Home » Hudson River Aquatic Invasive Species Task Force

Task Force:

Hudson River Aquatic Invasive Species


The Hudson River is an expansive corridor that provides valuable habitat and migration pathways for native species across the Northeast US and beyond, as well as a myriad of ecosystem services for local (human) communities. It has been well established that invasive species pose a key threat to the ecological and economic resources that the River provides 

The Hudson River Aquatic Invasive Species Task Force brings together state, nonprofit, and community partners to coordinate invasive species monitoring and control in this important watershed. At present, our geographic scope includes the Hudson River and its tributaries. 

Shared Priorities


Because early detection and rapid response are much more efficient and cost-effective than trying to control a widespread infestation, we consider emerging species to be high-priority for control.

The species tables below show PRISM tier rankings, NYS tier ranking, morphology, NYS risk assessment, monitoring methods, and management methods. Click here to view or download as a spreadsheet.



Scientific NameCommon NameCapital Region Tier RankLower Hudson Tier RankNYS Tier RankMorphologyNYS Risk AssessmentMonitoringManagement
Aldrovanda vesiculosaWaterwheel1a12floatingNo assessment availableVisual, rake toss No effective control method known.
Alternanthera philoxeroidesAlligatorweed1c11bemergent, floatingNo assessment availableVisual, rake toss Physical management is not effective. A biocontrol exists but is not commercially available. Several herbicide treatment options are available.
Butomus umbellatusFlowering rush22untieredemergentMVisualSmall infestations can be carefully dug up, taking care to leave no bulbils behind. Herbicides may be effective when applied during summer when waters are calm or during a dry spell.
Cabomba carolinianaCarolina fanwort1a23submerged with floating/emergent flowersHVisual, rake toss Mechanical removal, water level manipulation, and chemicals have been tried in the Northeast with limited success.
Egeria densaBrazilian elodea1a22submergedHVisual, rake toss No effective control method known.
Pontederia crassipesWater hyacinth522floatingNotAssessedVisualManual removal may be effective for small populations. A mechanical harvester or herbicides should be used for larger populations. There are some biocontrol options as well.
Hottonia palustriswater violetnot rankednot rankednot rankedsubmerged with emergent flowersNo assessment availableVisual, rake toss No effective control method known; no resources found.
Hydrilla verticillataHydrilla1a22submergedVHVisual, rake toss Mechanical removal, physical habitat manipulation, herbicides, and biological agents have been used in the U.S. Herbicides are used in the Croton River.
Hydrocharis morsus-ranaeEuropean frogbit224floatingVHVisual, rake toss Chemical control has been effective on the Great Lakes. Physical removal may provide temporary control.
Ludwigia adscendensfloating water primrosenot ranked11bemergent, floatingNo assessment availableVisualNo effective control method known; no resources found. Control methods that are successful on Ludwigia peploides may succeed when applied to this species as well.
Ludwigia grandifloraLarge flower primrose willow1b2not rankedemergent, floatingVHVisualNo effective control method known; no resources found. Control methods that are successful on Ludwigia peploides may succeed when applied to this species as well.
Ludwigia hexapetalasix petal water primrosenot rankednot rankednot rankedemergent, floatingNo assessment availableVisualNo effective control method known; no resources found. Control methods that are successful on Ludwigia peploides may succeed when applied to this species as well.
Ludwigia peploidesFloating primrose willow1b12emergent, floatingVHVisualManual control is not advisable as it can easily disperse fragments. Chemical control is being piloted on the Peconic River.
Marsilea quadrifoliaEuropean water fern52untieredslightly submerged, floating, or emergent. Can grow in wet terrestrial habitatUknownVisual, rake toss No effective control method known. Chemical treatment with bensulfuron methyl has been successfully used in Japan.
Murdannia keisakMarsh dewflower11aemergentHVisualRetrieving data. Wait a few seconds and try to cut or copy again.
Myriophyllum aquaticumParrot feather1a12submerged, emergentHVisual, rake toss Physical and chemical control methods have been tried with limited success.
Myriophyllum spicatumEurasian watermilfoil444submerged, floatingVHVisual, rake toss No effective control method known.
Nasturtium officinaleWatercress33untieredemergent, floatingMVisual, rake toss Small populations may be physically removed, taking care to remove all parts of the plant. Herbicides have been effective, but only on plants above the waterline.
Nelumbo nuciferaSacred lotus/Pink lotus1b1untieredsubmerged with floating leaves and emergent flowersMVisualRetrieving data. Wait a few seconds and try to cut or copy again.
Nitellopsis obtusaStarry stonewort214submergedNo assessment availableVisual, rake toss Physical removal is not likely to work. Application of algaecide may be effective for low-growing populations; however, taller populations will absorb the herbicide at the top of the plants, killing the top but leaving the bottom alive.
Nymphoides peltataYellow floating heart223submerged with floating leaves and emergent flowersHVisualRepeated cutting may be effective. Raking the plant out when the sediment is loose may be effective, if care is taken to remove all parts of the plant. Some aquatic herbicides containing glyphosate have been effective after several treatments.
Pistia stratiotesWater lettuce512floatingNAVisualNo effective control method known.
Stratiotes aloides L.Water soldiers1c11asubmerged, emergentNAVisual, rake toss Shade cloth enclosures over the plant has shown to work. The efficacy of mechanical harvesting has not been evaluated. Diquat herbicides can be effective, but efficacy decreases in deep, fast-flowing, or turbid water.
Trapa bispinosaTwo Horned trapanot rankednot rankednot rankedfloatingNo assessment availableVisualFoliar and water column herbicide applications prior to fruit production can be successful. Hand-pulling is effective for small populations, if care is taken to remove the entire plant. Mechanical harvesting may be used for larger populations. A biological control agent is being investigated. Water level drawdowns before fruit production may be effective.
Trapa natansWater chestnut434floatingVHVisualFoliar and water column herbicide applications prior to fruit production can be successful. Hand-pulling is effective for small populations, if care is taken to remove the entire plant. Mechanical harvesting may be used for larger populations. A biological control agent is being investigated. Water level drawdowns before fruit production may be effective.



Scientific NameCommon NameCapital Region Tier RankLower Hudson Tier RankNYS Tier RankNYS Risk AssessmentMonitoringManagement
Bithynia tentaculataMud bithynia223NAeDNA, visual surveys in shallow water, dip netting in deeper waterNo effective control method known.
Bythotrephes longimanusSpiny waterflea213Not assessedeDNA, zooplankton nets with a mesh size of 250 microns.No effective control method known.
Carcinus maenasGreen crab1a1untieredNAeDNA, trappingTrapping and removal may be impactful in small aquatic systems. Poison bates exist but are not size-selective. Management of native populations for biotic pressure has been impactful.
Cercopagis pengoiFishhook waterflea1b13VHeDNA, zooplankton nets with a mesh size of 250 microns.No effective control method known.
Channa argusNorthern snakehead1a12HeDNAPhysical removal may be impactful for small infestations, but it is difficult to prove success. Chemical management options are not selective.
Corbicula flumineaAsian clam423HeDNAChemical and mechanical methods may be used in closed systems such as power plants, but management is prohibitively complex in natural aquatic systems.
Ctenopharyngodon idellaGrass carpnot ranked2untieredMeDNA, electrofishing, trappingIncreased harvest, electrofishing, trapping. Introduction of sterile males or monosex tetraploids.
Dreissena rostriformus bugensisQuagga mussel213VHeDNANo effective control method known.
Eriocheir sinensisChinese mitten crab223MeDNA, trappingNo effective control method known.
Gymnocelphalus cernuusEurasian ruffe1not rankedNot assessedeDNAno effective control method known. Chemical treatments may be available, but they are not selective.
Hemigrapsus sanguineusAsian shore crab1a23VHeDNANo effective control method known.
Hemimysis anomalaBloody red shrimp323HeDNA, Trapping with plankton nets.No effective control method known.
Hypophthalmichthys harmandiLargescale silver carpnot ranked1not rankedMeDNANo effective control method known; no resources found.
Hypophthalmichthys molitrixSilver carpnot ranked11HeDNANo effective control method known. Barriers may be used to prevent further spread.
Hypophthalmichthys nobilisBighead carpnot ranked1"buffer"MeDNAno effective control method known, but barriers may be used to prevent further spread.
Misgurnus anguillicaudatusOriental weatherfish1a23HeDNANo effective control method known.
Neogobius menalostomusRound goby1a14HeDNA, trappingFish pesticides, physical barriers, and bioacoustic or pheromone traps may be effective for managing and/or preventing further spread.
Potamopyrgus antipodarumNew Zealand mud snail1a12HeeDNAChemical options may be available. A biological control is being investigated.
Procambarus clarkiaRed swamp crayfish1b12Not assessedeDNAControl methods have been proposed but none have proven effective yet.
Procambarus virginalisMarbled crayfishN/AN/AN/ANot assessedeDNANo effective control method known.
Proterorhinus semilunaris (P. marmoratus)Tubenose gobynot ranked1untieredMeDNA, trappingNo effective control method known, but acoustic deterrents and barriers may prevent further spread.
Scardinius erythrophthalmusRudd32untieredMeDNATrapping with fine-mesh monofilament gill nets can reduce the population size temporarily, but this is not a long-term solution. Some chemical control methods are available but are not selective.
Tinca tincaTench1a12HeDNANo effective control method known.


In addition to prioritizing control of early emerging invasive species wherever they are found in the Hudson River watershed, we also aim to protect specific places within the watershed that provide exceptional ecological resources and ecosystem services. We developed a framework to determine these priority places for aquatic invasive species monitoring and control.

In this framework, streams, lakes, ponds, tidal wetlands, and other significant habitats are given points for various criteria that influence their conservation value. Top-scoring water bodies are selected as priority monitoring areas.

Click here to view our interactive site prioritization tool.

Click here to read more about our prioritization methods. 


Upcoming Events

Emerging Invasive Species Threats in the Hudson River- a new webinar series

We have started an exciting new webinar series highlighting the latest research and updates on new aquatic invasive species in the Hudson River Watershed. Stay tuned for upcoming events, and in the meantime check out recordings of past webinars below. 


Webinar Recordings

Hydrilla in the Croton River: Containing an Emerging Invasive Species

November 30 2022

With Nicole White, NYSDEC and Little Bear Environmental Consulting LLT

Hydrilla (Hydrilla verticiliata), a submerged noxious weed that can grow up to 30 ft in length and form dense mats in lakes and rivers, is considered one of the world’s most invasive aquatic plants. Join us to learn about hydrilla’s impacts on our ecosystems and wildlife, as well as a multi-year effort to control the plant in the Croton River and prevent its spread to the larger Hudson River watershed.

Water Chestnut on the Hudson River: Impacts, Management, and Preventing the Next Invasion

October 11 2022

With Dr. Steve Pearson, NYSDEC; Kelly McKeon, MIT/WHOI; and Lynde Dodd, USACE

Water Chestnut (Trapa natans) is a widespread invasive plant that floats on top of lakes and slow-moving rivers. Learn how water chestnut impacts the Hudson River and the ability of its marshes to adapt to climate change; how researchers study water chestnut and prioritize areas for control; and how all of these dynamics may shift in response to a new species of water chestnut, T. bispinosa, that has emerged in the mid-Atlantic US. 

Round Goby on the Hudson River: Status, Implications, and Preventing the Next Invasion

September 21 2022

With Scott George, USGS; Rich Pendleton, NYSDEC HREP; and Dr. Stuart Findlay, Cary IES   

The round goby, Neogobius melanostomus, an aggressive fish that inhabits the bottoms of lakes and rivers, has been classified as an invasive species in several parts of the world including North America, parts of Europe, and the Baltic Sea. Since its arrival in the Great Lakes in the ‘90s, researchers have watched with trepidation as the fish’s range expanded eastward. In 2021, the round goby was observed for the first time in the Hudson River and has spread rapidly since then. This webinar covers the latest research on the round goby’s impact in this new river system, implications for the biology of the Hudson River, and large-scale efforts to prevent future invasive species spread to new watersheds. 


Best Management practices




The searchable directory of partners and projects below is intended to help connect invasive species researchers and stewards with similar interests.

NameTitleOrganizationLocationGeographic Scope of WorkDescription of work and interestsSpecies
Lindsay CharlopEstuary Training Program CoordinatorHudson River National Estuarine Research ReserveStaatsburg, NYfocused on the Hudson River EstuaryCoordinating and facilitating the Hudson River Aquatic Invasive Species Task ForceAs needed
Heather GierloffReserve Manager, Marine habitat manager for regions 3 and 4Hudson River National Estuarine Research ReserveStaatsburg, NYHudson River and focus on four intertidal component sites of the Research Reserve, Stockport Flats, Tivoli Bays, Iona Island and Piermont Marsh.
The Research Reserve is fostering the connection between the research community and the stewardship community. To better understand how aquatic invasive species impact the Hudson River aquatic habitats and how to prioritize actions to minimize the impacts.We focus on protecting native species such as Vallisneria americana in Submerged Aquatic Vegetation (SAV) beds.
Sarah FernaldResearch CoordinatorNYSDEC and Hudson River National Estuarine Research ReserveStaatsburg, NYHudson River Estuary; specifically the HRNERR component sites, which are Stockport Flats, Tivoli Bays, Iona Island, and Piermont MarshI conduct baseline monitoring of estuarine habitats, specifically tidal wetlands and submerged aquatic vegetation (SAV). My work in invasive species involves mapping the cover and change over time in plant communities, focusing on the more widespread invasive plants (Trapa natans Phragmites australis, Myriophyllum spicatum) to study how they impact ecosystem functions and the resilience of these habitats to projected climate change stressors.I currently work with Trapa natans, Phragmites australis, Myriophyllum spicatum. I was also involved in the initial detection of the Chinese Mitten Crab (Eriocheir sinensis) in the Hudson RIver Estuary.
Catherine McGlynnAquatic Invasive Species Program CoordinatorNYSDECAlbany, NYNew York State and Northeast/Mid-Atlantic/Great Lakes Regions- Monitor and Survey habitat suitable for hydrilla;
- Assist with Croton River hydrilla control Project
- Water chestnut surveys/removal
- Grass Carp detection and distribution
- LI-Metro Aquatic OIT Symposium
hydrilla, Brazilian elodea, curly leaf pond weed, Eurasian watermilfoil, Ludwigia, European frogbit, fanwort, parrot's feather, water chestnut, Northern snakehead, grass carp, zebra mussel, quagga mussel, Asian clams, round goby, Chinese mitten crab, starry stonewort
Steven PearsonResearch BiologistNYSDECAlbany, NYNew York StateWorking to determine aquatic invasive species distribution, abundance, life history and management strategies.Flora and fauna
Nicole WhiteCroton Hydrilla Control Project ManagerNYSDEC Invasive Species Coordination SectionNYSDEC Region 3New York State- Design of control projects and management plans for various aquatic invasive plant species in rivers, lakes, ponds in the Hudson River watershed
- Field survey and data analysis for native and aquatic plant species abundance over time in HR watershed
- Design of manual and chemical control projects for AIS
- Work to facilitate close communication between NYSDEC ISCS, Lower Hudson PRISM, municipalities, and other regional partners to prioritize AIS early detection and rapid response
- Environmental permitting for AIS projects
Hydrilla (Hydrilla verticillata), Floating primrose-willow (Ludwigia peploides), Water chestnut (Trapa natans), European frogbit (Hydrocharis morsus-ranae), Fanwort (Cabomba caroliniana), Eurasian watermilfoil (Myriophyllum spicatum), Brazilian elodea (Egeria densa), Brittle naiad (Najas minor), Curly leaf pondweed (Potamogeton crispus), Northern Snakehead (Channa argus), Rusty crayfish (Orconectes rusticus)
Dan SmithLand Stewardship CoordinatorScenic HudsonPoughkeepsie, NYAlbany and Renselear Counties to Rockland and Westchester. Greater focus on Columbia, Dutchess, Greene, and Ulster Counties.To this point our focus has been on terrestrial invasive species. However, we manage a number of river accesses and properties with tributaries to the Hudson and are interested in engaging with aquatic invasives more in the future.Water chestnut (currently).
Dan ShapleyCo-Director of Science and PatrolRiverkeeperOssining, NYHudson River Watershed and NYC Watershed- Impacts on native biota
- Impacts on water quality
- Impacts on drinking water quality
- Impacts on habitat/ecology
David DeckerLand StewardConstitution Marsh Audubon CenterGarrison, NYWe manage two Hudson River tidal marshes: Constitution Marsh and the RamsHorn-Livingston Marsh located in Catskill, NY in partnership with Scenic Hudson.We work to preserve marsh habitat from the impacts of invasive species in order to protect the vulnerable wildlife species that use the marshes along the Hudson River. Our main project is a mechanical control project for Phragmites australis at Constitution MarshPhragmites, water chestnut
Lynde DoddUS Army Research and Development CenterLewisville, TXUSACE Projects including reservoirs, rivers, wetlands, and other navigational authorities.My research focus: invasion and restoration ecology of freshwater macrophytes. I currently work with a number of stakeholders including USACE, state, local, and NGOs in applied research to learn more about and manage invasive aquatic plant species to facilitate sustainable and resilience aquatic vegetation communities.
water chestnut, hydrilla
Matt BrinckaInvasive Species BiologistNYS OPRHPAlbany, NYNew York StateInvasive Species Biologist working for New York State Parks; Provide guidance and support on all invasive species, both terrestrial and aquatic; Work closely with partners on Statewide and Regional initiatives involving invasive speciesTypically new or emerging threats
Brian DeGasperisRestoration BiologistHudson River National Estuarine Research ReserveStaatsburg, NYHudson River (Westchester to Troy)- Survey and assessment
- Early detection and prevention
- Management and control
- Impacts on native species and ecosystem processes
- Restoration of native habitat
Water chestnut, hydrilla, brittle naiad, curly leaf pondweed, milfoil, Phragmites, purple loosestrife, yellow iris, zebra mussels, Asian clam, goldfish, common carp
Daniel MillerHabitat Restoration CoordinatorNYSDEC Hudson River Estuary ProgramStaatsburg, NYHudson RiverHudson River habitat restoration including shorelines, shallows and intertidal areas. Manage small scale Phragmites management efforts.Phragmites
Scott CuppettWatershed Program ManagerHudson River Estuary ProgramNew Paltz, NYHudson watershed between Troy and NYCWork involved instream and streamside restoration, such as dam removal, riparian vegetation restoration, and replacing culverts. Invasives in these disturbed areas can host aquatic and terrestrial/aquatic transition zones. Implementing project can also lead to newly disturbed areas for invasives to occupy. How to manage them during and after restoration can be a challenge.Until now, its primarily been Japanese knotweed, water chestnut, and phragmities, although future barrier mitigation projects could be impacted by not wanting certain aquatics to occupy unavailable upstream habitat, such as brown Ttrout, or Chinese mitten crab.
Rich PendletonNYSDECNew Paltz, NYHudson River, Troy to George Washington BridgeLong-term fish monitoringRound goby
Gregg KenneyMarine BiologistNYSDEC New Paltz, NYHudson River tidal estuary and tributariesWe manage the migratory fish in the Hudson. Our AIS priority is to prevent future invasions of aquatic species, particularly via swimming from connected watersheds.Emerging aquatic invasive species
Jessica KuonenHudson Estuary Resilience SpecialistNew York Sea GrantKingston, NYHudson River Estuary (Troy to Manhattan)In my work, I serve waterfront communities, boaters, and water-based businesses on a variety of issues. There is interest from these groups in keeping up-to-date with the latest science and best management practices for aquatic invasive species. NYSG can play a role in connecting these groups to the proper resources.None directly, but I hear from my stakeholders about water chestnut the most.
Scott GeorgeBiologistU.S. Geological SurveyTroy, NYPrimarily New York, but able to work throughout the United States.I have studied the expansion of round goby in central and eastern New York since 2016. I continue to conduct this research on the Mohawk River and am initiating a new phase of monitoring in the Champlain Canal. I am also collaborating with researchers studying round goby in the Hudson River estuary.Round goby
Steve YoungChief BotanistNYNHPAlbany, NYNew York StateWe inventory and protect rare aquatic species in NY and invasive species are a main threat to their viability. We would like to detect invasive aquatic species before they become a problem in the Hudson River and lend our botanical expertise to help control established ones.Aquatic Invasive Plant species, across New York State.
Andrew DanglerBiologist- Senior Project ManagerU.S. Army Corps of EngineersWartervliet, NYNYSDEC Regions 4-5I currently review applications for Department of the Army permits pursuant to Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act. Controlling the spread of invasive species and limiting their encroachment into mitigation areas are factored into the application review and approval process.Primarily water chestnut
Michael SpadaAquatic EcologistNYC Department of Environmental ProtectionKingston, NYDelaware, Greene, Putnam, Schoharie, Ulster and Westchester countiesAquatic invasive species are of interest to me since I focused on zebra mussels for my Masters of Science degree, so beyond my intrinsic interest in AIS there are practical reasons for my interest. Several of NYC's drinking water reservoirs are in relatively close proximity to the Hudson River, and as such could be a potential source for infestation of NYC's water supply. Lastly, NYC has pump facilities on the Hudson River to augment the water supply during times of drought emergency.Zebra and quagga mussels, Cercopagis pengoi, Corbicula fluminea, Orconectes rusticus, hydrilla (ancillary)
Mark SolanSection ChiefNew York State Department of Environmental Conservation; Bureau of Pesticide Management
Schenectady, NYCapital District, Hudson Valley-Regulatory oversight for pesticides applications
-Review Article 15 Aquatic Pesticide Permit applications
-Render permit decisions relating to Article 15 Aquatic Pesticide applications
Primarily aquatic plants
Meredith TaylorInvasive Species BiologistNew York City Department of Environmental ProtectionKingston, NYNYC Water Supply Watershed- Early detection species moving into the area that pose a threat to water quality
- hydrilla, quagga mussel, northern snakehead, Asian carp, round goby, etc.
Hydrilla, zebra mussel, Asian clam, water chestnut
Hannah CoppolaAquatic Invasive Species Program ManagerCapital Region Partnership for Regional Invasive Species Management (Capital Region PRISM)Ballston Spa, NYAIS management throughout the Capital Region PRISM Counties;
Watercraft Inspection Steward Program at boat launch locations throughout the CRP
- As the AIS Program Manager for the Capital Region PRISM, I have a vested interest in understanding and preventing the spread of AIS on the Hudson River.
- Surveys for AIS are conducted by Capital Region PRISM staff.
- Multiple launch locations for the Watercraft Inspection Steward Program are located on the Hudson River.
- Predominately Eurasian water-milfoil, curly-leaf pondweed, and water chestnut
- Survey and work with all AIS throughout the Capital Region PRISM
Devin DiGiacopoAquatic Invasive Species Program CoordinatorLower Hudson Partnership for Regional Invasive Species Management (LHPRISM) / Teatown Lake ReservationTeatown Lake Reservation, Ossining, NYLower Hudson Valley, NYMy primary responsibility as the Aquatic Invasive Species Program Coordinator is managing the Aquatic Invasives Strike Force (an AmeriCorps program hosted by the New York-New Jersey Trail Conference and funded by the Lower Hudson PRISM). The crew surveys and maps AIS occurrences throughout the Lower Hudson region, assists in outreach events and trainings, participates in water chestnut removals and special partner projects, and conducts watercraft inspections for the LH PRISM Watercraft Inspection Steward Program.Primarily water chestnut (Trapa natans), but my crew surveys for all native and invasive aquatic plant species.