Marine Strategy Framework Directive Good Environmental Status (GES) on Descriptor 3

1. Marine Strategy Framework DirectiveGood Environmental Status (GES) on Descriptor 3 Descriptor 3 for determining Good Environmental Status (GES) under the MSFD was defined as “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”Directive 2008/56/EC, Annex I

2. In the Commission Decision 2010/477/EU three criteria including methodologicalstandards were described for this descriptor. • methodological standards are defined • methods developed and agreed in the framework of European or international conventions • Criterion 3.1 Level of pressure of the fishing activity • • Primary indicator: Indicator 3.1.1 Fishing mortality (F) • • Secondary indicator (if analytical assessments yielding values for F are not • available): Indicator 3.1.2 Ratio between catch and biomass index (hereinafter • ‘catch/biomass ratio’) • Criterion 3.2 Reproductive capacity of the stock • • Primary indicator: Indicator 3.2.1 Spawning Stock Biomass (SSB) • • Secondary indicator (if analytical assessments yielding values for SSB are • not available): Indicator 3.2.2 Biomass indices

3. Descriptor 3 • Criterion 3.3 Population age and size distribution • • Primary indicator: Indicator 3.3.1 Proportion of fish larger than the mean • size of first sexual maturation • • Primary indicator: Indicator 3.3.2 Mean maximum length across all species • found in research vessel surveys • • Primary indicator: Indicator 3.3.3 95% percentile of the fish length distribution • observed in research vessel surveys • • Secondary indicator: Indicator 3.3.4 Size at first sexual maturation

4. Following the MSFD in that “Each Member State shouldtherefore develop a marine strategy for its marine waters which, while being specificto its own waters, reflects the overall perspective of the marine region or subregionconcerned.”

5. 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. 3. 3 Population age and size distribution 3. 1 Fishing pressure 3. 2 Reproductive capacity Criterion Prop of fish > mean size of first sexual maturation Primary indicator F Ref level: FMSY SSB Ref level: SSBMSY Mean maximum length across species 95% percentile of length distribution Secondary indicator Catch/Biomass ratio Biomass indices Size at first maturation

6. Roadmap to the GES assessment process Selection of commercially exploited (shell)fish populations Stocks for which primary indicators and reference levels are available Species for which no reference levels are available Interpretation of GES Assessment of current status in relation to GES

7. Approach Theoretical concepts, criteria, methodologies for: Selection of commercial species Stocks with analytical assessments Species/stocks with info from monitoring programmes Case Studies: Bay of Biscay/Iberia Baltic Sea North Sea Celtic Seas Mediterranean Black Sea Synthesis: Different interpretations of GES Assessment of current status against GES

8. Quality of informationStock Status • Robust quantitative assessment • Preliminary quantitative assessment • Estimates of fishing mortality / exploitation (F) from catch curves (age / length data) • Trends in catch-per-unit-effort (CPUE) Uncertainty increases

9. Data-limited / model-poor • Reduced quality and utility of advice for management Dr Carl O’Brien 2012

10. MSY ? – the maximum average long-term catch that may be taken from a fish stock under prevailing environmental conditions Descriptor 3 The data available are inadequate to: • estimate the current population size; and • the catch resulting from fishing at a desired F. • Advice on catches only? • ICES’ MSY approach calls for a determination of the status of exploitation relative to FMSY and considerations of the stock trend. Without a radical change in approach … implies that approximately 60% of the 188 (158) stocks will have no useful scientific advice w.r.t. MSY

11. Issues that ICES has not satisfactorily dealt with: • Data-limited / model-poor stocks • What is FMSY? • What is the current stock exploitation? • How should we manage future exploitation?

13. Indeces

14. Category 7 – stocks that are part of stock complexes and are primarily caught as by-catch species in other targeted fisheries. The development of indicators may be most appropriate for such stocks; e.g. NS brill in the targeted NS plaice and sole fishery. Trends/Ref points • Categorisation of stocks into one of seven basis types: • Data rich stocks (quantitative assessments) • Negligible landings stocks • Stocks with analytical assessments that are treated qualitatively • Stocks for which survey indices (or unbiased CPUE) indicate trends • Stocks for which reliable catch data are available for short time-series • Truly data-poor stocks (landings only) • Stocks caught in minor amounts as by-catch

15. Category 3:Stocks with analytical assessments that are treated qualitatively • Requirements: • Trends/Ref points • relative management advice on the direction and relative scale of the changes required to achieve targets. • Category 4: Stocks for which survey indices (or unbiased CPUE) indicate trends Requirements: • the time series that should be used to determine the status of the stock and provide catch advice. • Category 5: Stocks for which reliable catch data are available for short time-series - Under consideration(further assessments)

16. What are the prospects for the future? • On-going studies; • What is FMSY? • life history characteristics include, among other things, longevity, fecundity and recruitment variability • What is the current stock exploitation? • Harvest ratio proxies and survey (DCF / FSP) catch curves • How should we manage future exploitation? • simple trend-based rules (survey / catch)