engineers; NH DES provided some assistance with divers at the Pemigewasset Lake in the Meredith/New Hampton area, and in Dover at Willand Pond. NH DES also provided some treatment this year at the Piscataquatog River in Goffstown, and, lastly, the U.S. Army Corps of Engineers provided some control activities in 2012 and this year at the Pemigewasset River in Sanbornton.

State funding and teamwork
In 2012, NH DES Exotic Species Program distributed approximately $215,000 to 27 different groups for milfoil control efforts. Smagula said it was too early to say how much funding will be available this year, but in the past, demand has exceeded supply. Aside from requesting state funding, municipalities can support warrant article requests for milfoil control. Smagula works throughout the year with municipal groups, lake association, milfoil committees, conservation commissions and others to help design milfoil control programs. She stresses the effort takes teamwork and communication.

“No invasive aquatic control project in the state has ever been successful without a cooperative effort between state and local entities,” she said.


  1. Bill Elliott 11 years ago October 17, 2013

    I had the opportunity to listen to a presentation on this subject by Mr. Reynolds this past Tuesday. It was done very well. The above is a good read. I enjoyed the complete article and especially paragraphs two and three. When people think of the invasive aquatic species, such as milfoil, they don’t think that it will effect them when in fact it does as outlined. It is my understanding that the State of New Hampshire prides itself in that it owns the waters of NH and the land underneath. They should be the leader to “cut their grass”, being the invasive aquatic species that are invading our water systems rather than the local communities surrounding the waters.

  2. Paul Miller 11 years ago October 19, 2013

    Last year I reported Mil-foil in the Pine River. It had to have originated in Pine River pond. To my knowledge, nothing was done to correct this. This will keep Ossipee infested until someone deals with the source.

  3. Bob Reynolds 11 years ago October 20, 2013

    We reported the Pine River milfoil infestation (where it empties into Ossipee Lake) to DES last year and they quickly brought their divers in to hand pull it. DES checked it again this year, and a small infestation still exists. It is now being managed by the Ossipee Conservation Commission as part of the Ossipee Lake Milfoil Management Plan. We’ll ask them to look for “source” infestations in Pine River Pond.

  4. Lisa 11 months ago August 5, 2023

    Right now at 3:17 there are 3 pontoons beached at long sands. One group has at least 20 people on lawn chairs with tables right under the restricted sign. So entitled. Called marine patrol but looks like they are not on lake today.


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