A section of the Snake River in southern Idaho, about 150 river miles upstream from Oregon, is closed due to an infestation of invasive quagga mussels.
The last line of defense against the unwanted, aquatic invaders is a boat inspection station in Ontario, Oregon, where staff are on high alert.
“I’ll start by looking at the prop. Most boats will have an open prop, so I’ll get a flashlight out and check inside it to make sure there’s nothing. Any areas that are obscured from view, I’ll try and look in there,” said Beck Harper, Oregon Department of Fish and Wildlife (ODFW) Aquatic Invasive Species Technician.
The larval form of quagga mussels are the size of a grain of sand and easily missed by a casual observer.
“Anytime we have a boat that’s coming from a contaminated waterway, even if they’ve already been inspected and hot washed, we always do a real thorough investigation into those boats just to make sure they are safe when they leave our check station because they may not encounter another check station on their way home,” said Libby Adams, an ODFW boat inspector. “In my mind, we are one of the last defenses before they get home and maybe enter Oregon waterways next. We want to make sure they aren’t carrying anything on their boat that could potentially harm Oregon.”
The ODFW operates five boat inspection stations near state lines. They’ve detected invasive plants and animals on 287 boats so far this year and decontaminated 10 of them.
“We use 140-degree hot water on the hull and the engine and that will kill all the mussels,” said Rick Boatner, ODFW’s Invasive Species Wildlife Integrity Supervisor. “Before we do that, if we find a mussel-encrusted boat, we are actually going to scrape and then do a hot wash so we kill any we might have missed, but also so we are getting rid of some of the DNA off the boat.”
All vehicles towing or carrying watercraft into Oregon must stop at any boat inspection station that is open to inspect for aquatic invasive species. The stations are open if large, orange “Boat Inspection Ahead” signs are posted.
All watercraft, regardless of size — canoes, kayaks, paddleboards, inflatable rafts or rigid fiberglass or aluminum boats — must stop and be inspected.
“When somebody pulls up, it’s really important that they have a pleasant greeting. I ask them a lot of general questions. Their name. Their zip code to get a little information about them. Then we roll into ‘Where’s your last water body? When was that?’ That’s information we collect in case that water body is contaminated and we need to retain those records. Once we are done with the little interview, I go behind the boat, inspect it, make sure we don’t see any invasive species. Then I sign the paper, give it to them and they are on their merry way,” Adams said.
The average boat inspection takes about five minutes. Many motorists will visit the restroom in the rest stop during the boat inspection and then continue their journey. But, if invasive species such as quagga mussels are detected, a thorough cleaning can take 1-2 hours.
How long can these things survive attached to a boat hull or inside an engine or bilge?
“The adult mussel, depending on temperature and humidity… they can live for a few days to as many as 30 days. The cooler temperatures, higher humidity, they can live longer outside the water,” Boatner said. “The veligers, the microscopic form, any standing water such as the in lower unit of your engine… in your ballast tank if you’re a wakeboard boat or your bilge area, they can live several days in there, again depending on temperature and humidity.”
Quagga mussels are destroying environments and infrastructure in The Great Lakes, Lake Powell and the Colorado River where they’ve gotten established.
Boat inspection stations such as the one in Ontario are Oregon’s only hope of keeping them out.
“They like to build on top of each other. They are almost like little Legos,” Adams said. “They continue to pile up on each other. They stick onto each other as their calcium carbonate shells form. They multiply until they get to a point where they clog pipes. There are really only two solutions: Change the pipes entirely or try to scrape them off, which isn’t really effective. What we are seeing is people are having to change pipes entirely. Because scraping them isn’t a plausible solution because of how encrusted and dense they are.”
This boat inspection station has nine confirmed kills of quagga mussels attached to boats. Stickers on the hot wash pressure tank attest to the search-and-destroy missions.
“If they get in the lower Columbia… each of those dams, millions of dollars just to keep their infrastructure open, and we aren’t even counting the irrigation districts, the water districts, how much money they are going to have to spend just to keep their pipes clear of these quagga and zebra mussels,” Boatner said.
Boat inspections are paid for by boat registration fees and waterway access permits.
The inspections and decontaminations, if necessary, are free and a minor inconvenience compared to the trouble quagga mussels would cause if they got established in a local body of water.
“Say for example Prineville Reservoir got infested. We’d do a containment. To go to Prineville then, you’d be going through a check station coming in, you’d be going through a check station going out—probably a decon—it would limit boat ramp access,” Boatner said. “Depending on manpower, it depends on what we could do but that’s what the plan is if a waterbody gets infested in Oregon.”
At last report, the effort the kill the quagga mussels in the Snake River near Twin Falls, Idaho, was successful.
For Oregon to remain free of the worst of these invasive species, boat owners need to step up their game by cleaning, draining and drying their boats every time they leave a lake, river or reservoir.