The Fern Ridge Reservoir just west of Eugene, Ore., is a popular recreation spot for boaters and swimmers during the spring and summer months. The marina attracts freshwater sailors and provides ample fishing opportunities for anglers. There’s only one problem: An invasive species is steadily taking over the lake, and the worse it gets, the less welcoming the lake becomes.
The invader, known as Eurasian watermilfoil, is an aquatic plant that forms tangled mats as it grows. Eurasian watermilfoil tends to show up in shallow waters where it can access sunlight. These thick tangles are obstructive enough to stop boat motors from working, and they can prevent kayakers from maneuvering through the water.
Not only is the milfoil an obstacle, but it also saps oxygen from the water and can cause fish to suffocate. As the fish decay at the bottom of the lake, the smell can get pretty strong.
For boaters like Scott Coleman, the owner of Underway LLC and manager for the Orchard Point Marina, it’s a worrying problem. “Specifically in this marina, if this plant really got going and clogged up the marina, then you wouldn’t be able to get your boat through here,” Coleman says. “And, it would be no fun to swim in.”
Last year, Coleman and a band of concerned marina users decided to take action. After consulting with Tania Siemens, WISE Program coordinator, and Sam Chan, invasive species specialist at Oregon Sea Grant, the boaters created a management plan that could correct their core problem: standing water.
The lake is drained every winter, and in places where the water fully drains, the ground freezes and the milfoil roots die, unable to survive into the following summer. But in some areas, the water doesn’t drain completely, leaving shallow pools. In these areas, the ground doesn’t freeze, preserving the milfoil roots and allowing them to continue multiplying year after year.
Marina volunteers decided that by digging a series of trenches in the marina mud, the water could drain, giving the ground a chance to freeze, which might kill the invasive milfoil roots. In order to do that, they needed to get permission from the Army Core of Engineers, who has jurisdiction over the lake.
In 2012, Gunnar Schlieder, an engineer with Geoscience, Inc., drafted a plan for the trenching while Lane County applied for a permit, receiving permission on Jan. 25 of this year. With the permit secured, Coleman and his group immediately organized a volunteer day, and on Feb. 2, around 25 volunteers, including moorage holders from Orchard Point and Richardson Park Marina, spent six hours digging an interconnected web of ditches, all with the goal of freezing out the milfoil. “We hope that if we can expose the milfoil to frost, it will go away,” Coleman says.
They received the permit a little late in the game this year, since overnight frosts get less likely as Oregon shifts into spring, but Coleman says the permit will allow his group to continue their efforts next year. As far as he’s concerned, it’s all part of a larger effort to educate the boaters about invasive species and make sure other invaders won’t threaten his marina.
Dan Weise, a Richardson Park Marina slip holder and local sailor, and Roger Bailey from the City of Eugene Recreation Division were instrumental in launching this volunteer effort. “We’re just defending our marina from the stuff, so to speak,” Coleman says. “But on a larger scale, if you look at what some of the plants and animals have done on the East Coast – the Burmese python, the snakehead fish – it doesn’t take long and you’ve lost the war.”
A few simple steps can be taken to prevent the spread of invasive species while boating. Remember the mantra, “Clean, Drain, Dry,” and keep boats invasive species-free by following a few simple steps:
1. Clean as thoroughly as possible, using a boating wash station or commercial car wash, if possible. Scrub off all residue from boats, equipment and boots.
2. Drain all the water from boats and boating equipment, including ballast water.
3. Dry all surfaces, making sure that no water is left. This will prevent invasive aquatic species from surviving.
For more information, check out these sites:
Oregon Department of Fish and Wildlife – Invasive Species
100th Meridian Initiative – Aquatic Nuisance Species