1. Life-History Traits of Fishes: A Review with Application for Mangement of Data-Poor Stocks Rainer Froese GEOMAR, Kiel, rfroese@geomar.derfroese@geomar.de XIV European Congress of Ichthyology 04 July 2012, Liège, Belgium

2. Overview Status of global fish stocks Rio+20 and the CFP Reform Principles of ecosystem-based fisheries management Growth and Mortality New method for MSY Conclusions

3. ‚Stability‘ in world catches masks decline of fish stocks 3

4. Global Catches are Stagnating Pauly and Froese, 2012

5. Global Effort Keeps Increasing Pauly and Froese, 2012

6. Global Fish Stocks are Shrinking If catches are stagnating while effort is increasing then fish stocks must be shrinking Pauly and Froese, 2012

7. The method to assess all global stocks proposed by Froese & Kesner-Reyes (2002), subsequently used by others, including Worm et al. (2006) for their 2048 prediction, is sound Global overfishing continues FAO, by using a subset of well-researched stocks, severely underestimates global overfishing 7

8. Status of Global Fish Stocks 2009 8 Neue Bestände Zusammengebrochen Undeveloped Developing Fully exploited Overexploited Collapsed Froese et al. Marine Biology 2012

9. 9

10. European Stocks and Fisheries 10

11. Status of all European Stocks 11 Neue Bestände Zusammengebrochen Developing Fully exploited Undeveloped Overexploited Collapsed Froese et al. Marine Biology 2012

12. Status of European Fish Stocks 12 Landings from ICES 2010, MSY from Froese and Proelß 2010

13. Politics

14. News from Rio +20 Article 168 of the The Future We Want: Outcome of the Conference deals with fisheries: Governments commit to intensify efforts to restore stocks at least to MSY levels They commit to urgent measures, „including by reducing or suspending fishing...“ They commit to ecosystem-based fisheries management

15. News from the CFP Reform The Commission (Maria Damanaki) has presented a reasonable CFP reform proposal (although less than Rio +20) The Council of Agriculture Ministers has recently decided upon its ‚compromise‘ position The European Parlament will present its position in October, then a new compromise has to be negotiated 15

16. The Council Compromise Postpones sustainable fishing for stocks without F msy estimates until 2020 Proposes an administrative monster for reduction of discards until 2020 Introduces lots of loopholes for continued overfishing, e.g. of not „significant“ species in mixed fisheries 16

17. The General Problem Over 4,000 species of fishes are harvested from the wild globally (FishBase 02/2012) Full stock assessments are available for only a few hundred species

18. The Solution General principles combined with incomplete knowledge are sufficient for reasonable management (Lessons learned after 30+ years of managing the Great Barrier Reef, Josh Gibson, pers. comm., 21.6.2012)

19. The Fisheries Question How much can we safely take from a fish population? How much mortality can we add without destroying the stock?

20. The Answer Principles of Ecosystem-based Fisheries Management Never take more than all other predators combined To avoid collapse with high certainty, take less – For regular fish, take ¾ of natural mortality – For forage fish, take ½ of natural mortality Pikitch et al. 2012

21. How to Estimate Natural Mortality? From decrease of numbers by age class (only about 200 studies in FishBase; Z = F +M) From growth parameters From longevity From maximum size

22. Most Species Grow Forever (Exception: birds and mammals) W t =W ∞ (1-e -(K t) ) 3

23. Growth, Mortality and Reproduction Froese & Pauly, in press Reproductive output is maximized if M <= 1.5 K Maturation depends on parental care

24. Reproductive Strategies and Maturation A B C Froese & Pauly, in press; FishBase 04/2011

25. M = 1.5 K Plot of mortality M predicted from growth parameter K over observed mortality, for 294 growth and mortality studies of 192 species of fishes. Data from FishBase

26. How to Estimate Natural Mortality? From growth parameters: M = 1.5 K From longevity

27. Taylor‘s (1958) Maximum Age Taylor’s maximum age at 95% L ∞ = 3/K plotted over observed maximum age, based on 510 growth studies for 391 species of fishes. FishBase 02/2012

28. M = 4.5 / max. Age

29. How to Estimate Natural Mortality? From growth parameters: M = 1.5 K From longevity: M = 4.5 / t max From maximum size

30. If No Growth Studies are Available Scatterplot of von Bertalanffy growth parameters K over W ∞ from 4,021 growth studies of 1,020 species of iteroparous fishes. A robust regression (bold line) accounts for 48% of the variability in the data. FishBase 02/2012

31. Add More Knowledge Estimating K as a function of max weight, climate zone, resilience, and habitat explained 68% of the variability in the data.

32. How about Data-Poor Stocks? Knowing the fraction of the stock that can be fished is fine, but what about the many stocks for which no abundance is known? New method (Martell & Froese 2012) estimates the maximum sustainable yield from catch data and resilience

34. Excellent Agreement Plot of MSY estimated by the Catch-MSY method versus full stock assessments for 48 stocks from the Northeast Atlantic. The broken line indicates the 1:1 relation while the dotted lines indicate ratios of 0.5 and 1.5, respectively.

35. MSY-only Management (next study) If the stock size is above 50% of unfished level take 75% of MSY from ‚regular‘ fish stocks take 50% of MSY from forage fish If there is doubt about the stock size stop fishing resume fishing at 25% of MSY after signs of recovery increase fishing slowly to 50% or 75% of MSY

36. Conclusions Overfishing is ongoing and increasing globally International agreements for sustainable fishing are in place but need to be implemented Life-history traits can help with reasonable, simple management

37. Thank You Rainer Froese GEOMAR, Kiel, Germany rfroese@geomar.de P.S. Please send you results (growth, reproduction, maturity, fecundity, spawning, food items, diet,...) and photos to FishBase.