NYSG Launch Stewards: Helping to Control the Spread of Aquatic invasive Species (AIS)

The overall goal of the New York Sea Grant Launch Steward Program was to increase public awareness on identifying aquatic invasive species (AIS) and how the public can help control the spread of AIS to different bodies of water.

So, what are invasive species?

• Invasive species are non-native (or alien) to the ecosystem and their introduction causes or is likely to cause economic or environmental harm. 
• Aquatic invasive species can outcompete the native species that occupy the same niche. 
• Some of the AIS that are common in New York bodies of water include the zebra mussel, Eurasian watermilfoil, Hydrilla and the European water chestnut. 
• Zebra mussels have been linked to food web disruptions, causing a bottom-up trophic cascade which adversely affects the lake ecosystem population dynamics. 

Eurasian watermilfoil, Hydrilla, and European water chestnuts form thick mats of vegetation at the water’s surface, blocking sunlight for native plants and decreases in dissolved oxygen levels, leading to fish kills.

Early detection is crucial to controlling AIS as smaller populations are easier to eliminate or manage, than larger ones. Individually removing plants by hand with small infestations rather than large established areas may help to reduce overall management costs.

Volunteers and Launch Stewards at a European water chestnut hand-pull on the Oswego River near Battle Island, Fulton, NY. During this event, the group removed 1,250lbs. of water chestnut;
Photo by: Richard Drosse

AIS Hand-Pulls 

Hand-pulls involve the public/volunteers in physically removing unwanted species from a body of water. On July 14, 2014, in partnership with the Oswego County Soil & Water Conservation District (OCSWCD), St. Lawrence Eastern Lake Ontario Partnership for Regional Invasive Species Management (SLELO PRISM), and the Oswego County Guides’ Association, the NYSG Launch Stewards assisted in educating participants about AIS prevention and to help stop the spread of the European water chestnut in a hand pull event on the Salmon River. Approximately 30 participants (including many local volunteers) removed more than 300 pounds of European water chestnut from the river.

European water chestnuts collected from the Salmon River, Launch Stewards Ashleigh Grosso (Left) and Rob Tornatore (Right); Photo By: NYSG Chief Launch Steward, Brittney Rogers

To learn more about organizing a local AIS hand-pull event, please reference the "Steps and Procedures to Help Organize an Invasive Plant Removal and Disposal" online at http://www.seagrant.sunysb.edu/ais/pdfs/CCD-StewSperaWaterChestnutFactSheet1012.pdf.

Mechanical and Herbicide Control of AIS

Large populations of AIS may require the use of mechanical harvesters or pesticides.

Mechanical harvesting machines cut and collect the aquatic plants, removing them from the water by a conveyor belt system. The plant matter is stored in the harvester until the collection can be removed and disposed of away from the water body. 

Mechanical weed harvester removing aquatic plants on Sodus Bay, 2013.
Photo by: NYSG Coastal Community Development Specialist, Mary Austerman

The application of herbicides is also used to achieve control of AIS. Highly infested areas often must be treated for multiple years to eliminate the invading population. Aquatic herbicides are chemicals specifically formulated for use in water to kill or control aquatic plants.

Aquatic herbicides are sprayed directly onto floating or emergent aquatic plants or are applied to the water in liquid or pellet form. Most herbicides have restrictions on the use of the water body immediately after treatment, lasting up to 30 days, depending on the dose rate or use of the area. Follow-up monitoring should track the applied chemical and changes in the plant communities, water quality conditions, and impaired uses.

The effectiveness for any given herbicide treatment varies with the treatment design, and the conditions of the water body and treatment site listed.  In general, the effectiveness of an herbicide treatment will last anywhere from several weeks to several months, usually corresponding to a single growing season. 

Since seeds and roots frequently are not affected by treatment, once the chemicals have degraded or washed out of the system, plant growth will resume, and reapplication may be necessary. Effectiveness rarely carries over to the next growing season.  

Please note: only licensed applicators should handle herbicides

Public Education About AIS

Another means of controlling AIS is through public education. The NYSG Launch Stewards have educated boaters and members of the non-boating public about such programs as Clean, Drain, Dry watercraft inspection. These programs have led to increased public awareness on the various AIS that plague our lake ecosystems; as well as the vectors in which they can spread. With the Launch Stewards helping patrons visiting the boat launches identify AIS, the Launch Stewards were able to inform the public how they could become stewards themselves, by reporting sightings of suspected invasive species to iMapInvasives.org. Follow the previous link to learn more about these efforts. 

2013 NYSG Launch Steward Megan Pistolese conducting a voluntary watercraft inspection with a local boater at Henderson Harbor Boat Launch. Photo by: NYSG Chief Launch Steward, Brittney Rogers

Various organizations such as OCSWCD, SLELO PRISM, and Save Our Sodus were able to locate several priority sites with European water chestnuts. Once located, these organizations, the Launch Stewards and many concerned patrons helped target and remove these infestations from several bodies of water. Throughout 2014 Launch Steward Program, the Launch stewards were able to remove a total of 2,050 pounds of European water chestnuts in three separate locations, which helped restore large portions of New York’s aquatic ecosystem.