July 25, 2005
NEEDED: Hydrilla Hunters to Search for a Most Unwanted Species
It’s summertime, and Michigan Sea Grant is looking for volunteers to check the state’s Great Lakes bays, inland lakes and other waterways for the invasive plant Hydrilla verticillata.
In 2004, dozens of Hydrilla Hunters reported searching 72 lakes in 43 counties, according to a Sea Grant survey. No one found the invasive aquatic plant, which is good news to resource managers. However, it has been reported in Pennsylvania and is very close to New York, so Michigan Sea Grant continues to lead the state’s Hydrilla Hunt to help prevent the species from gaining a foothold in this state’s waterways.
The aquatic plant forms large, dense mats on the water’s surface, creating havoc with the ecosystem and interfering with recreation, according to MSU Extension’s inland lake specialist Howard Wandell. It has clogged waterways in many southern states and has been found as far north as Maine, Massachusetts and the state of Washington.
Wandell says it’s very difficult and expensive to eradicate. “We have very limited effective options for controlling this invader, so it’s important to keep it out of the state if we possibly can and control it quickly—before it spreads—if it does appear.”
Michigan Sea Grant spokesperson Carol Swinehart says one key reason to take a preventive approach lies in the plant’s name. “In Greek mythology, Hercules fought a losing battle with nine-headed serpent named Hydra. When he cut off one head, two more would emerge. Michigan wants to avoid such a losing battle with this plant which can reproduce rapidly in at least four ways—from stem fragments, from its flowers, by a bud-shaped growth called a turion, and through underground tubers that can overwinter.”
“If someone thinks they've found it, we ask that they compare the plant with the image on our web site or the Hydrilla Hunt card. The card provides instructions on how to collect a plant sample, how to distinguish it from the native aquatic plant elodea, and where to send it for identification. If it has all the characteristics described there, send us a sample so that we can make sure,” Swinehart says. Hydrilla Hunt cards and other information about the species are available online.
The cards also request basic contact and location information. Swinehart requests people to report where they’re searching by sending an e-mail to cys@msu.edu. Put Hydrilla Hunt in the subject line and the name of the lake, pond, or river and the county in the text of the message. Suggested searching strategies include the following:
- Conduct the search early in the morning on a calm, sunny day.
- Start with the public boating access, if available.
- Go slowly around the shoreline wearing polarized sunglasses to reduce glare.
- Look in water up to 20 feet deep.
- Pay special attention to any unusual plant growth.
- Check the lake’s outlet and any flow-restricting structures such as dams and spillways.
- Check for plants near stream inlets and in shallow bays.
It is illegal to take Hydrilla across state lines, so Michigan residents and visitors can help by following good prevention practices when moving watercraft or other water recreation gear from one body of water to another. More information on prevention practices is available at www.protectyourwaters.net
Michigan Sea Grant is a collaborative program of Michigan State University and the University of Michigan, conducting Great Lakes research, education and outreach. It is one of 30 Sea Grant programs supported by the National Sea Grant College Program of the National Oceanic and Atmospheric Administration (NOAA). |
