Status of Unintentionally Introduced Non-native Aquatic Species in Lake Superior, 2002

1. Status of Unintentionally Introduced Non-native Aquatic Species in Lake Superior, 2002 Mark P. Dryer & Gary Czypinski USFWS-Ashland Fishery Resources Office Douglas A. Jensen Minnesota Sea Grant Program

2. Cumulative Number of Non-native Species Introduced into the Great Lakes, 1993 (n=139) Data from Mills et al. 1993

3. Introduced Aquatic species in the Great Lakes Sorted by Taxonomic Group 60% 20% 18% Data from Mills et al. 1993

4. Fish Community Objectives for Lake Superior • Prevent the introduction of any non-indigenous aquatic nuisance species. • Prevent or delay the spread of non-indigenous aquatic nuisance species, where feasible. • Eliminate or reduce populations of non-indigenous nuisance species, where feasible. Source: Public Discussion draft, March 2001

5. Proportion of native and introduced fish species in the Great Lakes Based on Mills et al. 1993, D.A. Jensen (manuscript in prep 2000)

6. Lake Superior Non-native Species - 32 • 17 fish (53%) • 5 aquatic invertebrates (16%) • 4 diseases and parasites* (12%) • 6 aquatic plants (19%) 61% arrived since 1960 Jensen, D.A. Manuscript in Preparation 2000

7. Sources of non-native species in Lake Superior Sources of releases:* 10 ballast water 7 unintentional stocks 6 intentional stocks 5 canals and diversions 4 bait bucket/recreation boats 3 nursery/cultivar 1 biological supply house/aquarium release 1 unknown Total: 32 (8 intentional, 23 unintentional, 1 unknown) * total number >32 because of multiple pathways for several species

8. Ship ballast, hulls and hull sediments are the primary source of unintentionally introduced non-native species in Lake Superior

9. Ballast Water Management Progress • Great Lakes shipping industry voluntary guidelines. • Michigan enacted legislation. • Legislation under consideration in Wisconsin. • U.S. Coast Guard regulations for ocean vessels. • Great Lakes Panel on ANS, Policy Statement • Ballast management technology demonstrations.

10. Unintentionally Introduced Fish (9) in Lake Superior • Ruffe ship ballast • Fourspine stickleback ship ballast • Threespine stickleback ship ballast • Round goby ship ballast • Tubenose goby ship ballast • White perch ship ballast • American eel canals • Sea lamprey canals • Alewife canals/ballast

11. Ruffe (Gymnocephalus cernuus) • Lake Superior – west half • Lake Huron – at Alpena, MI

12. Threats and Impacts • Grows rapidly. • High reproductive output. • Aggressive feeding habits. • In St. Louis River, yellow perch, emerald shiner, and trout perch declined. • Yellow perch growth slower in competition w/ruffe.

13. (USFWS Ashland FRO, USGS Lake Superior Biological Station)

14. Ruffe density in 4 south shore tributaries to Lake Superior; 1995-2001 (USFWS Ashland FRO, USGS Lake Superior Biological Station)

15. Round goby (Neogobius melanostomus) Tubenose goby (Proterorhinus marmoratus) Round goby Tubenose goby

16. Threats and Impacts • Dominates spawning sites of other fish. • Spawns numerous times . • Tolerates low DO for several days. • Aggressive feeding habits. • Feeds on eggs of sculpin, darters, and logperch. • Displaces native bottom-dwelling fish.

17. Round goby Source: USGS Lake Superior Biological Station

18. Threespine stickleback (Gasterosteus aculeatus) • Marquette Harbor • Black Bay • MN, WI, MI tributary estuaries

19. Threats and Impacts • Impacts largely unknown, but may compete w/native sticklebacks. • Feed on zooplankton, oligochaetes and chironomids. • Inhabits shallow, sandy-bottomed shoreline habitats.

20. Fourspine stickleback (Apeltes quadracus) • Thunder Bay Harbor

21. White perch (Morone americana) • St. Louis R. estuary • Wisconsin tributary estuaries • Chequamegon Bay • Michigan tributary estuaries

22. Threats and Impacts • Eggs are an important diet component. • Yellow perch growth rates declined in some areas where co-exist. • Hybridize with native white bass in Lake Erie. • Known to overpopulate habitats of native fishes and become stunted.

23. Alewife (Alosa pseudoharengus) • Widespread but scarce

24. Threats and Impacts • A diet rich in alewifes may result in a thiamine deficiency in predators disrupting their reproduction. • Effective predators of lake trout fry. • Populations can explode without predation.

25. American eel (Anguilla rostrata) • St. Louis R. estuary • Nemadji R. • Black Bay

26. Unintentionally Introduced Invertebrates in Lake Superior (5) • Zebra mussel ship hull • Spiny waterflea ship ballast • Rusty crayfish multiple • Asiatic clam ship ballast • Aquatic oligochaete* ship ballast *widespread in other Great Lakes but not confirmed in Lake Superior.

27. Zebra mussel (Dreissena polymorpha) • Harbors and sheltered bays

28. Threats and Impacts • Clog intake pipes; foul ships, shores, docks and rocks. • Caused millions dollars in economic damage to industry and recreation. • Threaten native mussels.

29. Spiny waterflea (Bythotrephes cederstroemi=longimanus) • Throughout Lake Superior

30. Threats and Impacts • Rapid reproductive rate compete with young fish for food. • Nuisance to recreational and charter fishers.

31. Rusty crayfish (Orconectes rusticus) • St. Louis R. • Pidgeon R. • Thunder Bay • Inland lakes along U.S. shore

32. Threats and Impacts • More aggressive than native crayfish, out competing them for habitat. • Reduce aquatic plant abundance and diversity. • Less susceptible to predation than native crayfish.

33. Recommendation • Prevent the future introduction of any non-native species to Lake Superior.

34. To support recommendation(s) • Develop and support policy. • Implement management. • Conduct research, assessments and monitoring. • Conduct aggressive public education.

35. For Endangered Species,Extinction is Forever

36. For Invasive Species,Introduction is Forever

37. No Control is 100% Effective;There is NoSilverBullet!