Pastoors 2011 setting objectives for fisheries management


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  • Thank you for the invitation to speak about setting objectives for Fisheries ManagementMy name is Martin PastoorsAnd I guess I am talking in two different capacities.In the past I have been heavily involved in the process of generating biological advice for fisheries management in my role as chair of the Advisory Committee on Fishery Management of ICES, the International Council for the Exploration of the Sea. From 2008 onwards I have been involved in the setting up of a new research centre, called the Centre for Marine Policy. This centre has been established under the umbrella of Wageningen University and Research centre and aims to provide scientific support for integrated maritime policy. So in that capacity we am working on issues like maritime spatial planning, governance in fisheries policy, etc. Today I will speak about setting objectives for Fisheries ManagementIn my talk I want to address the role of science and society in the process of setting objectives, and the role of maximum sustainable yield als a potential objective for fisheries management. My basic
  • The main question that I want to address in this talk is: Is Maximum Sustainable Yield and appropriate target for fisheries management?Some have said that it is aiming too low, others claim that it is aiming too high.Some say it is a new element in fisheries management, others state that it has been around for ages alreadyI guess all are right in some way.
  • The main message of my talk is: Maximum Sustainable Yield (MSY) is not the magic bullet that will solve everything. However, it could provide a useful direction for travel, if I can use that metaphorical expression. MSY could used as a proxy for such a “lower” fishing mortality.
  • The important thing:It is not the numerical values that count, but rather the way they get established Is this done in an ivory tower of science?Or is this in a dialogue, with stakeholders at the table?Who is involved, is the process transparant and credible?Interaction, participation are key wordsThe absolute numerical value for MSY for a certain fish stock cannot be very precisely estimated. So as to create buy-in into a management plan that involves such a “lower” fishing mortality as an important elementThen it could prove an effective and efficient tool create sustainable fisheries.
  • The theory on MSY is relatively (sic) simple1. Basic idea: on average is you apply no fishing to a stock, you will have no catches. If you apply very high effort, you will fish down the stock and you will end up with zero catches as well. Somewhere in between is the Maximum Sustainable Yield that you could take from the resource. 2. If you then add the costs to the equation that are increasing with effort, you can also calculate the Maximum Economic Yield being the maximum difference between costs and revenue. Notice that the effort that gives Maximum Economic Yield is always lower than the effort that gives the maximum sustainable yield. 3. The third variant is the maximum social yield which is directly related to the effort in the sense that higher effort generates higher employment, which has a higher social yield. Note: The scientific background of the concept relates to the Yield (i.e. catch): “The highest theoretical equilibrium yield that can be continuously taken (on average) from a stock under existing (average) environmental conditions without affecting significantly the reproduction process.”(see FAO glossary).
  • But even though the theory is simpleThe practice is at least confusing. We have three different types of Maximum Yield things: economic, biological, socialBut there are alse three different concepts of Maximum Sustainable Yield.
  • Three different concepts associated with Maximum Sustainable Yield: Standard interpretation: Yield. The long term catch that can on average be taken from a stock. The second concept is MSY as a measure of stock biomass (often called Biomass at msy of Bmsy)The third concept is a level of effort or fishing mortality associated with MSY (often described as Fmsy). These three different uses of “MSY” are often not clearly distinguished in political agreements or policy descriptions.
  • The concept MSY is regulatory text is often ill described. For example the often quoted phrase: “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” from the Johannesburg agreement. Does this read like an interpretation of Biomass at MSY? The major discussion with regards to the role of MSY as a possible objective for fisheries management is the discussion between: rebuilding or maintaining fish stocks at or above Bmsy on the one hand and exploiting fish stocks with a mortality at or below Fmsy on the other hand. The first interpretation attempts to achieve a response in the natural system (e.g. a biomass of a certain size) whereas the second interpretation attempt to regulate the human impact on the natural system (through a maximum relative outtake).I would argue: be clear on what you intend to achieve.
  • The second issue relates to the essentially single species nature of MSYFor a single species (say: cod) it is to some extend doable to estimate MSY, Bmsy and Fmsy. But if we add herring to the equation: there is a simple interaction. Cod eat herring. So Bmsy for cod and Bmsy for herring could be difficult to achieve simultaneouslyIn addition, herring eat the eggs of cod. So there is a real feedback system. And herring also eat zooplankton. If there would be a small amount of zooplankton for some reason, achieving Bmsy for herring would be difficult. And there are seals. And seals eat cod. Suppose there are many seals: would we want to influence their abundance in order to achieve the Bmsy for cod? It is clear that the species interaction are particularly important for the biomass based MSY and Bmsy. This applies to a lesser extend to the fishing mortality Fmsy.
  • But perhaps the most serious issues is the fourth: can science really estimate or measure MSY?No not really. In practice the scientific advice of ICES is built upon proxies for FmsyDifferent technical terms are used like Fmed, F0.1 etc. I will not explain these concepts here (of course)The main point is that from a scientific perspective the most useful information for setting objectives is related to fishing mortality at MSY and not on MSY itself or on Bmsy.
  • Instead the main focus of fisheries policy – fisheries advice – was on the precautionary approach. Precautionary approach basically meant to avoid bad situations and did not necessarily want to achieve a good or optimal situation. We call this a risk-averse strategy. The precautionary approach shares with the MSY approach that it originates from the political domain (international treaties, code of conduct for responsible fisheries etc.) and gets specific interpretations in the scientific domain. In the case of the precautionary approach, the ICES interpretation of the regulations resulted in a proposed system of references points (limit reference points and precautionary reference points) that are still being used to guide the scientific advice on fishery management. However, as a drawback to this approach, Cadrin and Pastoors have shown in 2008 that it has resulted in an almost inverse precaution: only for the data-rich commercial stocks could reference points be estimated and applied in advice. For stocks with few data, like long-lived sharks and rays, deepwater species etc, the reference points could not be estimated and the advice often resorted to a status quo catch advice. The introduction of the precautionary approach was low on transparency and credibility because the basic approach was not explained. Uncertainties were not shown but were hidden behind a wall of technical details. This is science at the boundary with policy, and science taking on policy responsibilities like incorporating the implicit risk tolerance. There were no stakeholders involved in the process and the trust in the results has been low. Ref: Cadrin, S. X., and Pastoors, M. A. 2008. Precautionary harvest policies and the uncertainty paradox. Fisheries Research, 94: 367-372.
  • The role of science in the field of fisheries management is one of providing information. Information on what we know and what we do not know. Information on the trade-offs between different options. Information on risks associated with certain strategies. Based on my experience in the field, I would argue against positioning science in the role of judging what is right or wrong, what is sustainable and what is not sustainable. What is MSY and what is not MSY. In the end this comes down to societal and political process of weighting different sources of information and different perspectives on the issues. The scientific information is one of the elements to be weighted but not necessarily the only decisive argument for or against a choice. The type of science that is carried out in this field is such that it cannot establish simple facts. The systems are complex and cannot be fully known. In that situation, science can summarize the best available knowledge but it should at all times be completely transparant how the information was put together and where the strengths and weaknesses lie.
  • In recent years, Maximum Sustainable Yield (MSY) has been introduced as a new element in EU fisheries policy.Before, say, 2010, MSY was not a prominent feature in the EU Common Fisheries Policy. And also,k for several decades it has not been the basis for scientific advice by ICES to the European Union.
  • For the previous it is already clear that there are a number of “issues” with MSY.I would like to address three issues here: The Unclear meaning of the concept in regulatory textsThe Single species approach implicit in MSY, andThe estimation aspects
  • The recent move to MSY in both policy and advice, has often attributed to the Johannesburg Summit 2002In fact, it was already part of the law of the sea convention in 1982 and can even be traced back to earlier agreements in the 1950s. The main change in the Johannesburg Declaration of 2002 was that for the first time a year was associated with achieving some sort of MSY: 2015But what is this MSY that we are talking about?Mesnil, B. 2012. The hesitant emergence of maximum sustainable yield (MSY) in fisheries policies in Europe. Marine Policy, 36: 473-480.
  • An example from the scientific literature, based on a paper by Froese et al in 2010. If you would calculate the Biomasses at MSY for a number of important commercial species in the North Sea you get the column on the left. In red the flatfishes, in blue the predatory fishes and in green the prey fishes. For comparison, on the right hand side the estimated current biomasses of these species. The different is a factor of 7, i.e. 700%. I would not be able to explain such a leap of biomass. I would make the claim that we CAN calculate some sort of Bmsy of all the species individually, but that we CANNOT add them up to make a realistic approximation of a future ecosystem.
  • The third issue is very much related to the previous issue: essentially the MSY approaches that are currently used apply to equilibrium situations. And one thing we can say about marine systems is that they are often in a state of flux and change over time. Of course this is closely related to the changes in species composition in the ecosystem. Fewer cod in the system means more herring and shrimp. There are many feedback loops that interfere with the equilibrium assumptions.
  • Pastoors 2011 setting objectives for fisheries management

    1. 1. Public Hearing, European Parliament, Committee on Fisheries “Management of fishery resources and fishing fleet” Brussels, 23 November 2011 Setting objectives for fisheries managementthe role of science and society Martin Pastoors
    2. 2. Q:Is Maximum Sustainable Yield (MSY) an appropriate target for fisheries management?
    3. 3. Maximum Sustainable Yield (MSY) isnot the magic bullet for everything ... but it could provide a direction for travel
    4. 4. it is not the numerical values that count but the way they get established
    5. 5. The theory is (relatively) simple Maximum Sustainable Yield Maximum Economic Yield Maximum Social Yield Catch MSYRevenue MEY MSocY Effort
    6. 6. ... but the practice is (at least) confusing
    7. 7. Three types of “MSY” MSY Fmsy Bmsy Maximum Fishing BiomassSustainable mortality Yield
    8. 8. MSY in regulations is ill-described“maintain or restore stocks to = Bmsy?levels that can produce themaximum sustainable yield withthe aim of achieving these goalsfor depleted stocks on an urgentbasis and where possible not laterthan 2015” Johannesburg declaration, 2002
    9. 9. MSY is a single-species concept:how to deal with ecosystem links? Seal Cod Herring Zoo- plankton
    10. 10. Can science estimate “MSY”? No, not really...but we can come up with proxies Fmed, F0.1, Fmax, Fmt, Fsim
    11. 11. Lessons from the introduction of the precautionary approach
    12. 12. MSY approach = Fish less?
    13. 13. Reference points for MSY areapproximations, not carved in stone
    14. 14. Fisheries science can inform decision- making but cannot make decisions Should not
    15. 15. Use the MSY concept: get stakeholders talking,move in the right direction
    16. 16. Extra
    17. 17. Maximum Sustainable Yield is a“new” element in EU fisheries policy
    18. 18. “Issues” with MSY• Unclear meaning• Single species• Estimation aspects
    19. 19. MSY became prominent through the Johannesburg Declaration 2002
    20. 20. Maximum Economic Yield (MEY) is achieved at lower effort thanMaximum Sustainable Yield (MSY) Catch MSY Revenue MEY FMEY < FMSY Effort
    21. 21. Adding up Bmsy is problematic Flatfish Predators x 7.3 Prey Bmsy Current biomassExample: North Sea fish stocks Charts based on: Froese et al 2010
    22. 22. 3. MSY is an equilibrium approach applied to a dynamic system