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Task Force:

Hudson River Aquatic Invasive Species

IN THIS SECTION

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

Species

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.

Plants

Scientific Name	Common Name	Capital Region Tier Rank	Lower Hudson Tier Rank	NYS Tier Rank	Morphology	NYS Risk Assessment	Monitoring	Management
Aldrovanda vesiculosa	Waterwheel	1a	1	2	floating	No assessment available	Visual, rake toss	No effective control method known.
Alternanthera philoxeroides	Alligatorweed	1c	1	1b	emergent, floating	No assessment available	Visual, rake toss	Physical management is not effective. A biocontrol exists but is not commercially available. Several herbicide treatment options are available.
Butomus umbellatus	Flowering rush	2	2	untiered	emergent	M	Visual	Small 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 caroliniana	Carolina fanwort	1a	2	3	submerged with floating/emergent flowers	H	Visual, rake toss	Mechanical removal, water level manipulation, and chemicals have been tried in the Northeast with limited success.
Egeria densa	Brazilian elodea	1a	2	2	submerged	H	Visual, rake toss	No effective control method known.
Pontederia crassipes	Water hyacinth	5	2	2	floating	NotAssessed	Visual	Manual 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 palustris	water violet	not ranked	not ranked	not ranked	submerged with emergent flowers	No assessment available	Visual, rake toss	No effective control method known; no resources found.
Hydrilla verticillata	Hydrilla	1a	2	2	submerged	VH	Visual, 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-ranae	European frogbit	2	2	4	floating	VH	Visual, rake toss	Chemical control has been effective on the Great Lakes. Physical removal may provide temporary control.
Ludwigia adscendens	floating water primrose	not ranked	1	1b	emergent, floating	No assessment available	Visual	No 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 grandiflora	Large flower primrose willow	1b	2	not ranked	emergent, floating	VH	Visual	No 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 hexapetala	six petal water primrose	not ranked	not ranked	not ranked	emergent, floating	No assessment available	Visual	No 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 peploides	Floating primrose willow	1b	1	2	emergent, floating	VH	Visual	Manual control is not advisable as it can easily disperse fragments. Chemical control is being piloted on the Peconic River.
Marsilea quadrifolia	European water fern	5	2	untiered	slightly submerged, floating, or emergent. Can grow in wet terrestrial habitat	Uknown	Visual, rake toss	No effective control method known. Chemical treatment with bensulfuron methyl has been successfully used in Japan.
Murdannia keisak	Marsh dewflower		1	1a	emergent	H	Visual	Retrieving data. Wait a few seconds and try to cut or copy again.
Myriophyllum aquaticum	Parrot feather	1a	1	2	submerged, emergent	H	Visual, rake toss	Physical and chemical control methods have been tried with limited success.
Myriophyllum spicatum	Eurasian watermilfoil	4	4	4	submerged, floating	VH	Visual, rake toss	No effective control method known.
Nasturtium officinale	Watercress	3	3	untiered	emergent, floating	M	Visual, 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 nucifera	Sacred lotus/Pink lotus	1b	1	untiered	submerged with floating leaves and emergent flowers	M	Visual	Retrieving data. Wait a few seconds and try to cut or copy again.
Nitellopsis obtusa	Starry stonewort	2	1	4	submerged	No assessment available	Visual, 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 peltata	Yellow floating heart	2	2	3	submerged with floating leaves and emergent flowers	H	Visual	Repeated 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 stratiotes	Water lettuce	5	1	2	floating	NA	Visual	No effective control method known.
Stratiotes aloides L.	Water soldiers	1c	1	1a	submerged, emergent	NA	Visual, 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 bispinosa	Two Horned trapa	not ranked	not ranked	not ranked	floating	No assessment available	Visual	Foliar 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 natans	Water chestnut	4	3	4	floating	VH	Visual	Foliar 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.

Animals

Scientific Name	Common Name	Capital Region Tier Rank	Lower Hudson Tier Rank	NYS Tier Rank	NYS Risk Assessment	Monitoring	Management
Bithynia tentaculata	Mud bithynia	2	2	3	NA	eDNA, visual surveys in shallow water, dip netting in deeper water	No effective control method known.
Bythotrephes longimanus	Spiny waterflea	2	1	3	Not assessed	eDNA, zooplankton nets with a mesh size of 250 microns.	No effective control method known.
Carcinus maenas	Green crab	1a	1	untiered	NA	eDNA, trapping	Trapping 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 pengoi	Fishhook waterflea	1b	1	3	VH	eDNA, zooplankton nets with a mesh size of 250 microns.	No effective control method known.
Channa argus	Northern snakehead	1a	1	2	H	eDNA	Physical removal may be impactful for small infestations, but it is difficult to prove success. Chemical management options are not selective.
Corbicula fluminea	Asian clam	4	2	3	H	eDNA	Chemical and mechanical methods may be used in closed systems such as power plants, but management is prohibitively complex in natural aquatic systems.
Ctenopharyngodon idella	Grass carp	not ranked	2	untiered	M	eDNA, electrofishing, trapping	Increased harvest, electrofishing, trapping. Introduction of sterile males or monosex tetraploids.
Dreissena rostriformus bugensis	Quagga mussel	2	1	3	VH	eDNA	No effective control method known.
Eriocheir sinensis	Chinese mitten crab	2	2	3	M	eDNA, trapping	No effective control method known.
Gymnocelphalus cernuus	Eurasian ruffe		1	not ranked	Not assessed	eDNA	no effective control method known. Chemical treatments may be available, but they are not selective.
Hemigrapsus sanguineus	Asian shore crab	1a	2	3	VH	eDNA	No effective control method known.
Hemimysis anomala	Bloody red shrimp	3	2	3	H	eDNA, Trapping with plankton nets.	No effective control method known.
Hypophthalmichthys harmandi	Largescale silver carp	not ranked	1	not ranked	M	eDNA	No effective control method known; no resources found.
Hypophthalmichthys molitrix	Silver carp	not ranked	1	1	H	eDNA	No effective control method known. Barriers may be used to prevent further spread.
Hypophthalmichthys nobilis	Bighead carp	not ranked	1	"buffer"	M	eDNA	no effective control method known, but barriers may be used to prevent further spread.
Misgurnus anguillicaudatus	Oriental weatherfish	1a	2	3	H	eDNA	No effective control method known.
Neogobius menalostomus	Round goby	1a	1	4	H	eDNA, trapping	Fish pesticides, physical barriers, and bioacoustic or pheromone traps may be effective for managing and/or preventing further spread.
Potamopyrgus antipodarum	New Zealand mud snail	1a	1	2	He	eDNA	Chemical options may be available. A biological control is being investigated.
Procambarus clarkia	Red swamp crayfish	1b	1	2	Not assessed	eDNA	Control methods have been proposed but none have proven effective yet.
Procambarus virginalis	Marbled crayfish	N/A	N/A	N/A	Not assessed	eDNA	No effective control method known.
Proterorhinus semilunaris (P. marmoratus)	Tubenose goby	not ranked	1	untiered	M	eDNA, trapping	No effective control method known, but acoustic deterrents and barriers may prevent further spread.
Scardinius erythrophthalmus	Rudd	3	2	untiered	M	eDNA	Trapping 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 tinca	Tench	1a	1	2	H	eDNA	No effective control method known.

Sites

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 for more details about the prioritization methods and a list of top-scoring water bodies.

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.

Resources

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

PLANTS

ANIMALS

ID Guides and Tools

General

Plants

Animals

Meeting Summaries

Round_goby_a_invasive_fish_in_a_lot_of_countries

Directory

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

Name	Title	Organization	Location	Geographic Scope of Work	Description of work and interests	Species
Lindsay Charlop	Estuary Training Program Coordinator	Hudson River National Estuarine Research Reserve	Staatsburg, NY	focused on the Hudson River Estuary	Coordinating and facilitating the Hudson River Aquatic Invasive Species Task Force	As needed
Heather Gierloff	Reserve Manager, Marine habitat manager for regions 3 and 4	Hudson River National Estuarine Research Reserve	Staatsburg, NY	Hudson 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 Fernald	Research Coordinator	NYSDEC and Hudson River National Estuarine Research Reserve	Staatsburg, NY	Hudson River Estuary; specifically the HRNERR component sites, which are Stockport Flats, Tivoli Bays, Iona Island, and Piermont Marsh	I 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 McGlynn	Aquatic Invasive Species Program Coordinator	NYSDEC	Albany, NY	New 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 Pearson	Research Biologist	NYSDEC	Albany, NY	New York State	Working to determine aquatic invasive species distribution, abundance, life history and management strategies.	Flora and fauna
Nicole White	Croton Hydrilla Control Project Manager	NYSDEC Invasive Species Coordination Section	NYSDEC Region 3	New 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 Smith	Land Stewardship Coordinator	Scenic Hudson	Poughkeepsie, NY	Albany 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 Shapley	Co-Director of Science and Patrol	Riverkeeper	Ossining, NY	Hudson River Watershed and NYC Watershed	- Impacts on native biota - Impacts on water quality - Impacts on drinking water quality - Impacts on habitat/ecology
David Decker	Land Steward	Constitution Marsh Audubon Center	Garrison, NY	We 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 Marsh	Phragmites, water chestnut
Lynde Dodd		US Army Research and Development Center	Lewisville, TX	USACE 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 Brincka	Invasive Species Biologist	NYS OPRHP	Albany, NY	New York State	Invasive 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 species	Typically new or emerging threats
Brian DeGasperis	Restoration Biologist	Hudson River National Estuarine Research Reserve	Staatsburg, NY	Hudson 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 Miller	Habitat Restoration Coordinator	NYSDEC Hudson River Estuary Program	Staatsburg, NY	Hudson River	Hudson River habitat restoration including shorelines, shallows and intertidal areas. Manage small scale Phragmites management efforts.	Phragmites
Scott Cuppett	Watershed Program Manager	Hudson River Estuary Program	New Paltz, NY	Hudson watershed between Troy and NYC	Work 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 Pendleton		NYSDEC	New Paltz, NY	Hudson River, Troy to George Washington Bridge	Long-term fish monitoring	Round goby
Gregg Kenney	Marine Biologist	NYSDEC	New Paltz, NY	Hudson River tidal estuary and tributaries	We 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 Kuonen	Hudson Estuary Resilience Specialist	New York Sea Grant	Kingston, NY	Hudson 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 George	Biologist	U.S. Geological Survey	Troy, NY	Primarily 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 Young	Chief Botanist	NYNHP	Albany, NY	New York State	We 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 Dangler	Biologist- Senior Project Manager	U.S. Army Corps of Engineers	Wartervliet, NY	NYSDEC Regions 4-5	I 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 Spada	Aquatic Ecologist	NYC Department of Environmental Protection	Kingston, NY	Delaware, Greene, Putnam, Schoharie, Ulster and Westchester counties	Aquatic 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 Solan	Section Chief	New York State Department of Environmental Conservation; Bureau of Pesticide Management	Schenectady, NY	Capital 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 Taylor	Invasive Species Biologist	New York City Department of Environmental Protection	Kingston, NY	NYC 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 Coppola	Aquatic Invasive Species Program Manager	Capital Region Partnership for Regional Invasive Species Management (Capital Region PRISM)	Ballston Spa, NY	AIS 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 DiGiacopo	Aquatic Invasive Species Program Coordinator	Lower Hudson Partnership for Regional Invasive Species Management (LHPRISM) / Teatown Lake Reservation	Teatown Lake Reservation, Ossining, NY	Lower Hudson Valley, NY	My 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.