Dear NEANS Panelists and ANS friends, Please post to this page your Roundtable updates so that those not at the meeting will be able to read them and to keep the meeting summaries concise. Thank you. Michele L. Tremblay
Northeast Aquatic Nuisance Species Panel Forum
published by and for the Northeast Aquatic Nuisance Species Panel
Dear NEANS Panelists and ANS friends, Please post to this page your Roundtable updates so that those not at the meeting will be able to read them and to keep the meeting summaries concise. Thank you. Michele L. Tremblay
During the summer of 2023, we added three new waterbodies to the infested list, with a new variable milfoil infestation, brittle naiad infestation, and one curly-leaf pondweed infestation. In general, it seems like brittle naiad has been on the move in recent years, popping up in at least one or two new waterbodies each season, spreading more quickly than other aquatic invasive plants in the state.
We also confirmed spiny water flea in Lake Winnipesaukee, after eight years of monitoring for it (Winnipesaukee previously only had variable milfoil in it for invasives). It was found in several locations in the lake, with evidence of both asexual and sexual reproduction occurring. We also just confirmed a population in Lake Winnisquam, which is downstream of Lake Winnipesaukee. Population densities were still low in September 2023, and continued monitoring will be conducted to document population growth, expansion, and impacts to the lake food web.
Aquatic invasive plant management activities generally include a mix of herbicide and non-chemical means of control, including diving and diver-assisted suction harvesting (DASH). Management is integrated, and adaptive based on site-specific characteristics.
In 2023, 21 herbicide treatments were performed (mostly for variable milfoil control, but also for fanwort, brittle naiad, curly-leaf pondweed, and Eurasian water milfoil). Simple diving and hand harvesting was performed on four waterbodies, and DASH was conducted on 39 waterbodies.
Funding for the New Hampshire Exotic Species Program is in jeopardy, because of how fees are collected in the state. Program revenues are derived from a fee associated with boat registrations, which has been determined to be an illegal collection of fees under federal regulations (even though these fees have been in place for 30+ years). A federal audit was conducted that identified the infraction, so alternative funding mechanisms are going to be sought in this upcoming legislative session. Funding collected as part of boat registration fees can only be used for purposes of supporting a boat registration program, not other programs. Luckily, existing program funding mechanisms will stay in place until new legislation is enacted. Pending outcomes of the legislative fix, the program could continue as it has been, or it (grants, monitoring, staffing, and all other program elements) could be eliminated due to lack of program funding. Several partners are working to maintain the funding and identify other sources of funding for the program.
With significant time and effort put into prevention and early detection efforts for the last decade plus, we saw a reductio in the rate of spread of aquatic invasive species in New Hampshire for many years. While infestations still did happen, there were fewer new ones each year, and those that did occur were found quickly by vigilant monitors, when plants were still sparse and low density, for the most part.
Unfortunately, in the last couple of years the rate of infestation seems to be picking up again, and the infestations, when first found, are larger and more expansive, as though they were missed for a few years by residents and volunteers.
I am not sure if this is reflective of a changing of the guard when it comes to local volunteers keeping an eye on waterbodies, a general increase in boating from the pandemic years, spreading infestations more quickly, or a mix of the two (or something else entirely). Even waterbodies that have a two-tiered structure of protection (Lake Hosts at public access educating boaters) and Weed Watchers (monitoring for new infestations in waterbodies) have seen problematic infestations occur.
We will continue to increase outreach and education activities to target more transient boater groups and volunteer monitoring groups, but the trend is discouraging, and needs to be turned around!
What MassDEP has done since Spring 2023:
• Reviewed and issued 479 Chemical Application Licenses and amendments for invasive species management in Massachusetts. In addition, 401 Water Quality Certifications were also issued to individuals/towns, providing conditions with best management practices on waterbodies with invasive species to prevent their further spread to other waterbodies; a 401 WQC (ID: 23-WW08-0014-APP) was issued specifically for nuisance plant hydro-raking at Brown’s Pond to the Town of Peabody in October 2023
• Assessing MA waterbodies with invasive species infestation and add them to the CWA 303d List and 303b Report
• Continuous technical supports to communities on invasive species prevention, detection, and management
• David Wong did a presentation: Freshwater Invasive Species in Massachusetts in the Face of Climate Change. Society of Wetland Scientists New England Annual Chapter Conference. Stow, MA. October 6, 2023.
Thank you, David. Congratulations on your book. It’s really beautiful and I hope that it becomes a standard for academia and managers.
Connecticut Update
Connecticut River hydrilla dominated Connecticut’s aquatic plant management concerns in 2023. The unique strain called Clade C, infests the river from Agawam, MA southward to within a few miles of Long Island Sound. Led by the United States Army Corps of Engineers (USACE), studies began on documenting the hydrilla’s phenology and the presence of state-listed species at several sites where herbicide tests may be performed in 2024. In addition, rhodamine dye tests were performed at the sites to document water movement and retention time. A second diquat treatment of the Clade C hydrilla in Wethersfield Cove occurred in July with apparent success.
Unfortunately, Clade C hydrilla was documented by The Connecticut Agricultural Experiment Station (CAES) Office of Aquatic Invasive Species (OAIS) in four lakes, with an additional lake waiting on genetic confirmation. This confirms fears that non-riverine aquatic ecosystems are in peril. Many of these populations were adjacent to public boat ramps. The East Twin Lake site received a high-dose ProcellaCOR treatment, and its efficacy is being evaluated. Collaborative management research between CAES OAIS, USACE, and others in waterbodies outside the Connecticut River watershed is being discussed.
Grass carp have been introduced into several larger Connecticut lakes to control nuisance vegetation. These lakes have exhibited depletion of nearly all aquatic vegetation after five to seven years. In the case of Candlewood Lake, Connecticut’s largest lake, the vegetation loss was extremely rapid and occurred over the 2021/2022 winter. To reduce grass carp overgrazing, The Connecticut Department of Department of Energy and Environmental Protection (CT DEEP) began removing some of the grass carp and now allows angling by permit.
CAES OAIS has confirmed inflated bladderwort (Utricularia inflata) is now in many lakes and is replacing native bladderworts. The plant has not yet become a major nuisance but monitoring its expansion throughout the state is needed.
CT DEEP is expected to be issuing requests for proposals for the fourth round of grant funding through the Aquatic Invasive Species Grant Program this fall. Future funding for the grants may be altered as mandatory payment through boat registrations is no longer allowed. CT DEEP/UCONN is expected to be hiring an Invasive Aquatic Plant Coordinator by Spring.
CAES OAIS has completed staff hiring. Riley Doherty was brought on as a research technician and Dr. Jeremiah Foley was hired as an assistant scientist. They joined Summer Stebbins and Greg Bugbee.
Terrible news about Utrucularia inflata. It is such an important native plant.