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1 Fisheries sustainability – CFP directions, MSFD descriptors and CSI Poul Degnbol Head of ICES advisory programme / ETC/W Marine and Coastal EEA/EIONET workshop 25/10 1010 EEA Copenhagen
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Fisheries sustainability From avoiding something bad –Precautionary approach – safe biological limits To avoiding somthing bad AND rebuild marine ecosystems –Maximum Sustainable Yield (MSY) with precaution about population sizes
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Precautionary approach Do not reduce the population to a level where reproduction may be impaired Safe Biological Limits
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Cod in the North Sea Recruitment Parent stock Yield Fishing mortality
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B lim Impaired recruitment ?? “Outside safe biological limits” North Sea cod Safe biological limits
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Cod in the North Sea Recruitment Parent stock Yield Fishing mortality
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Safe biological limits - status
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MSFD descriptor 3 Populations of all commercially exploited fish and shellfish are within safe biological limits, exhibiting a population age and size distribution that is indicative of a healthy stock.
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Maximum Sustainable Yield Maintining (or rebuilding) stocks at high productivity –Rebuilding marine ecosystems (from a state of gross overexploitation) –Delivering services to society (food and economic benefits)
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Maximum sustainable yield Concept developed in the 1930s The productivity of a population is maximum at intermediate population sizes Hjort 1930
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B&H 1956 The productivity of a fish population is a balance between individual growth and mortality Fisheries yield will have a maximum Beverton and Holt 1956
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MSY Fisheries yield depends on fishing mortality and selectivity Beverton 1953
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Present fishing mortality North Sea cod Maximum sustainable Yield (MSY)
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MSY vs SBL Safe biological limits is about avoiding to impair stock reproduction MSY is about maintaining fish stocks well above safe levels and thereby maintain ecosystem services (ecosystem structure, diversity, societal benefits (food, economic opportunities) MSY is (in the present situation of overfishing) about reducing fishing pressure importantly and thereby rebuild fish stocks well above safe levels
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Uptake in management MSY seems an easy basis for fisheries management –Relates to management instruments – TAC/effort and selectivity –Who would object to something which is ’maximum’ and ’sustainable’ ? Introduced formally in management from 1955 Increasingly influential as the conceptual basis for fisheries management – formalised in UN Law of the Sea and UN stocks agreement 1995
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Critique Larkin 1977: –Puts populations on too much risk –Does not consider spatial variation –Only considers target stock –Considers only benefits, not costs Later critique –Does not consider other elements of ecosystem sensitive species Habitat impacts Ecosystem ’health’ – food webs, biodiversity –Relates to equilibrium and a constant nature – this never applies in reality –Focus limited to biological sustainability Social sustainability? Economic optimality not equal to MSY
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MSY at the policy forefront UNCLOS UN fish stocks agreement 1995 WSSD 2002 EC MSY policy 2006 Stated as core conservation target in EC Green Paper on Reform of the Common Fisheries Policy 2009 Societal objectives firmly based on ’MSY’ Which science has rejected in its classical shape
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Dilemma Classical MSY concept flawed Political objectives refer to ’MSY’ How to reinterpret ’MSY*?
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Reinterpreting ’MSY’ Interpretation: policy guidelines referring to ’MSY’ refer to the need to ensure optimal ecosystem services on the long term (not to the classical MSY concept) ’MSY’ must be within – not replacing other boundaries: –Precautionary approach (”safe biological limits”) –Ecosystem approach
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MSY limits Precautionary approach: MSY limited by limit stock size Ecosystem approach: MSY limited by unacceptable ecosystem impacts (biodiversity, habitats, ecosystem health)
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State of Stocks: MSY
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22 1. Biological diversity is maintained. The quality and occurrence of habitats and the distribution and abundance of species are in line with prevailing physiographic, geographic and climatic conditions. 3. Populations of all commercially exploited fish and shellfish are within safe biological limits, exhibiting a population age and size distribution that is indicative of a healthy stock. 4. All elements of the marine food webs, to the extent that they are known, occur at normal abundance and diversity and levels capable of ensuring the long-term abundance of the species and the retention of their full reproductive Capacity. 6. Sea-floor integrity is at a level that ensures that the structure and functions of the ecosystems are safeguarded and benthic ecosystems, in particular, are not adversely affected. MSFD descriptors with important fisheries impacts
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Dilemma – MSFD vs CFP Fisheries management is an exclusive community competence – MSFD objectives involving fisheries can only be implemnted through CFP measures MSFD refers to ’safe biological limits’ while CFP moving ahead to stricter conservation targets (MSY within the precautionary approach) What to do?
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Call the experts
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Decide (fishing pressure) Primary indicator. The primary indicator for the level of pressure of the fishing activity is the following: Fishing mortality (F)(3.1.1) Achieving good environmental status requires that F values are equal to or lower than FMSY, the level capable of producing Maximum Sustainable Yield (MSY). This means that in mixed fisheries and where ecosystem interactions are important, long term management plans may result in exploiting some stocks more lightly than at FMSY levels in order not to prejudice the exploitation at FMSY of other species[1].[1] [1]Communication "Implementing sustainability in EU fisheries through maximum sustainable yield", COM (2006) 360 of 4.7.2006. [1]
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Decide (biomass) Spawning Stock Biomass (SSB)(3.2.1) This is estimated from appropriate analytical assessments based on the analysis of catch at age or at length and ancillary information. Where an analytical assessment allows the estimation of SSB, the reference value reflecting full reproductive capacity is SSBMSY, i.e., the spawning stock biomass that would achieve MSY under a fishing mortality equal to FMSY. Any observed SSB values equal to or greater than SSBMSY is considered to meet this criterion.
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Future status indicators? No stocks fished at or below F MSY No of stocks at or above SSB MSY –but SSB MSY not known presently and is not robust to environmental changes Weighting of stocks ? –they range 3 orders of magnitude in biomass Do not use catch as weighting!
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Cod in the North Sea Recruitment Parent stock Yield Fishing mortality
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Euroostat sustainable development 2009 report
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Other indicators in CFP Data Collection Framework (Council reg 199/2008, 665/2008; Com decision 2008/949) Implementation regulation (2008/949, Appendix XIII) defines 9 indicators for the ecosystem impacts of fisheries
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DCF indicators Environmental indicators to measure the impacts of fisheries on marine ecosystems 1 Conservation status of fish 2 Proportion of large fish 3 Mean maximum length of fishes 4 Size at maturation of exploited fish species 5 Distribution of fishing activities 6 Aggregation of fishing activities 7 Areas not impacted by mobile bottom gears 8 Discarding rates of commercially exploited species 9 Fuel efficiency of fish capture Contributes to MSFD descriptor 1 (biodiversity), 2 (food webs), 3 (fish stocks), 6 (sea floor integrity) Implementation regulation DCF (Commission decision 2008/949, Appendix XIII)
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32 Thank you!
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