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Eurasian Watermilfoil information from Barry Cahoon, JPA Response Coordinator, 9/18/2024
I suspect most, if not all Joe’s Pond Association (JPA) members, are by now aware of the discovery in Joe's Pond of established populations of the invasive aquatic plant known as Eurasian Watermilfoil (EWM).
For those of you not already familiar with EWM, it is an incredibly aggressive non-native species that grows rapidly, spreads readily, and can fill and clog the water column throughout the shallow waters of the lake (the littoral zone) with a dense mass of vegetation precluding most human uses of the water potentially even passage by motorized watercraft.
EWM can spread by rhizome (new plants sprouting from roots spreading in the lake bottom), by seed, but most often and most insidiously by plant fragmentation. Where EWM has grown into mature plants reaching near or to the water surface, it is vulnerable to breaking into fragments, most commonly by passing watercraft which then can drift anywhere on the lake, sink to the bottom and take root to establish a new population. Fragmentation and spread can also occur when attempting to remove EWM either by hand or mechanically.
Joes Pond is classified as a mesotrophic lake (bordering on eutrophic) meaning it is nutrient rich. As such, Joe’s Pond is an ideal aquatic plant nursery in which plants can grow dense and fast. Joe’s Pond also has a relatively extensive littoral zone as a percentage of its total surface area. The third attachment above shows the extensive littoral area on Joe's Pond suitable for EWM infestation.
One positive aspect of Joe's Pond is that it supports a robust population of native plant species which can help prevent the establishment of EWM in those areas. This is why it is recommended by the state to leave existing native plant populations intact.
That Joe’s Pond supports extensive plant growth has been exacerbated by the recent floods which have introduced tremendous volumes of fine sediment into the pond from every small and large tributary. You likely remember how turbid the pond remained for weeks after the July flood until this fine sediment settled to the bottom. Flood generated sediment deposition typically is high in phosphorus which is an essential plant food fueling aggressive growth when in high concentrations.
So we have a perfect storm here for EWM to thrive.
It is the opinion of not only the invasive species professionals from the VT Watershed Management Division, but also of the JPA members who have been directly involved in the EWM containment activities to date, that it is an unrealistic expectation we will be able to totally eradicate the current infestation. It has been established for too long (up to 2 years or more) and has spread too widely for complete elimination to be realistically feasible. That's not to say that achieving complete eradication is impossible, only that it's not likely. We don't want to inhibit an effective response to this threat be setting unachievable goals.
If the members of the JPA (the official stewards of Joe's Pond) accept this premise, then we are left with the approach of containing and limiting the infestation at manageable levels; potentially in perpetuity.
Let me state this again: I believe this battle with EWM will not likely be over within any existing member's lifetime. I hope I'm wrong but I'm not all that hopeful.
Manageable in this context means logistically, physically, and financially within the resources of the JPA along with whatever financial and technical assistance we can garner from outside sources.
Even at this scaled back objective, i.e. management vs. eradication; it will take everything we've got to achieve it; an extreme and, I might say, valiant effort.
Speaking of the resources available to the JPA: Our greatest and most valuable resource is the membership. The extent of success in our efforts to contain EWM is directly proportional to the level of engagement and involvement of you the members.
We have a small group of members who, at the JPA meeting on 09/14, signed up as volunteers to conduct surveys along their shorelines, assist with writing grant applications, and other tasks. We even have a small cadre of divers and snorkelers who have signed up.
But we need more. Many more.
If you wish to see the values you have enjoyed throughout your time on this beautiful lake preserved not just for the rest of your life but also for your kids, grandkids and beyond, then you need to get actively involved.
The state's active emergency response effort may end Friday 09/20. This has consisted of 2 boat surveys of the littoral zone, and, after Friday, 3 sessions of hand pulling plants in the identified areas of EWM establishment just off the shoreline along Sandy Beach Road.
I suspect, after Friday, the state invasive species professionals, led by Kim Jensen, who made the presentation at the JPA meeting on 08/31, will recommend that JPA place a benthic barrier (basically a big sheet of plastic) over the dense patch of EWM where the bulk of the hand pulling has been focused. This is due to the large number of small young plants and extensive root systems that have already developed there. This phase will entirely be the JPA's responsibility.
We have submitted a grant application to the state to help pay for the bottom barrier and installation. But it has not been determined whether we will be able to mobilize an adequate dive crew for installation or have the window of opportunity to get the barrier in place this fall. Depending on Kim's recommendation, after Friday we may begin pursuing installation of the barrier.
But more importantly, what needs to be on every member's consciousness is the need to locate, identify, and mark any additional established EWM populations as soon as possible. This point cannot be overemphasized. We will never achieve our goal of containing the EWM infestation at a manageable level if we do not find the existing plants ASAP.
For example, Alicia and I found another floating fragment by our shoreline on Old Homestead Road this past Sunday. That is the third we have found there. However, we have thoroughly searched the area along and out from our shoreline and seen none growing in the area.
It seems evident that there may be a patch of EWM somewhere along the shoreline east of us that motorboats are passing through and chopping up. Each discovery has occurred when the wind was from that direction. Jim Bernotas has stepped up and offered to dive this coming Saturday 09/21 and search the shoreline along at least a portion of Old Homestead Road above the upper narrows. Boaters please beware of this possible dive operation on Saturday in this area and steer clear.
But if there is milfoil drifting around the lake, there could be established populations anywhere and simply go undetected by the state's boat-based visual surveys especially if there are young plants growing close to the bottom.
It's not too late to get in the water and wade or search from a canoe or kayak. Alicia and I have been in and on the water searching for the last few days. But the window of opportunity will be closing fast. So get out there if at all possible.
If you strongly suspect you have found milfoil, mark it with a buoy. It was suggested to me by a member to use a 12-18" piece of a brightly colored styrofoam swim noodle. Tie a piece of twine securely around it and a brick for an anchor. This might work better and be more visible than a soda bottle. Report your findings to me.
Do not attempt to pull up the milfoil beyond grabbing a fragment to examine more closely to make a positive ID. Leave the hand pulling to the trained divers from either the state or JPA volunteers or JPA contractors. By next season we hope to have a cadre of JPA divers/snorkelers trained in EWM hand pulling. See the identification resources contained in the attachments to this email and on the JPA website.
Please talk to your neighbors and friends on the lake and encourage them to get involved. We cannot have too many volunteers.
If you can be added to the volunteer list, please email me. Note what you can offer. Plant surveys, diving, snorkeling, etc.
Also, keep track of the hours you spend surveying and searching for EWM or anything else EWM response related. This data is important to support any JPA grant applications to the state.
I also hope to have a digital map, possibly interactive, or some other system to help track where surveys have been performed by JPA members and at what level, i.e. visual from a boat, scuba dive, etc.
Another suggestion that has been made is to divide the lake shoreline into sections and designate a "Section Coordinator" who will recruit and encourage neighbors to raise their awareness and survey the water along and out from their shoreline. The Section Coordinator would also track the survey and monitoring efforts conducted in their designated area. If any volunteers are interested in adopting this role or know someone on the lake who does, please let me know.
For the foreseeable future, boaters are encouraged to develop the habit of staying outside the littoral zone (15 feet of water or less) except to access or egress your dock. This will reduce the chances of fragmentation and spread of any established EWM which, again, is its primary mode of propagation in new areas.
It is anticipated that in the spring of 2025 the state will conduct a Vermont Invasive Patrollers (VIP) workshop hopefully on Joe's Pond. There is a link to the VIP manual on the "Invasive Species" page of the JPA website.
Two PDF files above and a link on the JPA website on the "Invasive Species" page to "A Key to Common VT Aquatic Species" (page 20 of the document) will assist members in positive identification of EWM and contrast with other aquatic species.
A number of other EWM related files will soon be added to the JPA website. Please revisit the site whenever you have the opportunity.
Thanks for your interest, your attention, your vigilance, your participation, and especially, your love for Joe's Pond.
For Joe’s Pond
Barry Cahoon, JPA EWM Response Coordinator
802-535-0049
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