1. The Effect of Fishing on Species and Genetic Diversity

2. Genetic resources are an important element of conservation –Species –Within Species

3. I. The Loss of Species Is this a problem in the sea? How do we know?

4. Latimeria chalumnae (coelacanth) c. 1938

5. Documented Extinction Steller’s Sea Cow Caribbean Monk Seal Eelgrass Limpet Rocky Shore Limpet Asian Periwinkle Horn Snail New Zealand Grayling Sea Mink Great Auk Vanvoorstia bennettiana (Australian red alga)

6. Sea Turtles, Sharks, Rays...

7. The Role of Fishing in Extinction Events

9. II. Loss of Populations

10. Pacific Salmonids Population rich –106 populations extirpated in US –142 populations extirpated in Canada –In the last 30 yrs over 40% of range lost

13. 4VsW September/October 1996 longline survey catches 46 43 6357

14. Marine fish have much more genetic structure than previously supposed

15. Maintenance of Genetic Diversity Organization of populations in time and space Ratio of within and among population variation

16. Events Prior to Extinction Extirpation –Range contraction –Fragmentation

17. Adriatic Sea stock of Beluga Sturgeon Atlantic Ocean population of Gray Whale Gulf of St. Lawrence walrus –populations of 82 species of marine fish in North America believed to be at risk

18. Brosme brosme (cusk) Abundance 1970-2000

19. Loss of Populations = Loss of Genetic Diversity

21. A significant amount of genetic diversity could be attributed to spatial structure No variance component could be attributed to temporal changes Ruzzante, Taggart et al. In Press. Stability in the historical pattern of genetic structure of Newfoundland cod (Gadus morhua) despite the catastrophic decline in population size from 1964 to 1994. Conservation Genetics

22. III. Loss of within population genetic diversity

24. Selective Fishing

27. By removing the large fish selectively over time the remaining fish are slow-growing and early-maturing Genetic or Ecological? –temperature –abundance of prey –degree of competition

28. Traits affected by fishing? Weight-at-age Length-at-age Age-at-maturity Length-at-maturity Spawning season Number and size of eggs

29. Selective fishing can cause heritable differences in life-history traits that control sustainable yield

30. Problems and Solutions Species extinction Genetic complexity Selective fishing Address at the population level Manage spawning components Reduce fishing intensity Structure effort Reduce selectivity Reduce fishing intensity

31. Numbers are not enough