Invasive Species

Devils Lake is under constant threat of invasion by some plant or animal that is not native to this area. With no natural enemies, many of these non-native species multiply and crowd out native species. The whole food web is disrupted. Invasive species are often carried in by
boats. Boat users click here to find out what you can do.
"Stop Harmful Aquatic Species" signs are posted at boat launch ramps at Regatta Grounds and Holmes Road Park. Portland State University and other agencies worked together on the signs.
• Stop Aquatic Hitchhikers! Prevent the transport of nuisance species. Clean all recreational equipment. (national Aquatic Nuisance Species Task Force, U.S. Fish and Wildlife Service) -
It's Time to Come Clean (Oregon State Marine Board) -
Invasive species - Why Should I Care? (BoatU.S. Foundation for Boating Safety & Clean Water)

Read about Diamond Lake near Medford and their boat wash program -

In Devils Lake
Two invasive aquatic plants in Devils Lake are:
  Brazilian elodea
  Eurasian watermilfoil

Other invasive species in Devils Lake include parrot feather, yellow flag iris, Japanese knotweed, and reed canary grass.

In yards, parks and open spaces around the lake
Remove English ivy, holly, and purple loosestrife.
"Whenever possible, remove any vine plants growing on or around the tree trunk, especially invasive plants such as English ivy, poison oak, poison ivy, and trailing blackberry. Such growth can add excessive weight loads to tree branches, increase wind stresses which predispose the tree to mechanical failure, and can set up conditions favorable to decaying organisms in plant wounds." ("Tree Team," published by the Oregon Heritage Tree Program in Salem)

English Ivy
English ivy has two basic profiles. The immature, or juvenile, form is the familiar vine with pointy green leaves that grows on the ground or climbs a fence, wall, post, or tree. The plant may remain in this form for years. The second form is when it matures and propagates. Then the leaves become rounder and the plant produces a small greenish-white flower (somewhat like mistletoe) and fleshy, purple-black berries. Portland Parks has a "No Ivy League" program that Lincoln City should copy.

Knotweed - do not cut
Watch for the three types of knotweed: Giant, Himalayan, and Japanese. Knotweed can take over Himalayan blackberry habitat. It is a hardy plant with a huge root system. Do not cut down the plant. Contact the Lincoln Soil and Water Conservation District's at download pdf file

Purple loosestrife

Purple Loosestrife has been targeted for removal around the lake. Volunteer work parties are held in the summer months to remove the root. Call the Devils Lake Water Improvement (DLWID) office at 994-5330 for the work dates. Brochures about loosestrife are available at the DLWID office. Beetles have been brought in as a means of biological control.

Behind the brilliant guise of purple loosestrife hides an ugly strategy: the takeover of wetlands. Loosestrife is displacing the native wetland plants at an alarming rate. When the conditions are right, a small isolated group of loosestrife plants can spread and cover a marsh in only one growing season. Once established, loosestrife is difficult to control.   The shallow woody root system forms a dense mat, making adult plants difficult to pull. If the entire root is not taken, then it will resprout. If plants are mowed, the stem pieces will actually send out new roots, eventually become anchored and begin new colonies.
   Besides these vegetative maneuvers, each plant's flower spike has the capability to produce 120,000 seeds in a single season. These seeds remain viable when submerged for many years while waiting for the opportunity to sprout. Then during a dry summer, these seeds germinate suddenly. Often the dispersal is such that the seedlings have the capacity to completely replace native vegetation.

Because purple loosestrife is so widely distributed in the United States, it is unlikely that elimination is possible. But, because the species has not become well established in many areas, halting the spread of loosestrife and eliminating it from newly-invaded areas is certainly feasible.
   The key to stopping the spread of loosestrife lies in recognizing the plant when it first appears and eradicating it before it becomes a dominant part of the wetland ecosystem. By implementing the following measures, we can stem the invasion of loosestrife.
By Hand - Generally effective on small clusters up to 100 plants.
• Younger plants can be hand pulled.
• Older plants, especially those in bogs and deep organic soils, can be dug out.
• Roots must not be broken off or they will resprout.
• All plant parts must be removed, dried, and if possible, burned. Plant parts can reroot otherwise.
By Herbicide - May be necessary for clusters in excess of 100 plants (up to 3 acres).

(Lythrum salicaria)
WHEN TO LOOK FOR IT: Mid-July through the end of August when it is in bloom and easily recognized.
WHERE TO LOOK FOR IT: It is present on wet soils to shallow standing water; wet meadows, pasture wetlands, cattail marshes, stream and river banks, lake shores and ditches.
Growth Habit: Upright hardy perennial, bushy, up to 7 feet tall.
Flowers: Purple-magenta color. Flowers numerous on a long spike; 5-6 petals per flower.
Leaves: Vary, although usually opposite; linear shape and smooth edges. Attached directly (no stalk) to a four-sided stem.
Roots: Woody taproot with fibrous root system that forms a dense mat.
HOW IT SPREADS: It is a prolific seed producer; also grows from underground root and sprouts from broken-off plant parts.
BEAUTY IS ONLY SKIN DEEP! The attractive plumage of purple loosestrife conceals its menacing nature.
WHAT IS PURPLE LOOSESTRIFE? Purple loosestrife is an aquatic plant that is gaining a foothold. You may have seen the plant's magenta flowers which are strikingly evident throughout July and August. This hardy perennial has been introduced from Europe. Because of its exotic origin, loosestrife has left behind all of its natural enemies and multiplies with no checks or balances in North America.
WHAT IS THE MAJOR IMPACT? The plant aggressively crowds out the vegetation required by wildlife, while having no value for wildlife itself. For example, songbirds do not make use of the small hard seed. Muskrat require cattail to build their homes and they show a preference for cattail over loosestrife for food. Waterfowl, especially ducks, shun wetlands that have become dominated by loosestrife. In addition, overall waterfowl production is decreased as habitat is eliminated. Finally, the plant's growth is generally too compact to offer cover, and cover may be as crucial to wildlife as food.

Bugging Purple Loosestrife
An interesting article about combating purple loosestrife in central Washington state can be found at Excerpts from the story are included below.
Galerucella beetles
The beetles she was admiring were descendants of Galerucella beetles she had released in 1995 to combat purple loosestrife, an invasive wetland weed. A search for help led her to Bernd Blossey at Cornell University. Blossey supplied a "starter-kit" of insects, and Eberts began experimenting with ways to mass-produce the beetles. The resulting bugs were shipped to Craig Conley, who released them at the Wasteway in 1995.

Hylobius Weevil
Eberts cautioned that several years of defoliation are necessary to kill the plant, because this perennial weed has food reserves in its roots that can sustain it for several years. She plans to introduce another insect, a root-feeding weevil, to help deplete those reserves faster and kill more plants. Unfortunately, this weevil is slow to reproduce-taking up to 2 years from egg to adult. Cooperative research, between Reclamation and Cornell University, led to the development of a soon-to-be-patented laboratory diet that produces large numbers of healthy adult weevils in only 10 weeks.

Michigan Sea Grant Purple Pages - biological control of purple loosestrife

New Zealand Mud Snail

NOTE: West Denver Trout Unlimited recommends 100% strength "Commercial Solutions Formula 409® Cleaner Degreaser Disinfectant" - - after a recent Colorado study.
Portland State University Center for Lakes and Reservoirs and the U.S. Fishand Wildlife Service had recommended Formula 409 (50% diluted)
New Zealand Mud Snail brochure from Oregon State University Seagrant - download pdf
New Zealand Mud Snail website from the Santa Monica Bay Restoration Commission in Southern California -

The snails are very tiny and highly reproductive. The problem is created by their high numbers-billions of them-soon they cover every stone, log or other object in the water. In the process they will consume all the algae that other, more desirable trout stream invertebrates need to survive, including may flies, stone flies and caddis flies which are vital parts of the food chain. A collapse of the food chain will result in a collapse of the fishery. These snails can survive out of water on wading and fishing gear for extended periods. In addition, invasive plants and animals are known to hitchhike on boats and their propellers. As a general practice, washing and scrubbing your boat and its equipment, and allowing it to completely dry between uses will prevent the spread of zebra mussels and plants.

• Spray gear with Clorox Formula 409 - 100% strength per Denver Trout (see for the correct strength and which Formula 409 product), and then scrub with a stiff-bristled brush to remove all visible snails. Follow the procedure with a careful inspection of waders and gear to ensure the removal of all adult snails and finish with a tap-water rinse. Snails frequently collect between the laces and tongue of wading boots and in the boots' felt soles.
• Freeze waders for six to eight hours. It is best to leave them in the freezer overnight to ensure complete mortality.
• Dry gear in air temperatures over 112 degrees (50 degrees Celsius) for 24 hours to eliminate all mud snails. Alternatively, place gear in water maintained at 130 degrees for five minutes. Mortality of the snails varies at different combinations of heat and humidity.

For more information on NZMS contact the Federation of Fly Fishers at 406-222-9369.
For an identification description and pictures see Montana State University, Bozeman, Department of Ecology:

Quagga Mussels (Zebra Mussel's cousin - worse)

Not here yet, but be aware
1/07 - Quagga mussels are from the same genus as the more commonly known zebra mussel, but are slightly bigger. Douglas Karafa,  
  an administrator with the Clean Water Coalition, called the quagga "zebra's nasty cousin."                                
" They're just bigger," he said, "and they're worse." 
Found in Lake Havasu and Lake Mead's Boulder Basin and a state fish hatchery. and

Recreational water enthusiasts can call (866) 440-9530 to report seeing the mussel or to get information. Originally from Eastern Europe, quagga mussels and a related species, zebra mussels, have infested the Great Lakes, parts of the Mississippi River and other eastern bodies of water.

Invasive Species Information and Contacts

• Aquatic Nuisance Species Task Force -
• Invasive Species - A gateway to Federal and State invasive species activities and programs. Invasive Species Manager's Tool Kit - control Management Plans -
• Invasive and Exotic Species of North America -
• Oregon Department of Agriculture - Oregon Invasive Species Council -
• Oregon State University -
• Portland State University Center for Lakes and Reservoirs -
• Oregon Aquatic Nuisance Species Management Plan -
• Smithsonian Marine Invasion Research Lab -
• Washington Lake Protection Association (WALPA) -
• Western Aquatic Plant Management Society -
• Western Regional Panel on Aquatic Nuisance Species -
• 10/14/06 - “Aquatic Invaders” – an educational program that demonstrates simple steps to avoid the spread of invasive species – was honored by Coastal America during a recent national meeting of the Association of Zoos and Aquariums. See the Oregon State University website

Eurasian watermilfoil

Stop Aquatic Hitchhikers! Prevent the transport of nuisance species. Clean all recreational equipment. Be sure to play "Who wants to be a fish biologist?" (national Aquatic Nuisance Species Task Force, U.S. Fish and Wildlife Service) -   
It's Time to Come Clean (Oregon State Marine Board) -

Invasive Species Hotline - 1-866-468-2337 or 1-866-INVADER

Invasive Species Signs & Oregon Administrative Rules (OAR)

PADL received two signs from the Portland State University Center for Lakes and Reservoirs to place around the lake. 11/05
1) (Red and white) - Harmful Species - pictures New Zealand mudsnail, Hydrilla, Zebra mussel

Oregon Administrative Rules
OAR 635-056 and OAR 603-052-1200 on the sign
635-056-0000 -
Purpose and General Information - The purpose of these rules is to protect Oregon's native wildlife. These rules aim for this goal by regulating human actions involving nonnative wildlife (whether those actions involve trade in nonnative wildlife or involve interaction with nonnative species in the wild). The rules allow private use or ownership of nonnative species to the extent that they do not pose a significant risk of harm to native species.
603-052-1200 - Quarantine; Noxious Weeds

            (1) Establishing Quarantine. A quarantine is established against the noxious weeds listed herein. Noxious weeds have become so thoroughly established and are spreading so rapidly that they have been declared a menace to the public welfare. ORS 570.505.
            (2) Areas Under Quarantine. The entire state of Oregon and all other States of the United States and all foreign countries.
            (3) Covered Plants. For purposes of this rule the term "plants" applies to whole plants, plant parts, and seeds. This rule applies to all "A" and "B" designated noxious weeds listed herein, except as provided in subsections (c) and (d). Plants on the Federal Noxious Weed List (7 C.F.R. 360.200) are also covered by this rule, with the exception of Japanese blood grass, Imperata cylindrica, var. Red Baron and Chinese water spinach, Ipomoea aquatica.

2) (Gold) - New Zealand mudsnail - prevent the spread - Stop Aquatic Hitchhikers

PADL received one sign from the Oregon State University Hatfield Marine Science Center 7/05
1) (White) - Chinese Mitten Crab
PADL distributed the signs to City Parks for boat launch areas (Regatta Park, Holmes Road Park), DLWID and State Parks

Photo: Purple Loosestrife (USFWS)

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P.O. Box 36
Lincoln City, OR 97367