An Adaptive Management for Hawksbill Turtles

1. An Adaptive Management for Hawksbill Turtles Shin-ichi EBINA & Hiroyuki MATSUDA （Ocean Research Institute, Univ.Of Tokyo） • Thank to Grahame Webb (Australia) and Mari Kobayashi (Japan), Elvira Carrillo (Cuba)

2. 新プロ　DOBIS　変動班 管理と保全の変動モデル • 松田裕之・立川賢一・蝦名晋一・森光代（海洋研・資源解析） • 今年の研究：不確実な情報しかない「希少」海産生物の管理手法 • クロミンククジラの資源量推定に及ぼす観察員経験年数の効果（ＩＷＣロンドン） • キューバのタイマイの順応的管理によるリスク評価（SeaStar2000タイシンポ）

3. 399/yr 4744/yr Cuba CITES Proposal (2000) Hawksbill Turtles Harvest in Cuba Is 90% catch reduction enough for conservation?

4. CITES Proposals by Cuba • Down-listing from Appendix I to II, and permit export Hawksbill Turtles Products once to Japan

5. Controversy on CITES criteria • CITES Fauna & Flora Chairs: not be included in Appendix I when the risk of the listing … outweigh the conservation benefit of the listing, • IUCN: Listing of Endangered species in Appendix I is always benefit for conservation. See http://cod.ori.u-tokyo.ac.jp/~matsuda/2001/whale.html

6. http://news.bbc.co.uk/hi/english/sci/tech/newsid_1458000/1458234.stmhttp://news.bbc.co.uk/hi/english/sci/tech/newsid_1458000/1458234.stm

7. Problems of Hawksbill Turtle • Mixture of other endangered stock • (haplotypes of Cuban HT is different from that of other Caribbean HT, Koike’s group) • Bycatch ca700 juveniles and adults • Large uncertainty in life history, absolute population size, and age identification. • We need adaptive management

8. assess problems Adjust design implement Evaluate monitoring What is Adaptive Management?see also http://www.for.gov.bc.ca/hfp/amhome/AMDEFS.HTM • To control management policy adjusted to monitoring data (adaptability), • To include new knowledge flexibly (accountability), • To make consensus by various stakeholders, • To write falsifiable objects.

9. RMP in Whales(Revised Management Procedure) • To monitor stock size by research vessels • Pt+1 = Pt - Ct+1.4μPt[1 - (Pt/P0)2] • To decide catch limit Lt (> Ct) by Lt = 3μ(Pobs,t/P0 - 0.54)Pobs,t • Pobs,t = bPt [1+N(0,s)]

10. Feedback Management for sika deer in Hokkaido, Japan • To avoid overabundance and extinction risk, • To seek sustainable deer hunting, • To monitor population size • To catch females when %P>25%, males when 5%<%P<25% http://www.hokkaido-ies.go.jp/HIESintro/Natural/ShizenHP2/SIKA/DTdeerHP.htm

11. The age of overabundance will finish! Female hunting 95% CI Management Program started in 1998 1993

12. Merits of Adaptive Management • To clarify goals and objects, • To monitor population trends, • To changecatch with recent stock estimates, • Riskassessment based on a population dynamic model with uncertainties, • To test interim assumptions and models and to encourage further research.

13. Proposal of Goal and Objects for HT management • Sustainable use and population conservationunder uncertain scenarios, • Increase of catch quota if estimated female adults are more than …, • No catch if nested female adults (>50cm SCL) are fewer than 500, • Regulation of by-catch if …

14. Data about Hawksbills in Cuba ■growth rate and maturing rate at each size-class (from Ohtaishi(unpublished), Moncada et al.(1999) and Pilcher et al.(1999)) traditional harvesting by-catch:A by-catch:B

15. Population Dynamic Model(Determinate Growth)

16. Life History Parameters for Hawksbills in Cuba Mortality Rate ○After 1 year of age：0.1 ●Harvesting rate：depending on catch data ○Hatchling to 1-year-old：99.0% (Webb et al., in comm.) Fertility ●hatchling rate：0.69 (Moncada et al.,1999) ●proportion sex ratio：0.768 (Carrillo et al.,1999) ●nesting interval：2.42(yr) (Hoyle and Richardson,1993 etc.) ●clutches/season：2.0 (Moncada et al.,1999)

17. Simulation • Initial population size is 50,000-110,000 • Including uncertainty to each parameter • Assume facing bad environment every ten years on average • Changing annual survival rates • Hatchling rate：0.69 to 0.6 • Hatchling to 1-year-old：0.01 to less than 0.01 • We repeated calculation 300? times

18. Simulations under constant 500 catch 300 number of females (thousands) 200 100 year 2000 2020 2040 2060 2080 2100

19. Simulations under adaptive management number of females (thousands) 300 200 100 year 2000 2020 2040 2060 2080 2100

20. Risk of exploitation bans under the adaptive management • >?% with the next 1 century • No extinction over 300 simulated runs • Under the pessimistic assumptions

21. Summary • Adaptive management is robust, • Monitoring is indispensable • To examine detail biological data • To get the trend of population size • Consistent method and effort! Or • Record survey efforts and methods!

22. 来年度の課題 • 個体群管理から生態系管理へ • 勝川俊雄・木村紀雄 • Ecosimで得た時系列と順応的管理 • Ecosimの改良（群集・進化生態学の知見） • 特に、vulnerabilityとMixed Trophic Impact • 水圏群集生態学の新たな展開 • 松田裕之・中嶋美冬 • 魚の左右性の群集動態と進化機構の解明

23. What Remains To Be Done • Confronting model to the data we have already gotten from literatures • Running some simulation under some other scenarios • slower/faster-growing assumptions • fewer/-more initial population size • more rapidly/slowly maturing assumptions

24. Thank you!! • Welcome to ORI! • Especially for those who like to apply adaptive management to stocks in your country.

25. Does Sustainability Require No-catch? (IWC/SC London 2001) • Even under constant 150 annual catch, Southern Hemisphere minke whale might go extinct within the next 1000 years. • If 0 catch at lower stock level than 10,000 whales, the mean extinction time is far too long (1045 years) • Extinction risk assessment is still important for conservation.