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Management of Whaling 鯨類の資源管理 Hiroyuki Matsuda （松田裕之） Ocean Research Institute, U. of Tokyo（東大海洋研) IWC/SC Japan Delegate WWF Japan Adviser （自然保護専門委員） Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • AM is needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 捕鯨史=乱獲と禁漁の歴史 History of whaling = overexploitation & ban • 1946 Blue Whale Unit – (シロナガスクジラ換算制) • 1975 New Management Procedure – 不確実性への配慮がなく、非現実的 • 1992 Revised Management Procedure – 改定管理方式（RMP) agreed by IWC/SC – Revised Management Scheme not yet. Both overexploitation and non-use make no sustainable intake.乱獲も禁漁もだめ N r 1 f N dt K • fN: Catch • Sustainable if 0<f<r • Stock collapse if f>r • Maximum Sustainable Yield (MSY) if f = r/2 Production/Yield dN Kr/4 f r K/2 K Stock size 7 Do we know the exact MSY? Be conscious uncertainty. Requiem to MSYへの鎮魂歌 • Ecosystem is uncertain, nonequilibrium and complex • MSY ignores all the three. 不確実 Recovery probability of mackerel 資源回復確率 70-80年代の漁獲圧なら 90 年代の未成魚乱獲 を続けると 非定常 複雑性 Species replacement AM makes chaos. 捕 食 者 密 度 被食者密度 Constant Harvest Ratio is Dangerous. 漁獲率(努力)一定方策は危ない q • dN / dt = r [1 – (N / K) ] N – fN, • Maximize yield at fMSY = rq / (1 + q). • If estimates of r, K, q and f includes uncertainty, MSY is not achieved, nor extinction risk is not eliminated. • Any level of constant fishing effort does not eliminate the risk of stock collapse. Extinction risk & expected yield fMSY is neither sufficient nor necessary to stock conservation. FMSYは資源保全に不必要不十分 Low uncertainty in r High uncertainty in r Threat of biodiversity is serious if the population is below MVP • Minimum viable population (MVP) is defined as threat of demographic stochasticity (e.g., all mothers make sons = 50) and genetic degradation (=500). • The “50/500” law does not guarantee a zero-risk. • If population size > 10,000, the mean time to extinction is usually far too long (I ignore > 1 million yrs). 8 Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 Precautionary principle Rio Declaration 1992, Principle 15 • “In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing costeffective measures to prevent environmental degradation. 2 Should any few risk be avoided? (IWC/SC 2001 report, p.93) • Constant rate of exploitation of whales with environmental variability was still “equivalent to an unsustainable ‘mining’” (still positive risk) • Under the RMP, “the time scales were far too long (1045 years)” (>>the age of cosmos) • “the long time-scale was necessary to examine the mechanisms of the interaction between environmental variability and exploitation.” ???? 9 Can you imagine goods of larger number than I do?私より大きい数が言えますか? • • • • • 10 Human Population – 世界人口 – 10 10 Age of Cosmos – 宇宙年齢– 10 yrs 11 20 Astronomic scale – 星の数 – 10 -10 30 DNA combination – 生物進化 – 10 Anti-whalers risk threshold – 反捕鯨団 45 体が拒否するリスク – 10 yrs 1050 • Macroscale Tunnel Effects 10 ? Fallacy of Seeking Zero-Risk Ri s k f a c t or s Mor t a l i t y Ri s k f a c t or s Mot or c y c l i ng 2000 Rode o Al l f a c t or s 1000 Fi r e Kitoh’s anxiety (鬼憂) Smok i ng Ca nc e r f r om s mok i ng Mor t a l i t y 3 Qi’s anxiety 2.8 300 Tr i ha l ome t ha n e t c 0.8 (杞憂) 0.8 120 Pe a nut but t e r 3s poons /da y Fi r e f i g ht i ng 80 Be e f s t e a k 85g /da y Hung g l i de r 80 Fl ood Coa l mi ni ng 63 Fa r mwor k 36 Fa l l i ng s t a r s Aut omobi l e 24 0.5 0.06 St r uc k by l i g ht e ni ng 0.05 < 10 -5 A small falled leaf fire ? The number of died person per 100,000 per year 生 涯 リ ス ク は 上 記 の 数 字 が （ 松 田 注 :年 齢 ， 年 代 に よ り ） 大 き く 変 わ ら な い と す れ ば 約 7 0 倍 し た も の と な る ． Rodricks 22 Recipe for environmentfriendly life Keep Accountability and Adaptability Justify by ourselves, not by USA Live in a Rabbit Hatch, Do not Use more Energy than 20 Elephants! Use Any Parts of Bioresource. Do not Cull, but Eat Bioresource. Human First, Nature Second. Fallacy of applying PA to MSY 予防措置自身がMSY不達成のリスク要因 • If we adopt biased (precautionary) estimates, expected yield is again negatively biased. • MSY should be based on unbiased, most likely estimates (Error in quota is reversible if adaptive management is adopted) • MVP should be based on biased estimates, or PP. (Lost of biodiversity is irreversible) • MSY is usually >>MVP, but is <MVP in some local population. 10 Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 Is sustainable use compatible with uncertain world? 持続的利用と不確実性は両立できるか? If we adopt Adaptive Management. 順応的管理とは What is Adaptive Management? • Adaptability（順応性） – 状況を見て政策を変える – その変え方を決めておく • Accountability（説明責任） – 未実証の前提でリスク評価 – 新たな知見を取り込み、過ちを改める • Falsifiability（反証可能性） – どんな事態を招いたら失敗か事前に明記 順応学習とフィードバック制御 Adaptive Learning & Feedback Control Data Fish Stock Dynamics with Fishery Dynamics Model State Variable Decision Making of Fisheries Management 勝川俊雄T.Katsukawa：博士論文(2002)より A Risk Management for sika deer H Matsuda, K Kaji, H Uno, H Hirakawa & T Saito (Official English web site by Hokkaido Government: http://www.hokkaido-ies.go.jp/HIESintro/ Natural/ ShizenHP2/SIKA/deerEng/ History of deer in Hokkaido Island = Overexploitation, hunting bans and overabundance 1,000,000 Catch 100,000 10,000 1,000 100 10 1875 1895 1915 1935 1955 1975 1994 Damage on forests by deer http://www.marimo.or.jp/Kushiro_shichou/ezosika/cover.html http://www.hokkaido-ies.go.jp/HIESintro/Natural/ShizenHP2/SIKA/DTdeerHP.htm Density-dependent hunting pressure %P>50% 25% < %P 5% < %P %P <5% or after the severe winter Emergency culling Gradual population reductions (catch females) Gradual population increases (catch males) Hunting bans Population began to decrease. Female hunting Management Program started in 1998 95% CI 1993 Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 改定管理方式は順応的管理の先取りだっ た。RMP is an AM 2 MSY limit stock level 1 managed resource Unused resource Catch quota Fishing rate Protected resource 0 0 0.2 0.4 Production 0.6 Relative Stock Size P t /P 0 0.8 1 MSY at 60%, 0 catch at 54% Underestimation of Uncertainty 資源量推定誤差の過少推定 400 350 300 250 200 150 100 50 0 1st Circumpolar Survey 1978/79 1983/84 2nd C.S. 1989/90 3rd Circumpolar Survey 1994/95 800 700 600 500 400 300 200 100 0 Number of whales observed Line Transect Estimation Number of whales (thousands) • Drastical decrease in Minke whale estimates with small errors • Estimation is based on unverified assumptions • Survey plan frequently changed over decades • RMP underestimates uncertainty. • Why is 54%K limit? • Adaptive Learning! Uncertainty exists not only in whaling, but all fisheries. No lower stock limit USA Fishing is possible until stock collapse Japan Fishing coefficient, F Fisheries Management Rule; US and Japan = much looser than RMP 3 Overfished 2 Flimit (Fmsy) 1-a 1 Ftarget M 0 0 1 B t / BMSY 2 Conclusion: PP & AM are needed, PA is not. • Precautionary Principle for irreversible damage is indispensable. ⇔ USA do neither join Kyoto Protocol nor Convention of Biological Diversity • Precautionary Approach for sustainable use is unnecessary. • Adaptive Management is useful. Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 Conscious of Uncertainty 無知の知。不確実の知 • If BMSY >> MVP, we do not need precautionary approach for MSY. • Instead, we need to monitor Bt, catch quota is banned when Bt is below a critical level. • Even though BMSY is unknown, AM works well for sustainable use. • This is RMP. This is AM. Overview 今日の話題 • To avoid both over-exploitation and ban 乱獲も禁漁も避ける • Fallacy to Seek 0 Risk ゼロリスク探求症候群 • Precautionary Approach vs. Maximum Sustainable Yield 予防措置とMSY • Adaptive Management 順応的管理と不確実性 • Revised Management Procedure is an AM 改定管理方式は順応的管理 • PP & AM are needed, PA is not. 順応的管理があれば予防措置は不要 • Whaling & Ecosystems 捕鯨管理と生態系監視 Marine Ecosystems Concerns 海洋生態系への懸念 R. A. Myers & B. Worm (2002) Nature in press. “Rapid worldwide deple-tion of large predatory fish communities” …We conclude that declines of large predators that initially occurred in coastal regions, have extended throughout the global ocean, with potentially large consequences on ecosystems. Top predators are good indicator of ecosystems. Conclusion: Why is Management of Whaling Important? 1. Make a new method of stock estimation.資源量推定法の見直し 2. RMP is a good example of AM that is recommended by USA and Japan. RMPは日米推奨の順応的管理の好例 3. Ecosystem-based Monitoring 生態系 に与える影響を評価 Big project to Antarctic Area Monitoring.