Peconic River Ludwigia Control Project
DEC and partners have begun herbicide treatments to control an infestation of Ludwigia peploides within the freshwater portion of the Peconic River in Suffolk County. This invasive aquatic plant is known by various common names, including floating water-primrose or floating primrose-willow. Ludwigia peploides grows and spreads rapidly. Infestations can have negative impacts on recreation and tourism as well as severe consequences for the health of aquatic ecosystems and all the plants and animals that live there. It can also spread to other waterbodies via fragments on boats and fishing gear.
Ludwigia peploides fact sheet (PDF)
Background
Ludwigia peploides is an invasive aquatic plant. It was first discovered in New York in 2003 in the Peconic River in the Towns of Brookhaven and Riverhead, Suffolk County. Since that time it has spread throughout the freshwater part of the river. Herbicide treatments to control Ludwigia peploides began in 2022.
Despite more than a decade of hand removal efforts involving more than 5,000 hours of DEC staff and volunteer time, the infestation continues to grow and reduce access to recreation and angling on the river.
Five Year Management Plan
DEC and partners developed the Peconic River Ludwigia peploides Control Project Five-Year Management Plan (2022-2026) . In 2021, a systemic herbicide treatment (a combination of imazamox and florpyrauxifen-benzyl) was piloted successfully in a small treatment area within the Peconic River. Target treatments to control the infestation began in 2022 and are scheduled to occur through 2024.
See the Peconic Ludwigia peploides Control Project Five-Year Management Plan (PDF).
Partners
DEC collaborated with national aquatic invasive species experts, Suffolk County Conservation Advisory Council (CAC), State University of New York at Stony Brook, and US Fish and Wildlife Service to create a Five-Year Management Plan for the infestation of Ludwigia peploides and conducted the 2021 pilot study.
2022-2025 Herbicide Treatment
All permits have been received for 2023 treatment season. Per the Article 15 Aquatic Pesticide Permit requirements, two rounds of riparian landowner notification letters are mailed and shoreline signage notifying of treatment will be posted at all public access points prior treatment each year.
The 2022 herbicide treatment took place on July 27th, 2022. The treatment was a single herbicide application.
The following permits were obtained in order to conduct the 2022 treatment:
- Notice of Intent for coverage under the State Pollution Discharge Elimination System (SPDES) General Permit 0-16-055, Permit ID NYP160548, (pending)
- NYS Environmental Quality Review Act (SEQR) Negative Declaration posted in ENB January 12, 2022,
- NYSDEC Article 24 Freshwater Wetlands Permit - ID 1-4722-02195/00014,
- NYSDEC Article 15 Aquatic Pesticide Permit for ProcellaCOR EC,
- NYSDEC Article 15 Aquatic Pesticide Permit for Clearcast,
- NYSDEC Article 15 Title 27 Wild, Scenic & Recreational Rivers Permit - ID 14722-02195/00015, and
- FIFRA 2(ee) - ID 579281
- Funding for the 2022-2025 project was provided by the Environmental Protection Fund.
Stakeholder Meetings
There are no upcoming stakeholder meetings scheduled at this time. The most recent stakeholder meetings were held virtually on Wednesday, February 16th and Thursday, February 17th, 2022.
Water Sample Results
Surface water samples are collected throughout the Peconic River as per the Article 15 Aquatic Pesticide Permit requirements. Surface water is analyzed for both active ingredients: florpyrauxifen-benzyl (ProcellaCOR EC) and imazamox (Clearcast) to a 1.0 pbb detection limit. This webpage will be updated as water samples results are received. Lab reports will be linked here. Samples will be collected until all sites are non-detect.
2022 Water Sample Results
Clearcast - Day of Treatment Results (PDF)
Clearcast - 24 hours after Treatment Results (PDF)
Clearcast - 1 week after Treatment Results (PDF)
Cleracast - Treatment Results from 08/29/22 (PDF)
ProcellaCOR EC - Day of Treatment Results (PDF)
ProcellaCOR EC - 24 hours after Treatment Results (PDF)
ProcellaCOR EC - 1 week after Treatment Results (PDF)
Resources & Herbicide Use
No adverse impacts of Clearcast (imazamox) and ProcellaCOR (florpyrauxifen-benzyl) on human health have been documented by USEPA (Human Health Benchmarks for Pesticides) (leaves DEC website). No impacts on fish and invertebrates occur at label rates of either herbicide. Native plants could be minimally impacted by the herbicides which is why we are surveying plants both pre- and post-treatment. Additional information can be found on the EPA's webpage about Aquatic Life Benchmarks and Ecological Risk Assessment for Registered Pesticides (leaves DEC website).
Information about the herbicides:
- ProcellaCOR EC NYS Label (leaves DEC website)
- ProcellaCOR EC NYS SLN (leaves DEC website)
- Clearcast NYS Label (leaves DEC website)
- Use of Aquatic Herbicide Imazamox Clearcast in New York State Supplemental Environmental Impact Statement (PDF)
- Florpyrauxifen-benzyl: Environmental Fate and Ecological Risk Assessment USEPA (leaves DEC website)
- Final Supplemental Impact Statement for State of Washington Aquatic Plant and Algae Management (leaves DEC website)
Water Use Restrictions
The 2023 treatment is scheduled for July 2023 and there are no water use restrictions: swimming, boating, and fishing continued as normal. However, please note that the herbicide labels identify a restricted use at concentrations above 1 part per billion (ppb) for irrigation of greenhouse plants. Please see the table below for detailed information regarding water restrictions.
| Product Name | Swimming | Fishing | Livestock Watering | Drinking | Irrigation |
|---|---|---|---|---|---|
| ProcellaCOR EC | No Restrictions | No Restrictions | ≥1 ppb do not use for livestock watering | No Restrictions | ≥1 ppb do not irrigate agricultural crop, greenhouse nursey, or hydroponic plants* (*unless an activated carbon or similar filtration process is utilized prior to water use) |
| Clearcast | No Restrictions | No Restrictions | No Restrictions | No Restrictions | ≥1 ppb do not irrigate greenhouse or nursery plants* (*unless an activated carbon or similar filtration process is utilized prior to water use) |
Contractors
DEC and State University of New York at Stony Brook retained SOLitude Lake Management (NYS applicator license #16506) to conduct the Ludwigia control project in 2021. SOLitude Lake Management performed the herbicide treatment and aquatic plant surveys and mapping. DEC retained Adirondack Research to conduct the pre- and post-treatment aquatic plant surveys for 2022-2024 as well as additional aquatic plant surveys in 2025-2026. DEC retained the Pond and Lake Connection (NYS applicator license # ) to conduct the herbicide treatments and water quality monitoring in 2022-2024.
Community Science
Visitors to the Edwards Avenue Boat Launch in Calverton are encouraged to take photos of the pilot project site and submit them to Chronolog. A device mounted near the launch will allow visitors to take a series of time lapse photos that we will us to track the impacts of the treatment on the Ludwigia peploides in Browns Bog. For more information about the Chronolog project, visit its website (leaves DEC website).
Contact Information
Please contact us if you have any questions or need additional information.
Local Contact:
Heidi O'Riordan, Fisheries Manager, NYS DEC, Region 1
50 Circle Road
Stony Brook, NY 11790-3409
[email protected], 631-444-0280
Bureau of Invasive Species and Ecosystem Health:
Cathy McGlynn, Aquatic Invasive Species Coordinator, NYS DEC,
625 Broadway, 5th Floor
Albany, NY 12233-4253
[email protected], 518-402-9425
Croton River Hydrilla Control Project
Background
Hydrilla was discovered in the Croton River in October 2013 and later found in Croton Bay during a site survey in 2014 (Towns of Cortlandt and Ossining, Westchester County, NY). This survey also revealed that hydrilla is well-established in the Croton River and the New Croton Reservoir. While hydrilla remains in the Croton River and Bay, it threatens habitats in the Hudson River and its tributaries. Fortunately, the results of aquatic plant surveys conducted in 2017-2021 indicate that hydrilla has not yet spread outside of the Croton River and New Croton Reservoir. Public meetings have been held annually to inform the public of the infestation and address concerns about management plans.
Five Year Management Plan and Annual Project Updates
The Five -Year Management Plan defines the project's goals and is used to guide management decisions. This plan was developed through collaboration with national hydrilla experts, the NYC Department of Environmental Protection (DEP), the NYS Department of Health Bureau of Water, DEC staff, Village of Croton on Hudson, and environmental stakeholders including Lower Hudson PRISM, Scenic Hudson, Riverkeeper, Saw Mill River Audubon, and Hudson River Sloop Clearwater.
- Five Year Management Plan (PDF) (updated June 2019)
- 2021 Annual Report (PDF)
Contact Information
Please contact us with any questions or if you need additional information.
NYSDEC Bureau of Invasive Species and Ecosystem Health
Cathy McGlynn, Aquatic Invasive Species Coordinator
625 Broadway, Albany NY 12233
[email protected]
518-402-9425
