Non-native Species Found in Lake Superior since 1883
Why Are They Here?
| Introduction | Number of Species | Percent |
|---|---|---|
| Unintentional | 47 | 55 |
| Unknown | 19 | 22 |
| Intentional | 21 | 24 |
How Are They Getting Here?
| Mechanism | Number of Species | Percent1 |
|---|---|---|
| Ballast Water Discharge | 30 | 35 |
| Cultivation | 19 | 22 |
| Stocked Fish | 12 | 13 |
| Unknown | 9 | 10 |
| Diseases and Parasites with Fish | 9 | 10 |
| Canals and Diversions | 6 | 7 |
| Aquarium Releases | 4 | 5 |
| Live Bait Releases by Anglers | 3 | 3 |
| Recreational Boaters | 2 | 2 |
| Railroads and Highways | 1 | 1 |
| Packaging Hitchhiker | 1 | 1 |
| Other Release | 1 | 1 |
1exceeds 100% since six species arrived via multiple pathways
List of Species
| Species | Scientific Name | Earliest Record | Earliest Location | Unintentional or Intentional | Transport or Release Mechanism(s) |
|---|---|---|---|---|---|
| Fish: (n=25, 29%) | |||||
| Alewife | Alosa pseudoharengus | <1953 | E. Lake Superior | Unintentional | Canals |
| American eel | Anguilla rostrata | 1970 | Brule River, WI | Unintentional | Canals |
| Atlantic salmon | Salmo salar | 1972 | Lake Superior, WI | Intentional | Stocked |
| Brown trout | Salmo trutta | 1883 | Lake Superior, MI | Intentional | Stocked |
| Brook silverside | Labidesthes sicculus | 2002 | St. Louis River | Unintentional | Unknown |
| Chinook salmon | Oncorhynchus tshawytscha | 1967 | Lake Superior, MI | Intentional | Stocked |
| Coho salmon | Oncorhynchus kisutch | 1966 | Lake Superior, MI | Intentional | Stocked |
| Common carp | Cyprinus carpio | 1897 | Lake Superior, WI | Intentional | Stocked |
| Eurasian ruffe | Gymnocephalus cernuus | 1986 | St. Louis River | Unintentional | Ballast Water |
| European flounder | Platichthys flesus | 1981 | Keweenaw Peninsula, MI | Unintentional | Ballast Water |
| Fourspine stickleback | Apeltes quadracus | 1986 | Thunder Bay, ON | Unintentional | Ballast Water or Live Bait |
| Freshwater drum | Aplodinotus grunniens | ? | ? | Intentional | Stocked (assumed) |
| Gizzard shad | Dorosoma cepedianum | ? | ? | Unintentional | Live Bait or Aquaria |
| Goldfish | Carassius auratus | 1975 | St. Louis River | Intentional | Stocked (assumed) |
| Kokanee salmon | Oncorhynchus nerka | ? | ? | Intentional | Stocked (assumed) |
| Pink salmon | Oncorhynchus gorbuscha | 1956 | Thunder Bay, ON | Intentional (unplanned) | Stocked |
| Rainbow smelt | Osmerus mordax | 1930 | Whitefish Bay, E. Lake Superior | Unintentional | Canals |
| Rainbow trout | Oncorhynchus mykiss | 1895 | W. Lake Superior | Intentional | Stocked |
| Round Goby | Apollonia melanostomus | 1995 | St. Louis River | Unintentional | Ballast Water |
| Sea lamprey | Petromyzon marinus | 1938 | Two Harbors, MN | Unintentional | Canals |
| Splake | Salveninus fontinalis x S. namaycush | ? | ? | Intentional | Stocked |
| Threespine stickleback | Gasterosteus aculeatus | 1987 | Thunder Bay, ON | Unintentional | Ballast Water |
| Tubenose goby | Proterorhinus semilunaris | 2000 | St. Louis River | Unintentional | Ballast Water |
| White Perch | Morone Americana | 1986 | St. Louis River | Unintentional | Ballast Water |
| Aquatic Invertebrates: (n=21, 24%) | |||||
| Aquatic oligochaete | Ripistes parasita | 1987 | Thunder Bay, ON | Unintentional | Ballast Water |
| Aquatic oligochaete | Vejdovskyella intermedia | 1980 | Unknown | Unintentional | Ballast Water? |
| Asian clam | Corbicula fluminea | 1999 | St. Louis River | Unintentional | Ballast Water |
| Bosmonid waterflea | Eubosmina coregoni | 1970s | Unknown | Unintentional | Ballast Water |
| Calanoid copepod | Eurytemora affinis | 1960s | Unknown | Unintentional | Ballast Water |
| Cyclopoid copepod | Cyclops strenuous | ? | ? | Unintentional | Ballast Water? |
| European valve snail | Valvata piscinalis | 1985? | St. Louis River | Unintentional | Ballast Water or Aquaria |
| Faucet snail | Bithynia tentaculata | 2005 | St. Louis River | Unintentional | Ballast Water or Aquaria |
| Gammarid amphipod | Echinogammarus ischnus | 2001 | Thunder Bay, ON | Unintentional | Ballast Water, Packaging or Other Release |
| Gammarid amphipod | Gammarus fasciatus | 2001 | Widespread | Unintentional | Ballast Water |
| Greater European pea clam | Pisidium amnicum | 1985? | St. Louis River | Unintentional | Ballast (Solid)? |
| Henslows pea clam | Pisidium henslowanum | 2005 | St. Louis River | Unintentional | Ballast Water? |
| Hump-backed pea clam | Pisidium supinum | 2005 | St. Louis River | Unintentional | Ballast Water? |
| Lumholtzs waterflea | Daphnia lumholtzi | 2005 | St. Louis River | Unintentional | Ballast Water? |
| Moitessiers pea clam | Pisidium moitessierianum | 1985? | St. Louis River | Unintentional | Ballast Water? |
| New Zealand mudsnail | Potamopyrgus antipodarum | 2001 | Thunder Bay, ON | Unintentional | Ballast Water |
| Quagga mussel | Dreissena bugensis | 2005 | St. Louis River | Unintentional | Ballast Water |
| Rusty crayfish | Orconectes rusticus | 1991 | Thunder Bay, ON | Unintentional | Ballast Water, Live Bait, or Aquaria |
| Spiny waterflea | Bythotrephes longimanus | 1987 | E. Lake Superior, ON | Unintentional | Ballast Water |
| Tiger sideswimmer | Gammarus tigrinus | 1985?/td> | St. Louis River | Unintentional | Ballast Water |
| Zebra Mussel | Breissena polymorpha | 1989 | St. Louis River | Unintentional | Ballast Water |
| Diseases & Parasites: (n=9, 11%) | |||||
| Bacterial kidney disease | Corynebacterium ssp. | <1975 | Not Available | Unintentional | Fish disease |
| Furunculosis | Aeromonas salmonicida | Unknown | Unknown | Unintentional | Fish disease |
| Parasite (microsporidian) | Glugea herwigi | 1930s | Unknown | Unintentional | Fish parasite |
| Whirling disease | Myxobolus cerebralis | Unknown | Unknown | Unintentional | Fish disease |
| Parasite | Sphaeromyxa sevastopoli | 1995 | St. Louis River | Unintentional | Fish parasite |
| Parasite | Ichthyocotylurus pileatus | 1995 | St. Louis River | Unintentional | Fish parasite |
| Parasite | Tryponasoma acerinae | 1986 | St. Louis River | Unintentional | Fish parasite |
| Parasite | Dactylogirus amphibothrium | 1986 | St. Louis River | Unintentional | Fish parasite |
| Parasite | Dactylogirus hemiamphibothrium | 1986 | St. Louis River | Unintentional | Fish parasite |
| Wetland, Aquatic Plants and Shoreland Woody Plants: (n=31, 36%) | |||||
| Barnyard Grass | Echinochloa crusgalli | <1972 | E. Lake Superior, MI | Intentional | Cultivation |
| Birdsfoot trefoil | Lotus corniculatus | 1975 | Kadunce Creek, MN | Unknown | Cultivation |
| Bitter dock | Rumex obtusifolius | <1985 | E. Lake Superior, MI | Unknown | Unknown |
| Bur reed | Sparganium glomeratum | 1936 | Superior Bay | Unknown | Unknown |
| Common mullein | Verbascum thapsus | ? | Unknown | Unknown | Unknown |
| Crack Willow | Salix fragilis | <1985 | E. Lake Superior, MI | Intentional | Cultivation |
| Creeping yellow cress | Rorippa sylvestris | <1985 | E. Lake Superior, MI | Unknown | Ballast (solid)? |
| Curlyleaf pondweed | Potamogeton crispus | 1988, 1996 | Knife River Marina, MN; Washburn Harbor, WI | Unitentional | With Fish or Recreational Boats |
| Eurasian watermilfoil | Myriophyllum spicatum | 1996 | Chequamegon Bay, WI | Unintentional | Aquaria or Recreational Boats |
| Field sow thistle | Sonchus arvensis | <1996 | E. Lake Superior, MI | Unintentional | Cultivation |
| Flowering rush | Butomus umbellatus | Unknown | Unknown | Unknown | Cultivation |
| Giant chickweed | Stellaria aquatica | <1985 | E. Lake Superior, MI | Unknown | Unknown |
| Glossy buckthorn | Rhamnus frangula | <1985 | E. Lake Superior, MI | Intentional | Cultivation |
| Hairy willow herb | Epilobium hirstutum | <1998 | Knife River mouth, Knife River, MN | Unintentional | Cultivation |
| Hairy willow herb | Epilobium parviflorum | <1998 | Knife River mouth, Knife River, MN | Unknown | Unknown |
| Hawkweed | Hieracium scabriscullum | <1996 | Sugar Loaf, MN | Unknown | Cultivation |
| Hawkweed | Hieracium scabrum | <1996 | Sugar Loaf, MN | Unknown | Unknown |
| Indian balsam | Impatiens glandulifera | 1984, 1998 | Grand Marais, MN, Lake Superior, ON | Unknown | Cultivation |
| King-devil | Hieracium piloselloides | <1996 | Sugar Loaf, MN | Unknown | Cultivation |
| Lady’s thumb | Polygonum caespitosum | <1985 | E. Lake Superior, MI | Unknown | Unknown |
| Lupine | Lupinus polyphyllus | 1982 | Beaver Bay, MN | Intentional | Cultivation |
| Marsh thistle | Cirsium palustre | <1990 | E. Lake Superior, MI | Unknown | Unknown |
| Narrow-leaved cattail | Typha angustifolia | <1972 | E. Lake Superior, MI | Unknown | Canals or Cultivation |
| Oak-leaved goose foot | Chenopodium glaucum | <1985 | E. Lake Superior, MI | Unknown | Railroads or Highways |
| Orange hawkweed | Hieracium scabriscullum, Hieracium scabrum | <1996 | Sugar Loaf, MN | Unknown | Cultivation |
| Poison hemlock | Conium maculatum | <1985 | E. Lake Superior, MI | Unknown | Cultivation |
| Purple loosestrife | Lythrum salicaria | 1907 | Duluth, MN | Intentional | Cultivation |
| Redtop | Agrostis gigantean | <1972 | E. Lake Superior, MI | Intentional | Cultivation |
| Spotted knapweed | Centaurea maculosa (biebersteinii) | <1989 | Sugar Loaf, MN | Unknown | Unknown |
| True forget-me-not | Myosotis scorpioides | <1989 | Widespread | Intentional | Cultivation |
| Water cress | Rorippa nasturtium aquaticum | <1985 | E. Lake Superior, MI | Intentional | Cultivation |
| Yard dock | Rumex longifolius | 1901 | Isle Royale, MI | Unknown | Cultivation |




