MARINE STRATEGY FRAMEWORK DIRECTIVE

GOOD 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

In the Commission Decision 2010/477/EU three criteria including methodological

standards 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

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

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 subregion

concerned.”

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.

Catch/Biomass ratio

Biomass indices

Size at first maturation

3. 1 Fishing pressure

F

Ref level: FMSY

3. 2 Reproductive

capacity

SSB

Ref level: SSBMSY

3. 3 Population age and

size distribution

95% percentileof length distribution

Prop of fish > mean size offirst sexual maturation

Mean maximum length across species

Criterion

Primary indicator

Secondary indicator

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

Roadmap to the GES assessment process

ApproachTheoretical concepts, criteria, methodologies for: Selection of commercial species Stocks with analytical assessments Species/stocks with info from monitoring programmes

Case Studies:

Bay of Biscay/IberiaBaltic Sea Celtic SeasNorth Sea Mediterranean

Synthesis: Different interpretations of GES

Assessment of current status against GES

30°E20°E10°E0°10°W20°W

50°N

40°N

30°N

20°N

Baltic Sea

Greater North Sea, incl. the Kattegat and the English Channel

Celtic Seas

Bay of Biscay and the Iberian Coast

Macaronesia

North-east Atlantic Ocean

Mediterranean Sea

Western Mediterranean Sea

Adriatic Sea

Ionian Sea and the Central Mediterranean Sea

Aegian-Levantine Sea

Regional Seas around Europe

Black Sea

Iceland Sea

Norwegian Sea

Barents Sea

Black Sea

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)

Uncertaintyincreases

Data-limited / model-poor

%Analytical 38Trends based 10Trends, survey only 39Catch only 13

Dr Carl O’Brien2012

Reduced quality and utility of advice for management

Descriptor 3The 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.

MSY ? – the maximum average long-term catch that may be taken from a fish stock under prevailing environmental conditions

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

Issues that ICES has not satisfactorily dealt with:

Data-limited / model-poor stocksWhat is FMSY?What is the current stock

exploitation?How should we manage future

exploitation?

Indeces

Categorisation of stocks into one of seven basis types:

1) Data rich stocks (quantitative assessments)2) Negligible landings stocks3) Stocks with analytical assessments that are treated

qualitatively4) Stocks for which survey indices (or unbiased CPUE)

indicate trends5) Stocks for which reliable catch data are available for

short time-series6) Truly data-poor stocks (landings only)7) Stocks caught in minor amounts as by-catch

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

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)

Category 3:Stocks with analytical assessments that are treated qualitatively

Requirements:

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)