Biodiversity of Fishes on the Boreal Shield in Ontario

1. Biodiversity of Fishes on the Boreal Shield in Ontario Class 10 Presentation 1

2. Thanks to Nicholas E. MandrakResearch Scientist Great Lakes Laboratory forFisheries and Aquatic SciencesDepartment of Fisheries and OceansBurlington, ON

3. Outline • Defines some of the biological diversity of fresh water fishes in Ontario • What are the threats to fish biodiversity?

4. Biodiversity Includes • Species • Subspecies • Populations / Evolutionary SignificantUnits (ESUs) • Morphotypes • Assemblages / Communities

5. Species What is Biodiversity? • 128 native, 19 introduced fish species in Ontario. • Of the 128 species in 24 families, 5 were endemic to the Great Lakes • No species endemic solely to Ontario. • Greatest fish species richness south of the Shield.

6. What is Biodiversity?

7. Great Lakes Ciscoes What is Biodiversity?

8. Freshwater Fish Richness What is Biodiversity?

9. Species What is Biodiversity? • Greatest fish species richness south of the Shield. Why? • Combination of what happened following the last Ice Age, current climate and water chemistry.

10. evolutionary processes North America ~600 spp. postglacial dispersal, climate, water chemistry Northern North America ~130 spp. morphometry, water chemistry Shield ~60 spp. biotic interactions Shield Lakes <30 spp. modified from Tonn 1990

11. Postglacial Dispersal What is Biodiversity?

12. Postglacial Dispersal Some genes from fish that survived in Beringia refugia What is Biodiversity? Mandrak and Crossman 1992

13. Mean Annual Air Temperature What is Biodiversity?

14. Productivity What is Biodiversity?

15. Species What is Biodiversity? • Few species found in northern Ontario that are not found in south. • Few exceptions

16. What is Biodiversity?

17. What is Biodiversity?

18. What is Biodiversity? 1 cm

19. What is Biodiversity?

20. What is Biodiversity?

21. Subspecies What is Biodiversity? • No longer used by ichthyologists. • None listed in official names list by American Fisheries Society.

22. Populations / ESUs What is Biodiversity? • Population - group of individuals of single species inhabiting specific area, limited gene flow with other populations. • Many populations restricted to single lakes (e.g. headwater lakes). • Evolutionary Significant Units (ESU) – population, or group of populations, that is substantially reproductively isolated and represents an important component in the evolutionary legacy of the species. • Populations/ESUs of only a few species in Ontario identified, none comprehensively.

23. Distributions of mtDNAlineages among lake trout populations Wilson and Hubert (1996)

24. Morphotypes What is Biodiversity? • Individuals of a species may exhibit variation in physical characteristics = phenotypic variation. • May be result of: • adaptation to: • different habitats (e.g. sunfishes) • different prey to minimize competition (e.g. ciscoes developing different gill rakers depending on food source) • predation (e.g. sticklebacks with different plates on their backs) • genetic drift caused by: • isolation (founder effect) (e.g. Aurora trout isolated in 5 lakes) • limited gene flow (e.g. lake trout, little migration)

25. Algonquin Ciscoes What is Biodiversity?

26. Aurora trout What is Biodiversity? Aurora trout Brook trout

27. Communities What is Biodiversity? • Communities – group of interacting species living in a specific area, or all species living in a given area. • Assemblages – limited to specific taxon (e.g. fishes) • Fish assemblages on Shield • simpler than south of Shield • fewer warmwater predators (e.g. basses)

28. What are the threats to fish biodiversity? • Habitat alteration, loss • Overexploitation • Introduced species • Atmospheric pollution

29. 1. Habitat alteration and loss Threats to Biodiversity • Habitat is the physical, chemical and biological components in a species’ environment required for survival.

30. 1. Habitat alteration and loss Threats to Biodiversity • In southern Ontario, agriculture and urbanization e.g. habitat loss, runoff effects physical (turbidity) and chemical (nutrients) quality of water. • In northern Ontario, direct and indirect effects of resource extraction. e.g. logging directly affects water supply, physical (turbidity) and chemical (nutrients) quality of water; logging roads have perched culverts, increased access leads to spread of overexploitation, introduced species. e.g. mining tailings directly pollute water, smelting can lead to acid precipitation.

31. 1. Habitat alteration and loss Threats to Biodiversity Perched culverts Turbidity Mine tailings

32. 2. Overexploitation Threats to Biodiversity • Overfishing exceeds natural mortality of population, or targets spawning stock (typically larger individuals). • Commercial fishing in larger lakes. • Recreational fishing in smaller lakes.

33. 1930s saw demise of commercial catch in L Huron due to over fishing. Sea lamprey may have had an effct as well 2. Overexploitation Threats to Biodiversity 1950s saw demise of ciscoes due to over fishing. Ciscoes not affected by lamprey

34. Great Lakes Ciscoes Threats to Biodiversity Extirpated in GL Extinct Extirpated in GL* Extinct Extirpated in GL* * Except Superior

35. 3. Introduced Species Threats to Biodiversity • Species not native to an ecosystem, introduced deliberately or accidentally. • Deliberately through: • authorized stocking (outdated process) • illegally to establish “glory hole” for sport or bait fishes (seeding lakes) • releasing unused bait or unwanted aquarium fishes. • Accidentally by ballast water, bait bucket water, boats, movement through canals.

36. Smallmouth Bass Introduced Source: Checklist of Ontario Freshwater Fishes Annotated with Distribution Maps (Mandrak and Crossman 1992)

37. Threats to Biodiversity

39. Threats to Biodiversity May have been in L Ontario spread to upper Gt Lakes after Welland Canal built

40. 3. Introduced Species Threats to Biodiversity Potential impacts on native species: • Habitat alteration or destruction (e.g. carp uproot aquatic plants) • Competition with, predation on, native species. (e.g. lamprey, ruffe) • Introduction of diseases and parasites (e.g. whirling disease in trout)

41. Threats to Biodiversity

42. Threats to Biodiversity • ruffe

43. Threats to Biodiversity Using C13/12 ratio gives us idea of trophic position of fish. Higher ratio higher trophic position Vanden Zanden et al. 1999

44. Atmospheric Pollution Threats to Biodiversity • Anthropogenic contributions to atmosphere can have far-reaching (e.g. global) effects on aquatic environments. • Acid precipitation, climate change.

45. Acid Precipitation Threats to Biodiversity • Direct effects: loss of fish populations • Numerous indirect effects.

46. Change in Mean Annual Temperature 1990-2050 Threats to Biodiversity +2°C to 5°C

47. Change in Mean Annual Temperature 1990-2080 Threats to Biodiversity +5°C to 8°C

48. Climate Change Threats to Biodiversity Potential Effects • Colonization of Shield by warmwater introduced species and associated impacts (N.B. requires human assistance). • Negative impacts on cool- and cold- water fishes resulting local and regional decline in condition, abundance and range.

49. Conclusions • Biodiversity at sub-specific levels largely unknown. • Threats: habitat degradation/loss; overexploitation; introduced species; atmospheric pollution. • Synergistic interaction of threats likely to be exacerbated by climate change.

50. Conclusions • Science Needs • Identify biodiversity at sub-specific levels. • Identify limiting factors and threats. • Identify mitigation and adaptation strategies. • Protection and Recovery Needs • Identify gaps in protection . • Identify and undertake recovery activities.