Presentation is loading. Please wait.

Presentation is loading. Please wait.

New Tools for Management of Data-Poor Stocks Rainer Froese, GEOMAR, Kiel, Germany Pew Fellows Meeting, Gamboa, Panama, 9.12.2012 Workshop on Options for.

Similar presentations


Presentation on theme: "New Tools for Management of Data-Poor Stocks Rainer Froese, GEOMAR, Kiel, Germany Pew Fellows Meeting, Gamboa, Panama, 9.12.2012 Workshop on Options for."— Presentation transcript:

1 New Tools for Management of Data-Poor Stocks Rainer Froese, GEOMAR, Kiel, Germany Pew Fellows Meeting, Gamboa, Panama, 9.12.2012 Workshop on Options for the Management of Data-poor Stocks

2

3

4

5

6

7

8

9

10

11

12 Of all the possible r-k pairs in the rectangle, only the displayed ones did not collapse the stock or overshoot carrying capacity.

13 All r-k pairs under the bold line result in the same value of MSY. The outer lines contain 95% of the possible MSY estimates.

14 Reported catches with overlaid MSY estimate and 95% confidence limits.

15

16 From MSY to Management If MSY and mean catch over several years are known, then equilibrium biomass can be obtained from a Schaefer model: B/Bmsy = f(Catch/MSY)

17 Catch of 37 ICES stocks in 2010 after 6 years of MSY management, relative to actual catches

18 Biomass of 37 ICES stocks in 2010 after 6 years of MSY management, relative to actual biomass

19

20

21 Length Frequency Analysis North Sea flounder, 2000 - 2012

22 Length Frequency Analysis North Sea flounder, 2000 - 2012

23

24 Length Frequency Analysis Absolute slope = total mortality (Z). If Z is larger than r, then fishing mortality F exceeds natural mortality M.

25 References Martell, S. and R. Froese, 2012. A simple method for estimating MSY from catch and resilience. Fish and Fisheries, doi:10.1111/j.1467-2979.2012.00485.x R-code ICES_Data RAM_Data PDFR-codeICES_Data RAM_DataPDF Froese, R. and A. Sampang. 2012. Proxies for estimation of relative fishing mortality when biomass is unknown. ICES CM 2012/G:15, 1-17 DOC XLS Stocks Flounder MustelusDOCXLSStocksFlounderMustelus Froese, R. 2012. Putting the Catch-MSY method to a test: preliminary insights. Report from the WKLIFE workshop, 13-17 February 2012, IPIMAR, Lisbon, Portugal. DOCDOC Froese, R., A. Stern-Pirlot, H. Winker and D. Gascuel. 2008. Size Matters: How single-species management can contribute to ecosystem-based fisheries management. Fisheries Research 92:231-241, PDFPDF

26 Summary Catch-MSY method has been applied now to many stocks and seems to work satisfactorily MSY-only management worked well in most ICES stocks Additional information on stock development (e.g. from length frequencies) is important to check assumptions and confirm trends


Download ppt "New Tools for Management of Data-Poor Stocks Rainer Froese, GEOMAR, Kiel, Germany Pew Fellows Meeting, Gamboa, Panama, 9.12.2012 Workshop on Options for."

Similar presentations


Ads by Google