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** Sustainable Harvest Rule for Recovery of the Jack Mackerel Population**

Explore the importance of rebuilding the Jack Mackerel population through sustainable harvesting practices and biological reference points. Discuss strategies for population recovery and the role of biomass escapement levels. References to key studies and implications for fishery management are highlighted.

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** Sustainable Harvest Rule for Recovery of the Jack Mackerel Population**

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  1. Anexample of harvest rule control forrecoverythejackmackerelpopulation Cristian Canales- IFOP- Chile

  2. Mainquestions • Whatwewantto do withjackmackerel (JM) population? • Whatisthe status of JM population? • Why and howrebuildthe JM population?

  3. Whatwewantto do with JM population? • Wesupposethere’sanimplicitdesire, thatistheconservation. Whatdoesconservation mean? • Thesustainableexploitation: allcountrieswantto be at thebussinessforlong time. • Ideally, wewanttogetthemaximumyield and maintainitover time (MSY). Howthereachit?

  4. “Believeornotbelieve in MSY” • Why in fishery management is considered a biomass escapement level?. • When we accept the existence of S-R relationship (no parents -> no recruits), we are accepting the existence of MSY implicitly.

  5. Whatisthe status of JM population? • A general target of many fishery resources is to maintain the population and its fishery around MSY (Bmsy and Fmsy). • In this sense, the pair (Bmsy; Fmsy) defines the Biological Reference Points - BRP (or any quantity close to these). When we cannot estimate the MSY variables properly, we can adopt a proxy (~40%Bo) • We have talked about about this. See Canales C.(SWG-11-JM-01, 2012), Canales & Hintzen (SWG-11-JM-09, 2012)

  6. MSY

  7. Whatisthe status of JM population? (Cooper, 2006)

  8. Estimatingthe MSY in JM

  9. Recruitments

  10. Whatisthe status of JM population?

  11. Twowaystorecoverythepopulation Constantfishingmortality(F=Fmsy), HereFmsyisappliedindependently of population status 2) Rampstrategy(F = Fmsy * SSB/SSBo), Here the Fmsy is reduced as a proportion of population depletion when the overfished have been declared

  12. The target isreachedafter 8 years It is necessary more than 10 yrs to reach the target

  13. Ramp strategy: The cost are lower catches at the beginning , but in the future, landings will be larger.

  14. If the recruitment doesn’t back to historical level, the MSY won’t be reached never. If a regime shift is going on, the BRP should be re-evaluated

  15. Remarks 1. To recovery the population, it is necessary to declare the condition as overfished 2. To declare the overfished condition, it is necessary define BRP (target and/or limit) 3. The population recovery may be reached, considering the variables related to MSY (or proxy) as biological reference points (BRP) 4. Considering the uncertainty of the future recruitments, a harvest rule control should be defined in order to sure the population’s rebuild.

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