Starry stonewort is an invasive algae with a plantlike structure that is native to Eurasia. It was likely introduced to the Great Lakes from ballast water and has spread to inland lakes in New York. It was first discovered in the United States in the St. Lawrence Seaway in 1978. Stonewort is associated with several negative social and economic impacts throughout the Great Lakes.
Description
Starry stonewort has 4-6 long branches growing around each stem and can grow more than 7 ft. (2 m) tall in water more than 30 ft. (10 m) deep. It forms dense mats of vegetation that look like pillows (with plants of different heights) along the bottoms of ponds and lakes with still, alkaline water and forms star-like reproductive structures. It is tolerant of both salt and freshwater and tends to grow on sand and gravel in both shady and sunny areas.
Habitat and Distribution
Starry stonewort has been reported in fourteen counties in New York State: Cayuga, Chautauqua, Cortland, Franklin, Jefferson, Lewis, Monroe, Onondaga, Ontario, Oswego, Otsego, St. Lawrence, Tompkins, and Wayne. Unfortunately, starry stonewort is difficult to distinguish from closely related muskgrasses and stoneworts so there may be places where it has not yet been detected.
Spread?
Starry stonewort is named for its star-shaped reproductive structures, or bulbils, which can be transported in mud. Starry stonewort can also spread by fragments and is often found near docks and marinas indicating that watercraft likely transport this algae from site to site.
Environmental Impact
Starry stonewort negatively impacts native species by outcompeting native plants that provide food and shelter for native invertebrates and fish. Its dense mats of vegetation also negatively impact native fish spawning and phytoplankton (small native aquatic plants that are eaten by fish and invertebrates).
Management
Both chemical (herbicide) and manual (hand-pulling and harvesting) controls have been used with varying success. Research is currently being conducted throughout the Great Lakes Region for best management practices. Preventing the spread of this invasive is critical.
What can I do to help?
- Clean, drain, and dry your watercraft and equipment thoroughly before visiting other waterbodies.
- Inspect and remove debris and mud from boats, trailers, and equipment.
- Dispose of all debris and bait in trash cans or at disposal stations.
- Drain all water-holding compartments including live wells, bait wells, and bilge areas. If possible, visit a decontamination station and disinfect compartments with hot water (140°F) for at least 30 seconds.
- Dry boats, trailers, and all equipment before use in another water body. A minimum of 5-7 days of drying time in dry, warm conditions is recommended.
- Do not dump aquarium contents in any waterbodies, drainage ditches, or sewers.
- Use certified bait that is non-invasive and disease free.
- Learn how to identify starry stonewort and report any sightings.
- If you think you have found starry stonewort:
- Take photos
- Email the photos, noting where it was found (GPS coordinates preferred), [email protected] OR
- Submit a report through iMapInvasives, OR
- Contact your local Partnership for Regional Invasive Species Management.