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Setting objectives for fisheries management
the role of science and society
Martin Pastoors
Public Hearing, European Parliament, Committee on Fisheries“Management of fishery resources and fishing fleet”
Brussels, 23 November 2011
Q:Is Maximum Sustainable Yield (MSY)
an appropriate target for fisheries management?
Maximum Sustainable Yield (MSY) is not the magic bullet for everything
... but it could provide a direction for travel
it is not the numerical values that count but the way they get established
The theory is (relatively) simple
Catch Revenue
Effort
MSY
MEY MSocY
Maximum Sustainable Yield
Maximum Economic Yield
Maximum Social Yield
Costs
... but the practice is (at least) confusing
Fishing mortality
Three types of “MSY”
MaximumSustainable
Yield
Fmsy Bmsy
BiomassMSY
MSY in regulations is ill-described
“maintain or restore stocks to levels that can produce the maximum sustainable yield with the aim of achieving these goals for depleted stocks on an urgent basis and where possible not later than 2015”
Johannesburg declaration, 2002
= Bmsy?
MSY is a single-species concept: how to deal with ecosystem links?
Seal
Cod Herring
Zoo-plankton
Can science estimate “MSY”?
No, not really
...but we can come up with proxies
Fmed, F0.1, Fmax, Fmt, Fsim
Lessons from the introduction of the precautionary approach
MSY approach = Fish less?
Reference points for MSY are approximations, not carved in stone
Fisheries science can inform decision-making but cannot make decisions
Should not
Use the MSY concept:get stakeholders talking,
move in the right direction
Extra
Maximum Sustainable Yield is a “new” element in EU fisheries policy
“Issues” with MSY
• Unclear meaning• Single species• Estimation aspects
MSY became prominent through the Johannesburg Declaration 2002
Maximum Economic Yield (MEY) is achieved at lower effort than
Maximum Sustainable Yield (MSY)
Catch Revenue
Effort
MSY
MEY Costs
FMEY < FMSY
Theory
Adding up Bmsy is problematic
Charts based on: Froese et al 2010Example: North Sea fish stocks
Bmsy Current biomass
Flatfish
Predators
Prey
x 7.3
3. MSY is an equilibrium approach applied to a dynamic system