Fighting a Milfoil Infestation

It’s Not Easy! It’s Not Cheap!

by Laurie Vance  • MPA Vice President

If anyone wants confirmation that the work and dollars contributed to the Moose Pond Association are valuable, drive over to Sebago Cove, the Songo River or certain Long Lake areas. There you can watch the incredible Milfoil infestation remediation efforts. Just down the road we can see the impact of a long-term infestation on property, boating and lake living first hand

Less than 20 miles from the Route 302 boat launch, the Lakes Environmental Association (LEA) runs teams who work to stem the spread of Milfoil and keep reported infestations in control. The three primary methods used are benthic barriers, harvesting and hand pulling. The benthic barriers are laid with a barge. Access to the impacted areas is sometimes a challenge, but the laying of barriers, when possible, has proven effective for large infestations. Additionally, LEA ran three harvesting boats this year, each with 3-5 members, that generally work prior to laying the barriers around barrier edges or less accessible or smaller infestations. Each boat and crew costs $1,500 per day, and the work is intense! I’m truly impressed with their efforts and the fact they come back for multiple years, adding much needed expertise and efficiency. LEA coordinates and funds the equipment and equipment maintenance, as well as training and staffing responsibilities, all of which must meet strict safety requirements. It’s not an easy job, and it’s critical in keeping infested lakes in control!

Thanks to LEA, we have a great view of the cost for each infestation. Songo River and its locks have been a main focus due to the volume of boat traffic. LEA first began removing Variable Leaf Milfoil in the Songo River in 2004 and, since then, work has continued with varying rates of success. Right now the river is mostly in control, but at a cost at $40-60,000 per year. In 2017, the Long Lake infestation was caught “early.” Now they’re in maintenance mode, which cost $60,000 last year, and is expected to cost $40-50,000 each year going forward. Warmer water, which we’ve experienced over the last few years, allows Milfoil to spread more easily. Future infestation costs might inflate quickly.

LEA’s milfoil control work is funded through state grants, private foundations, local residents and lake associations. That said, financing is variable. Grants and private foundation contributions can be reduced or eliminated, and organizing lake members to fund a $50,000+ tab per year is a tall order. Due to the high cost of this work, loss of private foundation funding, and lack of significant landowner support, LEA has had to reduce the amount of time spent in some areas – like the heavily infested Sebago Cove. The lake experience, not to mention the property value impact, is incredibly tough. For property values, Maine.gov cites a study showing a 16% decrease in property values after a Milfoil infestation. Lake Arrowhead petitioned and won a 10-20% reduction in their tax values due to the Milfoil infestation in their lake. This is not an insignificant hit.

What are the challenges for Moose Pond?

• Public Boat Ramps. We have two public boat ramps within range of many infested lakes. Keeping boats from bringing in invasive fragments is one of our best first lines of defense. We must continue to fund our boat inspectors and support LEA in their efforts to hire and educate quality staff.  
• Native Milfoil. Moose Pond has an abundance of non-invasive Native Milfoil in select areas. On Long Lake, educating shorefront owners and boaters on identification and reporting methods has helped keep efforts focused on any new growth. Early discovery of plants allows for focused remediation, and reduces the likelihood of rapid spreading. On Moose Pond, we would be challenged to identify Variable Leaf Milfoil early in certain areas, as both Native and Variable have similar feathered leaves and red stems early in the season. Later in the season, Variable Leaf Milfoil will grow far taller than Native Milfoil (15 feet!). By that time the growth and spread from boats and fragments could be extensive. If you are in the North Basin, for example, you can often see Native Milfoil fragments kicked up from boats. Just imagine if that was Variable Leaf Milfoil.
• Warmer Water. While Moose Pond is deeper than many local lakes, we’ve also experienced warmer waters in the past few years. Warmer water results in the faster spread of invasive Variable Leaf Milfoil. Once it’s in…it will spread.
• Size. We’re a beautiful, big lake! However, that means the amount of territory we need to monitor is significant; we have many areas where infestations could thrive. Keeping on top of an infestation is a huge challenge. The Moose Pond Association has 17 Lake Section Captains, who are tasked with scanning for suspicious plans twice each summer. While this is a good effort, we also need many more members of the Moose Pond community to educate themselves and be vigilant in looking for invasive species. The earlier we can identify the issue, the better our chances of controlling or, optimally, eliminating, any infestations. 

I encourage everyone to look at the work LEA has done in controlling Variable Leaf Milfoil in our neighboring lakes. Online, you can see an overview at: mainelakes.org/invasives/milfoil-control/2023milfoil/. If you have the chance to visit and experience the efforts first hand next summer, it’s powerful. 

Keeping invasive plants out of Moose Pond is critical. We will continue to educate our community members and fund LEA boat inspectors. If we ultimately have invasive species enter our lake, early identification, funding and remediation are key.