webinar260413
TRANSCRIPT
Martha sucht…
www.alumniportal-deutschland.org
Webinar-Serie zur NachhaltigkeitTEIL I: Ökologische Konzepte
•22. April, 18-19 Uhr (UTC+2): Vom Wert der Arten: Biodiversität als Lebensgrundlage (auf Deutsch)
•26. April, 17-18 Uhr (UTC+2): Plenteous oceans? How we can win the battle against overfishing (in English)
•29. April, 18-19:30 Uhr (UTC+2): Alumni präsentieren ihre Forschungsprojekte (auf Deutsch/ Englisch)
Oceans full of Fish?Small Steps in the Right Direction
Rainer FroeseGEOMAR, Kiel, [email protected]
Webinar 26 April 2013
Overview
• Status of global fish stocks and fisheries
‚Stability‘ in world catches masks decline of fish stocks
4
Global Catches are Stagnating
Pauly and Froese, 2012
Global Effort Keeps Increasing
Pauly and Froese, 2012
Global Fish Stocks are Shrinking
If catches are stagnating
while effort is increasing
then fish stocks must be shrinking
Pauly and Froese, 2012
• 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
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Status of Global Fish Stocks 2009
9
Neue Bestände
Zusammengebrochen
Undeveloped
Developing
Fully exploited
Overexploited
Collapsed
Froese et al. Marine Biology 2012
10
Fisheries Can Provide More Protein ImmediatelyCarnivore Aquaculture is a Protein Sink
Four Terms • Biomass (B) is the body-weight of all fish in the
water• MSY is the Maximum Sustainable Yield
(= maximum catch) that can be taken from a population of fish (= stock) indefinitely
• Bmsy is the biomass that a fish stock must have, so that it can deliver the maximum sustainable yield MSY
• Fmsy is the fishing rate (the proportion of fish killed by fishing) resulting in Bmsy
MSY Is Good For You
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Below MSY Level
• Stressed ecosystems• Small fish• Small stock size• High fluctuations• Low, uncertain catch• High effort /cost• Low / no profit• Low impact impossible• MPAs problematic• Subsidies necessary
Above MSY Level
• Healthy ecosystems• Large fish• Large stock sizes• Low fluctuations• High, certain catch• Low effort /cost• High profit• Low impact possible• MPAs unproblematic• Subsidies not necessary
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If Stock Size is
European Stocks and Fisheries
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Status of all European Stocks
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Neue Bestände
Zusammengebrochen
Developing
Fully exploited
Undeveloped
Overexploited
Collapsed
Froese et al. Marine Biology 2012
Status of European Fish Stocks
17Landings from ICES 2010, MSY from Froese and Proelß 2010
Generic Harvest Control Rules for European FisheriesRainer Froese, Trevor A. Branch, Alexander Proelß, Martin Quaas, Keith Sainsbury & Christopher Zimmermann (2011)
Rules for sustainable and profitable fisheries based on 1) economic optimization of fisheries 2) honoring international agreements 3) true implementation of the precautionary principle 4) learning from international experiences 5) ecosystem-approach to fisheries management 6) recognizing the biology of European fish stocks
If these rules were applied, catches could increase by 63%
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Harvest Control Rule Schema
0
0.2
0.4
0.6
0.8
1
0 0.5 1 1.5 2
Biomass / B msy
Cat
ch /
MSY
B msy0.5 B msy 1.3 B msy
DepletedZone
OverfishingZone
BufferZone
TargetZone
MSY
0.91 MSY
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European Fisheries
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 0.5 1 1.5 2
Biomass / B msy
Catc
h / M
SY
B msy0.5 B msy 1.3 B msy
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Politics
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
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 decided upon its ‚compromise‘ position
• The European Parlament has agreed on an ambitious reform proposal
• Now a compromise has to be negotiated
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The Council Compromise
• Postpones sustainable fishing 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
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The Fisheries Question
• How much can we safely take from a fish population?
• How much mortality can we add without destroying the stock?
The Answer
Principles of Ecosystem-based Fisheries Management•Never take more than all other predators combined (typically 20% of stock)•To avoid collapse with high certainty, take less•Catch fish at the optimum size
Growth, Mortality and Reproduction
Froese & Pauly, 2013
Let them Grow and Multiply
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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
Excellent Agreement
Plot of MSY estimated by the Catch-MSY method versus full stock assessments for 48 stocksfrom the Northeast Atlantic. The broken line indicates the 1:1 relation while the dotted lines indicate ratios of 0.5 and 1.5, respectively.
Seafood Labels to the Rescue
• Definitions of ‚overfished‘ and ‚overfishing‘ that are compatible with international law
• 19% (FoS) to 31% (MSC) of certified stocks are overfished and suffer from ongoing overfishing
• But 61% (MSC) to 81% (FoS) of stocks with data are large enough and moderately exploited, which is better than the 15% in uncertified stocks
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Just Out
• Mismanagement of North Sea Cod: rebuilding was possible if scientific advice had been followed (Froese & Quaas 2012)
• Taking Rio+20 seriously: 50 – 70% of European stocks could be rebuilt to MSY-levels by 2015 (Froese & Quaas 2013)
• Is the costly European fisheries management necessary? Much simpler managgement may deliver better results (in prep).
Questions?
All paper PDFs are available fromwww.fishbase.de/rfroese
Rainer FroeseGEOMAR, Kiel, Germany