1. AQUATIC EXOTICS
Aquatic exotics are causing serious ecological and economic damage to our nation — damage that could be happening right in your own backyard. During this presentation you’ll learn about the problems these invasive fish, aquatic invertebrates, and aquatic plants are causing. You'll also learn what you can do to prevent their spread and limit their impacts. 1

2. Exxon Valdez Oil Spill Valdez, Alaska 1989
The invasion of aquatic exotic species has been likened to biological pollution, which in turn is similar to chemical pollution. Both cause huge amounts of damage, require treatment, and can spread beyond the initial point of release, like the Exxon Valdez oil spill in Unlike chemical pollution, though, biological pollution is forever.
In one of his speeches, former Senator John Glenn illustrated the comparison, “Picture a pollution spill in the waters of your region that simply won’t go away. Government and industry teams work to disperse it with chemicals and mechanical barriers, but as soon as the treatments stop, the pollution resurges. Worse yet, the spill spreads and concentrates in connecting waterways and is further seeded by unintentional transport overland. Municipalities, manufacturers, and agriculture experience degraded water supplies and higher operating costs. Shell-fisheries and fin-fisheries permanently decline. This scenario sounds like a nightmare, yet it closely approximates the result of unintentional release of nonindigenous species, or “biological pollution” into U.S. waters.”
Exxon Valdez Oil Spill
Valdez, Alaska 1989 2

3. “By the end of the 21st century, biological invasions will
become one of the most
prominent ecological
issues on Earth.”
OTA Report (1993)
This problem of biological pollution is happening on a global scale. This was highlighted in a 1993 report to the U.S. Congress by the Office of Technology Assessment, or OTA. The OTA predicted that “By the end of the 21st Century, biological invasions will become one of the most prominent ecological issues on Earth.” 3

4. OTA Report > 4,500 species established
> 205 species arrived since 1980
59 might cause damage
Control costs will approach $100 billion
According to that report, 4,500 aquatic and terrestrial species of foreign origin have established free-living U.S. populations. More than 205 species arrived since 1980, and 59 of these are expected to cause economic or environmental damage.
Another, more recent report by researchers at Cornell University estimates that control costs for invasive terrestrial and aquatic species exceed 138 billion dollars annually. 4

5. Infestations Are Increasing
Not only have we been invaded by thousands of species, there is evidence that the infestation rate is increasing. The OTA report shows that the rate of fish introductions has dramatically increased since 1950, while the rate of introductions of mollusks or clams began increasing earlier, in the 1920s. Few of these invaders found their way to North America on their own. Instead, they were introduced either purposefully or accidentally by people through a number of pathways. 5

6. Interrupt the Pathways
Shipping and barge traffic
Aquaculture and public stocking
Wild bait harvest
Recreational boats
Live bait
Nursery trade and aquascaping
Aquarium and pet trade
Our challenge is to interrupt the pathways of introduction. These pathways include: commercial shipping and barge traffic, researchers, aquaculture, public stocking, wild bait harvest, recreational boats and personal watercraft, live bait use by anglers, the nursery trade, aquascaping, aquarium releases, and the pet trade. 6

7. Great Lakes Exotics Purple loosestrife Zebra mussel Quagga mussel
Spiny waterflea
Fishhook waterflea
Eurasian ruffe
Round goby
Alewife
Trout and salmon
Some exotic species in the Great Lakes that arrived through these pathways include purple loosestrife, zebra and quagga mussels, waterfleas, Eurasian ruffe, round goby, alewife; chinook, coho, pink and Atlantic salmon; and rainbow and brown trout. In fact, over the last two centuries, more than 139 exotic species have been introduced into the Great Lakes through these pathways. 7

8. Where Did They Come From?
Eurasia
Atlantic
Asia
Mississippi
Pacific/Southern U.S. 7
Unknown
Total:
Of the 139 exotics, 77 are from Eurasia, 18 are from the Atlantic Ocean, 12 are from Asia, 7 are from the Mississippi River basin, another 7 are from the Pacific and southern U.S., and there were 18 whose origin could not be documented.
(data taken from Mills et al. 1993) 8

9. Unintentional release 40
How Did They Get Here?
Ships
Unintentional release 40
Multiple
Unknown
Deliberate release 11
Canals
Railroad/Highway 1
How did these species get here? The largest portion of these was introduced by ships, followed by unintentional releases, multiple releases, unknown sources, deliberate releases, canals and diversions, and railroads and highways. 9
(data taken from Mills et al. 1993)

10. What Are They? % of Species Plants (mostly marsh) 42 Invertebrates 21
Fish
Algae
Fish pathogens 2
What kinds of species have been introduced? Wetland plants rank first, followed by invertebrates, fish, algae, and fish pathogens. And, since this research was published, the Great Lakes have witnessed more introductions bringing the total number to over 160 species. 10
(data taken from Mills et al. 1993)

11. Why Do Exotics Cause Problems?
Aggressive and prolific
Mature quickly
Leave behind diseases, parasites, predators, and competitors
This Far Side cartoon by Gary Larson helps emphasize a point about "biological pollution." It says: “Well shucks! I’ve lost again. Talk about your alien species luck!” But, biological invaders are not just lucky. Often, they have attributes that give them a competitive advantage over our native species. They are usually aggressive and prolific species that mature quickly. They frequently leave behind diseases, parasites, predators, competitors, and other factors that keep the populations in their native ranges in check. Because they’re kept in check, these species usually are not a problem in their native habitat. 11

12. The Good The Bad The Ugly
In their new habitat, introduced species can be characterized as being good, bad, or ugly. Some species either have no impact or are considered to be beneficial. Those are the good. The bad species have a definite negative impact in their new habitat. And, ugly species are those that may have a significant negative impact in the future, but aren’t yet a definite problem. 12

13. The Good
First, we’ll start with the good – those species that have been introduced and are beneficial in some ways.
Pheasants are exotic species, but provide hunting or bird watching enjoyment. In the Great Lakes, most of the trout and salmon species are also introduced, but support charter and recreational fishing. Other exotics, like honeybees, provide benefits to agriculture.
It is sometimes difficult to distinguish between a "good" and a "bad" exotic species because many exotics have both positive and negative effects. Without question, however, many are “bad.” We know that they have a definite negative impact. 13

14. The Bad
The poster child for “bad” aquatic exotic species is the zebra mussel. Zebra mussels and their cousins, quagga mussels, change the way we use our lakes and rivers. In many systems, they have had costly and devastating impacts. 14

15. Veliger Adult Can produce up to 1.6 M eggs/yr! 15
Zebra mussels are small, bivalve mollusks — bivalve meaning that there are two halves to its shell. They’re prolific creatures. A mature female can produce from 30 thousand to 1.6 million eggs per year. During spawning, the water can be so thick with zebra mussel larvae, called veligers, that there could be more than 100 in a coffee cup scoop of water. These veligers are about the diameter of a human hair, and drift on water currents.
Can produce up to 1.6 M eggs/yr! 15

16. Two to four weeks after hatching, the free-swimming larvae settle and attach to any solid object, including each other. If they attach to movable objects, such as a boat, they can be spread to other waterways.
Zebra mussel colony 16

17. Byssal
threads
Zebra mussels attach to surfaces by secreting sticky fibers, called byssal threads. A single, tiny zebra mussel poses no threat….. 17

18. 18 but they are rarely found as scattered individuals.
Given the right conditions, they can appear by the billions and form thick carpets that can cover lake and river bottoms. 18

19. Impacts of Zebra Mussels
The impacts of zebra mussels are varied. One type of impact results from their feeding. Adults feed by drawing water into their bodies, and then filtering and consuming the suspended particles that are in that water. Each adult mussel filters about one liter of water per day. Based on zebra mussel densities in the western basin of Lake Erie, experts calculate that zebra mussels filter all of the water in the basin once every three days.
Feed by filtering particles from water
Each adult can filter 1 L water/day 19

20. Impacts of Zebra Mussels
Zebra mussel filtering may improve water clarity and make the water nicer to look at, but it alters plant and animal communities. For example, in lakes Erie and St. Clair, rooted aquatic plants have become established in areas where they have been absent for a long time. In other areas, aquatic plants have grown more densely than usual, and have extended into deeper waters because of increased light penetration. Aquatic plants now choke many marinas, boat basins, and harbors in the Great Lakes.
Also, scientists believe that through their feeding, zebra mussels are disrupting the food web, leading to the decline of sport and commercial fisheries.
Increase weed growth
Disrupt food webs 20

21. Impacts of Zebra Mussels
Zebra mussels can also impact boaters and shore land property owners. They can attach to boat hulls, clog boat engine cooling systems, and clog water intakes. Scraping off the zebra mussels from an encrusted hull can damage the boat’s paint or gel coat. By growing in an engine cooling system, they can block water flow, which can cause the engine to overheat. If you own shoreline property and draw water from an infested lake or river, they can also clog your pumps and hoses, making them inoperative.
Fouled boat
Clogged pipe 21

22. Impacts of Zebra Mussels
In much the same way, zebra mussels also affect industries and municipalities that draw water from the Great Lakes. These entities have several effective ways to control zebra mussels, but controlling zebra mussels is costly. In fact, these costs may already be adding to your monthly utility bills.
For example, from 1989 to 1994, zebra mussel control costs for industries and municipalities around the Great Lakes were an estimated 120 million dollars. An individual, medium-size city can spend 360,000 dollars annually. A nuclear power plant can spend up to 2 million dollars annually.
Control costs in the Great Lakes = $120 million from 22

23. Impacts of Zebra Mussels
And, because of the densities they’re able to achieve, zebra mussels can cause a clean, sandy beach to turn into… 23

24. a beach littered with piles of decaying flesh and sharp shells, which can restrict swimming and wading. 24

25. Spread as larvae and adults Only 10 states with inland infested waters
Zebra Mussel
Distribution
Spread as larvae and adults
Only 10 states with inland infested waters
Zebra mussels can spread relatively easily. They can spread as microscopic larvae in containers of surface water. They can also spread as adults on boat hulls and aquatic plants that become entangled on recreational boat motors and trailers. Given this, it’s remarkable that they haven’t spread any farther than they have. In fact, as of June 2001, they had only spread to inland lakes in ten states. Most of these are within a short distance of the Great Lakes.
(WI, MI, MN, PA, IL, IN, OH, NY, CT, VT) 25

26. Lakes Erie, Ontario and Michigan Ohio and Mississippi rivers
Quagga Mussel Distribution
Lakes Erie, Ontario and Michigan
Ohio and Mississippi rivers
The cousin of the zebra mussel, the quagga mussel is also spreading. While they seem to prefer colder, deeper areas of lakes Erie, Ontario, and Michigan, they have also spread to the Ohio and Mississippi rivers. They’re even out-competing zebra mussels in the Erie Canal and in shallow areas of the Great Lakes.
(WI, MI, IL, IN, OH, NY, CT, VT) 26

27. ID and Early Detection Newly settled mussels feel like fine sand paper
Identification and early detection are important to preventing the spread of all of the exotics that we’ll talk about.
For zebra and quagga mussels, newly settled individuals feel like fine sandpaper on smooth surfaces, such as a boat hull. As they grow, they look like coarse grains of pepper. During the next stage, they begin to take on their characteristic brown to black striping.
Newly settled mussels feel like fine sand paper
Grow to look like coarse grains of pepper 27

28. Industrial control is costly
Cause serious damage
Industrial control is costly
No method of control in natural ecosystems
Preventing the spread is critical
Zebra mussels cause serious ecological and economic damage to areas they infest. Industries and municipalities have effective control methods to keep zebra mussels from clogging pipes, but those methods cost us all a lot of money. Since there is no method to control zebra mussels in natural aquatic ecosystems, preventing their spread is critical. 28

29. Rusty Crayfish Replaces native crayfish Competes with fish
Another “bad” invader is the rusty crayfish, an aggressive species that can replace native crayfish. It also competes for food with juvenile game and forage fish, raids fish nests for eggs, and has nearly eradicated aquatic plants in some northern lakes. This loss of plants results in a loss of fish habitat and possibly greater shoreline erosion.
Replaces native crayfish
Competes with fish
Raids fish nests
Eradicates aquatic plants 29

30. U.S. Distribution 30 Drainages with native populations
Where did they come from? The native range of the rusty crayfish encompasses the Ohio River basin. Currently, they are found in all of the Great Lakes states, and have spread to inland lakes in the Midwest, New England, Tennessee, and New Mexico.
Drainages with native populations
Drainages with introduced populations 30

31. Rusty Crayfish Spread Anglers and commercial harvesters Ballast water
How have they spread? Rusty crayfish most likely spread by:
anglers using live rusty crayfish as bait,
commercial harvesters,
ballast water, and
biological supply houses, which provide live specimens for study by teachers and students.
Their life history facilitates their spread. Like most crayfish, mating typically occurs in the fall and the female stores the sperm until she releases the eggs in the spring. Therefore, one female rusty can populate a whole new area by herself — males need not be present.
Anglers and commercial harvesters
Ballast water
Biological supply houses & schools
Life history facilitates spread 31

32. Rusty Crayfish ID Can grow up to 8 in Rust spots on carapace
Distinguishing a rusty crayfish from native species can be difficult. Adult rusty crayfish can be much larger than our native crayfish – up to eight inches long from claw to tail. The main distinguishing characteristic is the rust-colored spots on its shell or carapace. They look as if they have been picked-up by someone with rust-colored paint on their thumb and forefinger. Also, their large claws are grayish-green to red-brown with black tips. These characteristics only apply to mature adult males. Juveniles are difficult to distinguish from native species, so identifications should always be confirmed.
Can grow up to 8 in
Rust spots on carapace
Large gray-green/red-brown claws 32

33. Rusty Crayfish No environmentally-friendly control method
Because they are similar to native crayfish in terms of biology and life history, there is no known environmentally friendly method of control for rusty crayfish. Therefore, preventing their spread is again critical.
No environmentally-friendly control method
Preventing the spread is critical 33

34. Round Goby Small, strange-looking bottom fish
Another bad invader is this small, strange-looking, bottom fish called the round goby. It also came into the Great Lakes in ballast water and is now considered a nuisance by anglers.
Small, strange-looking bottom fish
Came from Eurasia in ballast water
Considered a nuisance by anglers 34

35. Round Goby Impacts Out-compete native species
mottled
sculpin
A round goby can spawn up to 6 times per year and produce 500 to 5,200 eggs per spawning period. It is a very aggressive fish and can feed during both day and night. Because of these characteristics, it can out-compete native, bottom-dwelling species, such as the mottled sculpin, for food and spawning sites. These attributes also allow them to quickly dominate local fisheries.
Out-compete native species
Quickly dominate local fisheries 35

36. Round Goby Impacts Feed on lake trout and sturgeon eggs 36
In addition to their impacts on bottom-dwelling forage fish, round gobies could possibly impact lake trout and sturgeon by feeding on their eggs. This could spell additional trouble for revitalization of these fisheries throughout the Great Lakes.
Feed on lake trout and sturgeon eggs 36

37. First found in the St. Clair River in 1990, the round goby quickly spread to parts of all of the Great Lakes via inter-lake and intra-lake ballast water discharge. No inland lakes are infested, but two Michigan rivers have gobies, which were probably introduced by anglers using the goby as bait. They’ve also spread downstream into the Chicago Waterways en route to the Mississippi River. 37

38. Round Goby Identification
Round gobies are easy to identify. There is no other fish in the Great Lakes whose pelvic fins are fused except its cousin the tubenose goby, which is also an exotic.
This fin basically looks like someone took half of a clam shell and stuck it to the fish’s belly. Gobies can use this disc like a suction cup to anchor to the bottom of rivers and streams.
Fused pelvic fins 38

39. Eurasian Watermilfoil
The last “bad” invader that we’ll address is Eurasian watermilfoil. Eurasian watermilfoil is a highly invasive, submerged, aquatic plant that forms dense mats. It replaces native plants, and degrades food, shelter, and nesting sites for fish. Dense mats, as shown here, can clog waterways and limit swimming and boating.
Forms dense mats
Replaces native plants
Degrades food, shelter, and nesting sites for fish
Limits swimming and boating 39

40. Eurasian Watermilfoil Spreads by fragmentation
The main way that Eurasian watermilfoil spreads is by fragmentation. A two-inch long fragment can be carried in water currents to another location, and begin a new infestation.
Spreads by fragmentation 40

41. Eurasian Watermilfoil
While it can spread naturally in connected waters, Eurasian watermilfoil is primarily spread when it becomes entangled on powerboats, sailboats, and personal watercraft that are then launched in other waterways.
Can be spread by recreational water users 41

42. U.S. Distribution States with nonnative records 42
Where did it come from and where is it now? As its name implies, Eurasian watermilfoil is native to Europe and Asia. It first appeared on the East Coast and subsequently spread throughout the continental U.S., except for Maine.
Adapted 1999 from
USGS-Gainesville
States with nonnative records 42

43. Optimistic News Traditional control methods costly
Historically, natural resource management agencies have controlled Eurasian watermilfoil by using herbicides and mechanical harvesting, both of which harm native plants, are expensive, and are time consuming.
However, there is some optimistic news for the future. Research has shown that a North American species of weevil feeds on Eurasian watermilfoil stems. Their feeding can cause the stems to droop and fall to the lake bottom. While it is unlikely that the weevils will eradicate infestations, under certain conditions, the weevils have reduced the canopy formed by Eurasian watermilfoil. This improves the opportunities for both native plant diversity and recreation.
Traditional control methods costly
Native weevil feeds on Eurasian watermilfoil
Can cause stems to fall to lake bottom
Reduces canopy 43

44. Spiny Waterflea Predaceous zooplankton
Now, moving from the “bad” to the “ugly” – again, those species that haven’t yet had a definite impact, but might in the future.
There is an invasive species that’s even smaller than the zebra mussel called the spiny waterflea, Bythotrephes cederstroemi, or BC. BC is a type of zooplankton, which are tiny animals that live suspended in the water of lakes and rivers. BC is a predator that grows only to about three-eighths of an inch long.
This invader can impact fisheries by eating smaller zooplankton, which are important food resources for juvenile and forage fish. In southern Lake Michigan and inland lakes in Ontario, scientists partially blame the spiny water flea for a decline in and sometimes localized extirpation of small, native zooplankton.
Spiny waterfleass seem to prefer larger lakes with open waters that stratify. This allows them to stay near the thermocline during the day, avoiding sunlight and predation.
Predaceous zooplankton
Causes declines in native zooplankton
May impact fisheries 44

45. BC was first found in Lake Huron in 1984
BC was first found in Lake Huron in Within the next three years it had spread to all of the Great Lakes. It has since spread to more than thirty inland lakes in Minnesota, Michigan, and southern Ontario, most likely by boaters and anglers. 45

46. Boaters and anglers can transport BC, but can also be the first to discover new infestations. That’s because BC can easily get caught on fishing lines and downrigger cables. This picture shows 40 to 50 female spiny waterfleass entangled on a downrigger cable. 46

47. Fishhook waterflea
The spiny waterflea has an invasive cousin called the fishhook waterflea or Cercopagis pengoi.
The fishhook waterflea is slightly longer, about a half-inch long, and has a spiny tail that meets the body at a 90 degree angle. It also has a characteristic corkscrew or fishhook bend near the end of its tail, which gives it its name.
This invader was first found in Lake Ontario in It quickly spread east to west across the lake, and has since spread to Lake Michigan and several Finger Lakes in New York.
Because the fishhook waterflea is a relatively new invader, we don’t yet know what ecosystem impacts it will have. It’s suspected that it also will reduce numbers of native zooplankton. It’s already become a nuisance to anglers by fouling downrigger cables and fishing lines, and clogging fishing reels. 47

48. Arrived in mid 1980s via ballast water
Eurasian Ruffe
Lake Superior was ground zero for the North American invasion of the Eurasian ruffe. This spiny fish first arrived in Duluth-Superior Harbor in the mid-1980s via ballast. By 1991, ruffe had become the most abundant fish in the harbor. Despite efforts to manage it by stocking predatory fish, the ruffe infestation grew to over six million by 1996, and remains high today.
Arrived in mid 1980s via ballast water 48

49. Spawn 2 – 3 times/season Mature rapidly Feed during day and night
Eurasian Ruffe
Concurrent decreases in forage fish and yellow perch in Duluth-Superior Harbor raised concerns over the infestation’s impacts on native fish. Because ruffe can spawn two to three times per season, mature rapidly, and feed during the day and at night, they have the ability to compete with and displace our native fish.
Spawn 2 – 3 times/season
Mature rapidly
Feed during day and night 49

50. Eurasian Ruffe Impacts
One native fish of particular concern is yellow perch. Researchers have demonstrated that yellow perch grow more slowly in the presence of ruffe, and that their diets overlap significantly. Elsewhere in Lake Superior, however, downward trends in yellow perch and shiner populations in the absence of ruffe suggest that native fish in Duluth-Superior Harbor might have problems that are not due to ruffe alone.
May compete with yellow perch 50

51. Great Lakes-wide infestation is estimated at $105 million annually
Predicted impacts of
Great Lakes-wide infestation is
estimated at $105 million annually
Ruffe may have a significant impact on native fishes if it spreads to other, more productive waters like Lake Erie or inland lakes and rivers. The National Oceanic and Atmospheric Administration predicted that a moderate-level, Great Lakes-wide infestation would have an estimated 105 million dollar annual impact on the fisheries. 51

52. *
Currently, ruffe have spread north to three harbors along the north shore and all along the south shore of Lake Superior to just past Ontonagon, Michigan. In 1995, they were also found in Lake Huron at Alpena, Michigan, which was probably a ballast water introduction from the Duluth-Superior Harbor.
The good news is that ruffe have not spread significantly since then, and there are no inland lakes or rivers with confirmed sightings. Much of the success in preventing new infestations of ruffe is due to public awareness. Anglers know that ruffe are bad, and are not using or transporting them to inland waters as bait. This is doubly good since it is illegal to use ruffe as bait in all Great Lakes states, Ontario, and Quebec. 52

53. White Perch Native to Atlantic coast Found in all Great Lakes
Another ugly fish is the white perch. White perch are native to brackish waters along the Atlantic coast. They were first found in Lake Erie in 1953, and since then have become the second most abundant species in the western basin of the lake. Now found in all of the Great Lakes, white perch feed mainly on zooplankton, large invertebrates, and small fish. They tend to prefer shallow areas, such as river mouths, bays, reefs, and nearshore areas.
Native to Atlantic coast
Found in all Great Lakes
Feed on zooplankton, invertebrates, and fish
Prefer shallow areas 53

54. White Perch white perch white bass
White perch are easily confused with white bass, which are native to some of the Great Lakes. The white bass is distinguished by the dark, horizontal stripes on its back and sides. White perch are commonly caught by anglers and are harvested commercially from Lake Erie. Possibly transported with drum and shiners, white perch now infest several inland watersheds in Ohio.
Easily confused with native white bass
Transported to several inland lakes in Ohio 54

55. White Perch Can grow up to 10” long
In some areas of the Great Lakes, white perch can grow up to ten inches long. However, where populations are high, they are commonly stunted and mostly undesirable to anglers. In polluted areas, white perch exceed allowable PCB tissue residues, and thus are prohibited from sale for human consumption.
Can grow up to 10” long
Commonly stunted and undesired by anglers
Can have high levels of PCBs 55

56. Threespine Stickleback
The threespine stickleback is a “bug-eyed” exotic fish that is causing concern over its rapid spread and potential impacts. Its natural range includes Hudson Bay, the Atlantic coast, and Lake Ontario. Since 1980, it has spread to lakes Superior, Michigan, and Huron, probably through ballast water discharge, and water diversions and canals. While we know something about its spread, little is known about its potential impacts.
Native to Hudson Bay, the Atlantic coast, and Lake Ontario
Spread to lakes Superior, Michigan, and Huron
Little known about potential impacts 56

57. Threespine Stickleback
Fourspine Stickleback
May compete with native sticklebacks
3 or 4 spines on dorsal fin, respectively
Native sticklebacks have 5 or more spines on dorsal fin
There is concern, though, that the threespine stickleback and its exotic cousin, the fourspine stickleback, may compete with native sticklebacks because their diets overlap.
These fish are easy to identify — there are three or four spines on the dorsal fin. Basically they look like bug-eyed fish with a bad haircut. Our native sticklebacks have five or more spines on their dorsal fins. 57

58. Purple Loosestrife Perennial from Europe Invades moist areas
In contrast to these ugly invaders, there is a beautiful one called purple loosestrife. Purple loosestrife is an invasive, perennial plant from Europe. It has spread across North American wetlands, lakeshores, roadside ditches, and other moist areas.
But while it’s beautiful, it’s also devastating. In habitats that it invades, it forms dense stands and crowds out native plants. This reduces food, shelter, and nesting opportunities for wildlife, which leads to an overall decrease in biodiversity.
Perennial from Europe
Invades moist areas
Crowds out natives—reduces biodiversity 58

59. Biological Invasions by GLP
U.S. Distribution
Purple loosestife first arrived on the East Coast in the 1800s via solid ballast soil and settlers who brought the seeds to plant in their gardens. It has since invaded nearly the entire continental U.S. Each plant can produce over two million seeds per year that spread by wind and water currents. In addition, its seeds are often distributed in wild seed mixtures, and the plant is often used in flower gardens. This occurs despite the fact that many states have made it illegal to plant or propagate purple loosestrife.
Traditional methods of control include hand pulling, spot treatment with herbicides, burning, mowing, and public education aimed at prevention. However, many states are adopting a new management technique.
Adapted 1999 from
Biological Invasions by GLP 59

60. Good News!! 5 species approved for release Galerucella weevil
Feeds on leaves and growing shoots
Defoliates, reduces flowering, can kill plant
Releases could reduce loosestrife by 80-90%
This technique involves five species of European insects that have undergone rigorous experimentation by the U.S. Department of Agriculture, and are approved for release. The most commonly used is a weevil, called Galerucella, which feeds on the plant’s leaves and growing shoots. Feeding by the weevil defoliates the plant, reduces or eliminates flowering, and in many cases ultimately kills the plant.
The U.S. Fish and Wildlife Service predicts that Galerucella releases could reduce purple loosestrife in North America by 80 to 90% over the next 15 to 20 years. Like the Eurasian watermilfoil weevil, the release of this biocontrol agent is not intended to eradicate purple loosestrife. Instead, it is intended to reduce purple loosestrife to manageable levels that will allow native plants to re-colonize and thrive again. 60

61. We can make a difference!
Despite all this “doom and gloom” about invasive species impacting our lives and our natural resources, people can and are working to prevent their spread. 61

62. Three-State Exotic Species Boater Survey
How best to reach boaters
Determine if boaters taking action
Research has shown that boaters and anglers have contributed to the spread of aquatic exotic species. But, the good news is that education can help reduce the risk for spread. A survey conducted by Minnesota Sea Grant in 1994 shows that most boaters across Minnesota, Wisconsin, and Ohio understand that preventing the spread of aquatic exotics is important.
Part of the purpose of this survey was to 1) find out how to best reach boaters with the most effective message, and 2) determine whether they are taking action based on this knowledge. 62

63. Source For Exotics Information
Minn
Wisc
Ohio
Newspaper
Television
Magazine
Boat Launch
Here is where boaters said they get their information on exotics. All of them overwhelmingly said newspapers and TV – usually 80% or better. People also ranked signs at boat launches highly, second only to newspapers and TV. Magazines also ranked high. 63

64. How Effective Are The Following?
Minn
Wisc
Ohio
Highest Ranked
Signs at Accesses
In Fish/Boat Regs
Brochures
Inspection/Ed
Lowest Ranked
Laws
Road Checks
The boaters were asked, “How effective are each of the following to get you to take steps to prevent the spread of aquatic exotics?” Boaters responded that signs at boat accesses, information in fishing and boating booklets, brochures and pamphlets, and education inspections were very effective. Ranking lowest were laws and road checks. It was obvious that folks don’t like them. However, they have been shown to be effective tools in some states. 64

65. What Influenced You Most?
Minn
Wisc
Ohio
Out of “My” Lake
Personal Responsibility
Signs at Access
Prevent Property Damage
They were next asked, “What influences boaters most?” Keeping them out of “MY” lake or river, signs at boat accesses, a sense of personal responsibility, and preventing damage were all very influential.
These responses indicate that boaters and anglers are open to education, and that that these feelings should be tapped into for future educational campaigns. 65

66. Why Didn’t You Take Precautions?
Not a Problem
Didn’t Boat in Infested Waters
Didn’t Know What To Do
Didn’t Have Time
If they didn’t take action to prevent the spread of aquatic exotics, they were asked “Why not?” Most responded that they didn’t boat in infested waters, or that they didn’t know what to do.
It Won’t Help
Percent response 66

67. What Works?
So, boater education is key. The best outlets for aquatic exotics information is TV, radio, newspapers, public service announcements, water access signs, fact sheets, cards, regulations booklets, watercraft inspections, regulations prohibiting spread, and billboards. 67

68. Survey Conclusions Boater education changes behavior
Boaters believe it is important to prevent the spread of aquatic exotics
Best information outlets are media, access signs, brochures, fishing and boating pamphlets
Educational efforts must continue
Overall…
boater education changes behavior,
boaters believe it is important to prevent the spread of aquatic exotics,
prime information outlets are the media, access signs, brochures, fishing and boating pamphlets,
and, educational efforts must continue. 68

69. Education Works
Rate of inland lake zebra mussel infestations is slowing
Eurasian watermilfoil infestation rate has slowed
Eurasian ruffe have not spread to inland lakes
Round goby spread to inland waters is limited
Education works. Nationally, the rate of inland lake zebra mussel infestations is slowing, and the infestations are limited to inland lakes in just ten states. They have not spread as far as they easily could have. In some states, where Eurasian watermilfoil public prevention is stressed, the infestation rate has dramatically slowed. Also, Eurasian ruffe have been in Lake Superior since 1986, yet there are no inland lake infestations. Likewise, the round goby has been in the Great Lakes for over a decade, but has not spread to many inland waterways. 69

70. Prevent the Spread Know how to identify exotics
Know which waters are infested
Know the laws concerning prohibited exotics
Learn the five simple steps to prevent spread
Recreational water users and shoreline property owners can prevent the spread of aquatic exotics. Know how to identify exotics and which waters are infested. Know the laws concerning prohibited exotics. And, learn the five simple steps to prevent the spread of aquatic exotic species. 70

71. BEFORE launching….. BEFORE leaving
Prevent the Spread
BEFORE launching….. BEFORE leaving
Remove aquatic plants and animals.
Drain lake or river water.
Dispose of unwanted live bait.
Rinse equipment with high pressure or 104 F water OR
Dry everything for at least 5 days.
Follow these steps before launching and before leaving any water access:
1.      Remove aquatic plants and animals from your boat, motor, and trailer.
2.      Drain lake or river water from bait bucket, live wells, and bilge.
3.      Dispose of unwanted live bait on shore or in the trash.
4.      Rinse boat and equipment with high pressure or 104 degree Fahrenheit water, especially if moored for more than a day.
5.      Or, dry all equipment for at least 5 days under good drying conditions
By taking a few moments to do these easy steps, you will help protect your property and our valuable water resources. 71

72. This presentation highlighted a few of the “least wanted” aquatic exotic species that have made the Great Lakes and some inland waters their home. There are many other invaders on our doorstep.
Your help is vital to keeping them out of our water resources. Report any suspicious sightings of aquatic plants or animals to your state Sea Grant program, natural resources management agency, or the U.S. Fish and Wildlife Service. Each year, reports from the public provide valuable information concerning spread of aquatic exotic species.
Whether it is the Great Lakes or any other waters, the establishment of each aquatic exotic species causes ripple effects across the food web. These effects can be felt by everyone from industry, to the every day boater, to the tax payer. And rarely, if ever, is it possible to eradicate an aquatic exotic infestation from a natural ecosystem. That's why prevention is so important.
Aquatic exotics are a major problem in and threat to our water resources. Thus, they deserve our earnest attention. 72

73. Written and produced by Doug Jensen and Jeff Gunderson 2001
With support from:
Editors: Glenn Kreag, Sharon Moen, Marie Zhuikov, and Pat Charlebois
Digital Production Coordinator: Debbie Bowen
Funding for this project was provided by a grant from the U.S. National Oceanic Administration to the National Sea Grant College Program through an appropriation by Congress based on the National Invasive Species Act of 1996. 73