Biogeography, Conservation, and Genetics Biology of Fishes 11.13.12

1. Biogeography, Conservation, and GeneticsBiology of Fishes11.13.12

2. Overview Exam 2 information Final Exam information Presentations Biogeography, Conservation, and Genetics

3. Presentation Guidelines Guidelines online All groups submit written reports 11.27.2012 Attendance required at all student presentations Student Presentations material will be on Final Exam

4. Syllabus Revisions November 15 – Conservation ecology case study synthesis November 20 – Exam 2 November 22 – Thanksgiving Break November 27 – Student Presentations November 29 – Guest Lecture 3 December 4, 6, 11 – Student Presentations December 19 – FINAL EXAM (Cumulative) 10:30am-12:30pm

5. Biogeography • Biogeography– the study of the distribution of life on Earth, or which organisms live where and why • 2 primary components • Historical biogeography – influences on distribution over long temporal and large spatial scales • Ecological biogeography – influences on distribution based on interactions with environment over short temporal and small spatial scales • Foundation in continental drift and plate tectonics • Freshwater fishes provide some of the most important data

6. Biogeography • Historical Biogeography– why is a taxon restricted to a particular geographic area? • 2 primary components/processes (consider together) • Vicariance – barrier appears and separates ancestral population into two groups, eventually separate taxa (barrier & taxa same age) • Dispersal – taxa develop from dispersal into new areas from ancestors that originally occurred elsewhere. Previously existing barrier is crossed by some individuals, eventually separate taxa (barrier older than taxa)

7. Biogeography • Historical Biogeography– why is a taxon restricted to a particular geographic area? • Vicariance • Dispersal

8. Biogeography 2 primary methods Phylogeography– distribution of geneologies (gene lineages) within and among closely related species Cladistic biogeography– based on cladistics (phylogenetics) to imply relationships which reflect geological and ecological history (area relationships inform general patterns among taxa) Process (mechanisms) versus Pattern (distribution)

9. Biogeography • Biogeography of Fishes • ~29,000 species • ~60% marine, ~40% principally freshwater • Less than 1% are migratory between fresh & saltwater • Over 10,000 of 29,000 species occur in freshwater (0.01% of world’s water) • Marine environments not well-explored (deep-sea, second coelacanth)

10. Biogeography • Biogeography of Fishes • Freshwater Regions (Hart & Reynolds 2000) • Nearctic (North America) 1060 • Neotropical (South & Central America) 8000 • Palaearctic (Europe, excluding former USSR) 360 • Ethiopian (Africa) 2850 • Oriental (Southeast Asia) 3000 • Australian (Australia & New Guinea) 500

11. Biogeography Biogeography of Fishes

12. Biogeography • Biogeography of Fishes • Marine Regions (Hart & Reynolds 2000; shore to 200 m) • Western North Atlantic 1200 • Mediterranean 400 • Tropical western Atlantic 1500 • Eastern North Pacific 600 • Tropical eastern Pacific 750 • Tropical Indo-West Pacific 4000 • Temperate Indo-Pacific 2100 • Antarctica 200

13. Biogeography • Biogeography of Freshwater Fishes • Most freshwater fauna are poorly known (exceptions are North America and Europe) • Thorough survey work needed to inform historical biogeography; too late in most cases • Endemic fauna wiped out • Overexploitation, invasive species, habitat alteration • Focus on North American freshwater species • Mississippi River refugium and Wisconsinan Glaciation • Glaciated versus non-glaciated regions

14. Biogeography • Focus on North American freshwater species • Mississippi River refugium and Wisconsinan Glaciation

15. Biogeography • Focus on North American freshwater species • Glaciated versus non-glaciated regions

16. Conservation • Biodiversity loss • Global crisis • Threatens all major habitats • Multiple geographical and ecological scales • Loss of local populations can have cascading effects • Disrupt ecosystem services • Relationship between biodiversity and ecosystem services is a function of local populations, not just existence of the species – conservation of populations is important

17. Conservation • Freshwater systems experience dramatic declines in biodiversity • Greater biodiversity loss than most terrestrial systems • Freshwater conservation priorities lag • Considered “sumps” and “receivers” of industrial & domestic wastes and land-use effluents • Exceptionally vulnerable to anthropogenic influence

18. Conservation • Freshwater systems experience dramatic declines in biodiversity • ~3,600 of 10,250 known freshwater species (35%) are considered imperiled or threatened • ~95-170 already extinct • Primary reasons are habitat alteration and exotic species invasions • 95% of extinctions have occurred in past 50 years

19. Conservation Genetics Identification of “stock” or population structure is a primary goal in genetics of fish populations Multiple techniques – nuclear DNA, mitochondrial, microsatellites Applications to fisheries management and conservation Once lost, cannot be restored

20. Conservation Genetics • Multiple techniques (using PCR) • Nuclear DNA – evolves slowest, conservative; good for species studies • Mitochondrial DNA – evolves faster, maternally inherited; good intermediate for species and population studies • Microsatellites – repeating structures in nDNA; evolves fastest, high degree of population resolution

21. Conservation Genetics Conservation of genetic diversity is important for biodiversity and ecosystem function Once lost, diversity cannot be restored Poor knowledge of diversity partitioning within species or among populations – without appropriate knowledge, cannot assess conservation measures

22. Conservation Genetics Quantification of genetic population structuring is needed, particularly for threatened or vulnerable species Structuring much more extensive for freshwater & anadromous species compared to marine species (endemics, salmonid stocks)

23. Conservation Genetics Prioritize stocks based on genetic and ecological consequences of extinction Conservation efforts include habitat protection, reduction of harvest, stock enhancement (using same strain), translocation* Determine minimum effective population size High population size and diversity allows for some adaptive evolution and can reduce effects of inbreeding

24. Conservation Genetics Identification of “stock” or population structure is a primary goal in genetics of fish populations Multiple techniques – nuclear DNA, mitochondrial, microsatellites Applications to fisheries management and conservation Once lost, cannot be restored

25. Conservation Genetics Important for management and conservation of both commercial and non-commercial species Should be used in conjunction with other techniques – life history traits, morphological characteristics, microchemistry – for more complete picture of structuring Careful husbandry of genetic resources is required (catalog, monitor, conserve)