Quagga Mussels and Oregon
ODFW Holding Statement
With the discovery of quagga mussels in Lake Mead, Nevada, the Oregon Department of Fish and Wildlife is greatly concerned that they could be coming to Oregon soon on recreational watercraft. Although much of what is written about quagga mussels and their close cousin the zebra mussel revolves around the clogging of pipes and boat engines, these small mussels can also have severe impacts to the ecosystems they invade.
Quagga mussels are filter feeders, which means that they remove almost all microscopic floating plants (phytoplankton) and animals (zooplankton ) from the water. Since each quagga mussel can filter 1 liter of water per day and they can achieve very high densities (up to 700,000 per square meter), an invasion of quagga mussels can quickly strip this important food source out of a lake or stream’s ecosystem. As a result, phytoplankton and zooplankton would not be available to our native minnows, young fish, mussels and invertebrates.
In the Great Lakes, some forms of phytoplankton have been reduced by 80 percent, as a result, a small, shrimp-like creature called diporeia which relies upon the same food sources as quagga has decreased from a density of 5,200 per square meter in 1994/1995 to 1,800 per square meter in 2000. In 2005, diporeia were found at only 300 per square meter. Historically, whitefish in Lake Michigan relied on diporeia for as much as 75% of their diet. Now, as much as 40% of a whitefish’s diet is composed of quagga mussels. And while whitefish numbers have not yet declined, the average weight of a 7 year-old whitefish has dropped from more than 5 pounds in 1988 (just before zebra mussels were discovered in the Great Lakes) to 1.6 pounds in 2005.
In addition, quagga and zebra mussels, through their filter feeding, can accumulate organic pollutants (PCB’s and PAH’s) up to 300,000 times higher than occur in the natural environment. These pollutants are then passed up the food chain to any fish or waterfowl that feed on quagga or zebra mussels. Accumulation of these contaminants in these species could result in decreased reproduction success. In addition, the consumption of these tainted fish or waterfowl could become a human health concern and influence or create harvest restrictions.
For more information on quagga and zebra mussels please visit the following web sites:
Summary of Washington’s Boat Check Laws
- Both the Washington State Patrol and the Department of Fish and Wildlife have the authority to stop and inspect recreational and commercial watercraft.
b. Department of Fish and Wildlife may establish random check stations to inspect watercraft.
- Definition of “Recreational and commercial watercraft" includes the boat, as well as equipment used to transport the boat, and any auxiliary equipment such as attached or detached outboard motors.
- The Department of Fish and Wildlife is authorized to require anyone transporting a recreational or commercial watercraft to stop at a check station, provided that:
- It is well marked
- Staffed by one uniformed fish and wildlife officer
- Individuals stopped at these check stations who possess a contaminated watercraft are exempt from all fines, prosecution or forfeiture related to the possession of prohibited aquatic species if the individual complies with all directives for the proper decontamination of the watercraft and equipment.
- Based on “articulable” facts that a person is transporting prohibited aquatic plant or animal species, a fish and wildlife officer may temporarily stop and inspect a watercraft and associated equipment to make sure that it is not transporting prohibited species.
- Articulable facts in this case could simply be a boat from a zebra/quagga mussel infested state. (Based on personal communications with Officer Eric Anderson with the Washington Department of Fish and Wildlife.)
- A person is guilty of unlawfully avoiding aquatic invasive species check stations if the person fails to:
(b) Stop and report at a check station if directed to do so by a uniformed fish and wildlife officer.
- Unlawfully avoiding aquatic invasive species check stations is a gross misdemeanor.
- The Department of Fish and Wildlife may coordinate with other states on inspection requirements and may determine when other state inspections meet Washington standards.
1. An additional $2 annual fee is tacked on to every boat registration to fund the boat inspection and enforcement program.