New AIS: Starry stonewort shows up in 2021...
Damage from aquatic invasive species (AIS) impacts our recreational activities, our economy and our ecology, and can change how we enjoy and use our lake and adjoining streams. However, we can work together to mitigate their spread to other water bodies and defend our lake against other invaders - both plant and animal species.
In July 2021 the Minnesota DNR confirmed the existence of the invasive Starry stonewort algae, which was found near Anderson’s Cove Resort in Steamboat Bay in Leech Lake. A DNR invasive species specialist confirmed Starry stonewort throughout the marina, around and under docks and boats.
Starry stonewort is an algae that looks similar to native aquatic plants and can form dense mats, which can interfere with use of a lake and compete with native plants. It is most likely spread when fragments have not been properly cleaned from trailered boats, personal watercraft, docks, boat lifts, anchors or other water-related equipment.
Starry stonewort impacts:
New CD3 decontamination stations will be placed at launches in Cass County lakes for the 2022 season. The self-serve stations provide tools especially designed to help boaters remove fragments of Starry stonewort and other AIS from watercraft — including a wet-dry vacuum, a high-pressure air hose, scrubbing brushes, grabbing tools and lights to help boaters see at night. Here's the latest news coverage: according to an article in the Minneapolis Star Tribune (Jan. 9, 2022) and a Jan.4 Minnesota Public Radio piece.
For more information, here is additional news coverage about Starry stonewort's discovery in Leech Lake and a demonstration of the CD3 station presented by the Mille Lacs Band Department of Natural Resources.
Zebra mussels are small animals with a striped, D-shaped shell composed of two hinged valves joined by a ligament. The shells are typically one-quarter inch to one and one-half inches long, depending on age, with alternating yellow and brownish colored stripes. Adults are typically fingernail-sized. Zebra mussels attach to hard surfaces underwater.
The spread of Zebra mussels comes primarily through the movement of water-related equipment, including boats, boat lifts, swim rafts, and docks. Animals that live underwater, an adult female can produce 100,000 to 500,000 eggs per year. Fertilized eggs develop into microscopic, free-living larvae, called "veligers," that form shells. After two to three weeks, the veligers settle and attach to a firm surface using tiny fibers called byssal threads. Beds of zebra mussels can reach tens-of-thousands within a single square yard.
Cass County AIS Inspector Report 2021
In 2021, Cass County AIS inspectors checked nearly 6,000 boats at Leech Lake launches, logging 2,280 hours of inspection time. Leech had a 99.7% compliance rate for the Minnesota boat plug law. Read more...
Summary of Leech Lake Phytoplankton Data, 2017-2021
This report summarizes the 2017-2021 phytoplankton data from Leech Lake and examines patterns among years. It is based on five years of water sampling, conducted by association members. The datasets are not enough to describe or quantify trends over time, but they provide a baseline of information early in the establishment of zebra mussels in the lake -- and as the population grows to become well-established and widespread. Report by. Heidi M. Rantala, Ph.D., Fisheries Research, MN DNR, March 2022
We're living with zebra mussels. Now what?
Here's the low-down on zebra mussels from the Minnesota Aquatic Invasive Species Research Center.
Eurasian watermilfoil is a rooted, submerged aquatic plant. The leaves appear green while the stems are white to reddish. A perennial plant, it flowers twice a year, usually in mid-June and late-July. It can grow up to 20 feet tall, but typically only grows three to nine feet tall. It creates canopy-like structures as it grows toward the water’s surface. It primarily establishes through vegetative fragmentation—a fragment can break off, settle in the sediment, grow roots, and establish a new plant. The plant dies back in the fall, but the root system can survive the winter and begin growing again in the spring. For a complete description of the plant and its native look-alikes, see the DNR website.
You can help stop the spread of aquatic invasive species
Minnesota law requires you to:
- Clean watercraft of all aquatic plants and prohibited invasive species.
- Drain all water by removing drain plugs and keeping them out during transport.
- Dispose of unwanted bait in the trash.
- Dry docks, lifts, swim rafts and other equipment for at least 21 days before placing equipment into another water body.
Threats from Other Invasive Species
Stop the Spread of Spiny water fleas
Spiny water flea (Bythotrephes longimanus)
Spiny water flea Fact Sheet: "Walleye growth decreases after Spiny water flea and Zebra mussel invasion"
Minnesota Aquatic Invasive Species Research Center (MAISRC)
Minnesota State Watercraft Inspection Program