Transcript EU Fisheries Management: MSY and Beyond

Fishing in National and International
Waters: MSY and Beyond
Rainer Froese
GEOMAR, Kiel, Germany
[email protected]
2nd Sustainable Oceans Conference: Reconciling Economic Use and Protection
New York, 13th July 2012
Overview
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Existing Knowledge: FishBase and AquaMaps
Global Fisheries and Aquaculture
MSY is good for you
How to implement MSY fisheries?
What about ecosystem-based fisheries?
Conclusions
Knowledge Bases
www.fishbase.org
www.fishbase.org
www.fishbase.org
www.fishbase.org
www.fishbase.org
www.aquamaps.org
www.futureoceanatlas.de
Global Fisheries and Aquaculture
Fisheries Can Provide More Protein Immediately
Carnivore Aquaculture is a Protein Sink
MSY Is Good For You
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Below MSY Level
Above MSY Level
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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
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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The General Problem
• Over 4,000 species of fishes are harvested
from the wild globally (FishBase 02/2012)
• Full stock assessments are available for only a
few hundred species
The Solution
General principles combined with incomplete
knowledge are sufficient for reasonable
management
(Lessons learned after 30+ years of managing the
Great Barrier Reef, Josh Gibson, pers. comm., 21.6.2012)
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:
• Take account of species interactions
• Never take more than what all other predators
combined are taking
• To avoid collapse with high certainty, take less
than the other predators
– For regular fish, take ¾ of natural mortality
– For forage fish, take ½ of natural mortality
Pikitch et al. 2012
How to Estimate Natural Mortality?
• From decrease of numbers by age class (only
about 200 studies in FishBase; Z = F +M)
• From growth parameters
• From longevity
• From maximum size
How about Data-Poor Stocks?
• Knowing the fraction of the stock that can be
fished sustainably (about 20%) 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
2012
Excellent Agreement
Plot of MSY estimated by the Catch-MSY method versus full stock assessments for 48 stocks
from the Northeast Atlantic. The broken line indicates the 1:1 relation while the dotted lines
indicate ratios of 0.5 and 1.5, respectively.
Conclusions
• We know more than we know
• Carnivore aquaculture is a problem and
not a solution
• The MSY concept is good and binding
• MSY can be estimated for all stocks
• Ecosystem-based fisheries management
is doable right now
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Main Conclusion
• Compared with other Ocean problems,
Overfishing can be fixed within a few years
at low cost with high gains
• Rio+20 (Article 168) provides an excellent
basis
• Europe could take the lead
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References
• FishBase: www.fishbase.org
• AquaMaps: www.aquamaps.org, www.futureoceanatlas.de
• Froese, R. and A. Proelß. 2010. Rebuilding fish stocks no later than 2015:
will Europe meet the deadline? Fish and Fisheries 11:194-202
• Froese, R., T.A. Branch, A. Proelß, M. Quaas, K. Sainsbury and C.
Zimmermann. 2011. Generic harvest control rules for European fisheries.
Fish and Fisheries 12:340-351
• Froese, R. and M. Quaas. 2011. Three options for rebuilding the cod stock
in the eastern Baltic Sea. Marine Ecology Progress Series 434:197-2011.
• Martell, S. and R. Froese. 2012. A simple method for estimating MSY from
catch and resilience. Fish and Fisheries, doi:10.1111/j.14672979.2012.00485.x
• Pikitch, E. et al. 2012. Little fish, big impact. Managing a crucial link in
ocean food webs. Lenfest Ocean Program. Washington, DC. 108 pp.
This presentation will be available for download at
www.fishbase.de/rfroese
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Thank You
Rainer Froese
GEOMAR, Kiel
[email protected]
www.fishbase.de/rfroese
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