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Indicator Specification

Status of marine fish and shellfish stocks in European seas

Indicator Specification
  Indicator codes: CSI 032 , MAR 007
Published 03 Apr 2018 Last modified 04 Dec 2019
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The indicator tracks both the status of commercial fish stocks in European regional seas and the pressure exerted by fisheries on those stocks, as well as the quality of the information available. To that end, the following is reported: the status of marine fish and shellfish stocks based on the current level of exploitation and reproductive capacity; the importance of the (sub-)region, reflected by the total landings (as a proxy of catch) of fish from commercial fisheries in European seas per MSFD (sub-)region, and the availability of appropriate information for the status assessment, as reflected by the proportion of those landings covered by quantitative stock assessments (i.e. the proportion providing the required indicators and their reference levels). Status of marine fish and shellfish stocks The MSFD requires 'Good Environmental Status' to be achieved by 2020 (EC, 2008). According to the MSFD (Descriptor 3), three criteria are relevant to determining if a fish or shellfish stock has achieved GES: Sustainable exploitation: sustainably exploited stocks are stocks for which F is at or below levels that deliver MSY, i.e. F ≤ F MSY . Thus, a stock is considered to have been assessed against this criterion only if values for F and F MSY  are available ,  and the stock is considered to have achieved GES only if F ≤ F MSY . Reproductive capacity: in areas assessed by the ICES, the criterion for sustainable reproductive capacity (SSB > SSB MSY ) has been modified, for pragmatic reasons, to SSB > MSY B trigger . SSB is consistently provided as part of ICES stock assessments, i.e. of the North-East Atlantic and Baltic Sea, but not, for the most part, by STECF assessments, i.e. of the Mediterranean and Black Sea stocks. Similarly to the above, a stock is considered to have been assessed against this criterion if values of SSB and a good proxy for SSB MSY are available, and the stock is considered to have achieved GES only if SSB > SSB MSY  (or appropriate proxy). Healthy age and size structure: in this case, the assumption is that a stock with sufficient numbers of old and large fish is healthy and that the more older/larger fish there are, the better the health of the fish stock. However, this criterion is not sufficiently developed and no threshold for GES is known for this criterion. Therefore, it is not included. This has resulted in four assessment categories: Not: no sufficient information available to assess status; F: status assessed based only on F and F MSY; SSB: status assessed based only on SSB and SSB MSY (or some proxy, i.e. MSY B trigger ); F & SSB: status assessed based on both F and SSB. Total landings Landings are based on the ICES Official Nominal Catches data set and the Food and Agriculture Organization of the United Nations (FAO) 'GFCM (Mediterranean and Black Sea) capture production' annual statistics. The statistics comprise catch data reported by country, by species and by area or division. Only some of the species/taxa in the landings data can be considered 'commercial fish', which, for assessment purposes, may consist of several stocks. Only some of these stocks are covered by quantitative stock assessments such that their status can be assessed based on the above criteria. Stocks In the North-East Atlantic area, stocks are generally defined based on biological criteria and knowledge of population migration, mixing and spawning areas. For example, cod is currently considered to form eight different stocks, i.e. Sub-areas I and II (Northeast Arctic), Division Va (Iceland grounds), Sub-division Vb1 (Faroe Plateau), Sub-area IV and Divisions VIId and IIIa West, Sub-divisions 22-24 (Western Baltic Sea), Division VIa (West of Scotland), Division VIIa (Irish Sea) and Divisions VIIe-k (Western English Channel), between which mixing is negligible. These eight stocks cover five MSFD (sub-)regions, i.e. the Baltic Sea, the North Sea, the Celtic Sea, the Barents Sea and the Icelandic waters. In the Mediterranean and Black Sea, on the other hand, stocks are mostly defined by management area because of a lack of biological knowledge. Because these stocks are based on a specific geographical area, most can be attributed to a specific MSFD (sub-)region.

Assessment versions

Published (reviewed and quality assured)
  • No published assessments
 

Rationale

Justification for indicator selection

Commercial fish and shellfish provide most of the seafood derived from European waters and, if sustainably exploited, they could be a continuous source of healthy protein. However, the heavy exploitation of fish and shellfish can affect their reproductive capacity and thus their potential for recovery. In order to achieve sustainability, the levels of exploitation and reproductive capacity need to be analysed in an assessment of the status of marine fish and shellfish in Europe. The fact that only those stocks for which regular quantitative stock assessments are conducted can be included in such a status assessment means that it is important to show what proportion of commercial species is covered by quantitative stock assessments.   

Therefore, this indicator consists of three parts:

  • an overview of the status of assessed fish stocks per MSFD (sub-)region and its trend over time, which is based on two criteria:
    • a sustainable level of exploitation (assessed by F);
    • reproductive capacity not being compromised (assessed by SSB);
  • the proportion of assessed fish stocks that achieves two of the three GES criteria per MSFD (sub-)region, based on stock assessments by the International Council for Exploration of the Sea (ICES) and the Scientific, Technical and Economic Committee for Fisheries (STECF);
  • the proportion of the total catch in the MSFD (sub-)regions of Europe covered by quantitative stock assessments conducted by the ICES and the General Fisheries Commission for the Mediterranean (GFCM).

Scientific references

Indicator definition

The indicator tracks both the status of commercial fish stocks in European regional seas and the pressure exerted by fisheries on those stocks, as well as the quality of the information available. To that end, the following is reported:

  • the status of marine fish and shellfish stocks based on the current level of exploitation and reproductive capacity;
  • the importance of the (sub-)region, reflected by the total landings (as a proxy of catch) of fish from commercial fisheries in European seas per MSFD (sub-)region, and the availability of appropriate information for the status assessment, as reflected by the proportion of those landings covered by quantitative stock assessments (i.e. the proportion providing the required indicators and their reference levels).

Status of marine fish and shellfish stocks

The MSFD requires 'Good Environmental Status' to be achieved by 2020 (EC, 2008). According to the MSFD (Descriptor 3), three criteria are relevant to determining if a fish or shellfish stock has achieved GES:

  • Sustainable exploitation: sustainably exploited stocks are stocks for which F is at or below levels that deliver MSY, i.e. F ≤ FMSY. Thus, a stock is considered to have been assessed against this criterion only if values for F and FMSY are availableand the stock is considered to have achieved GES only if F ≤ FMSY.
  • Reproductive capacity: in areas assessed by the ICES, the criterion for sustainable reproductive capacity (SSB > SSBMSY) has been modified, for pragmatic reasons, to SSB > MSY Btrigger. SSB is consistently provided as part of ICES stock assessments, i.e. of the North-East Atlantic and Baltic Sea, but not, for the most part, by STECF assessments, i.e. of the Mediterranean and Black Sea stocks. Similarly to the above, a stock is considered to have been assessed against this criterion if values of SSB and a good proxy for SSBMSY are available, and the stock is considered to have achieved GES only if SSB > SSBMSY (or appropriate proxy).
  • Healthy age and size structure: in this case, the assumption is that a stock with sufficient numbers of old and large fish is healthy and that the more older/larger fish there are, the better the health of the fish stock. However, this criterion is not sufficiently developed and no threshold for GES is known for this criterion. Therefore, it is not included.

This has resulted in four assessment categories:

  • Not: no sufficient information available to assess status;
  • F: status assessed based only on F and FMSY;
  • SSB: status assessed based only on SSB and SSBMSY (or some proxy, i.e. MSY Btrigger);
  • F & SSB: status assessed based on both F and SSB.

Total landings

Landings are based on the ICES Official Nominal Catches data set and the Food and Agriculture Organization of the United Nations (FAO) 'GFCM (Mediterranean and Black Sea) capture production' annual statistics. The statistics comprise catch data reported by country, by species and by area or division.

Only some of the species/taxa in the landings data can be considered 'commercial fish', which, for assessment purposes, may consist of several stocks. Only some of these stocks are covered by quantitative stock assessments such that their status can be assessed based on the above criteria.

Stocks

In the North-East Atlantic area, stocks are generally defined based on biological criteria and knowledge of population migration, mixing and spawning areas. For example, cod is currently considered to form eight different stocks, i.e. Sub-areas I and II (Northeast Arctic), Division Va (Iceland grounds), Sub-division Vb1 (Faroe Plateau), Sub-area IV and Divisions VIId and IIIa West, Sub-divisions 22-24 (Western Baltic Sea), Division VIa (West of Scotland), Division VIIa (Irish Sea) and Divisions VIIe-k (Western English Channel), between which mixing is negligible. These eight stocks cover five MSFD (sub-)regions, i.e. the Baltic Sea, the North Sea, the Celtic Sea, the Barents Sea and the Icelandic waters.

In the Mediterranean and Black Sea, on the other hand, stocks are mostly defined by management area because of a lack of biological knowledge. Because these stocks are based on a specific geographical area, most can be attributed to a specific MSFD (sub-)region.

Units

The units used in this indicator are tonnes, as well as the number and proportion of catch in tonnes for assessed stocks/non-assessed stocks. The assessment information is expressed as the proportion of landings (tonnes) covered by assessed stocks. The status of the assessed stocks can be expressed as the proportion of the number of assessed fish and shellfish stocks or the proportion of landings of fish and shellfish stocks.

 

Policy context and targets

Context description

The scope of the CFP includes the conservation of marine biological resources and the management of fisheries that target them. To that end, the CFP should adapt exploitation rates to ensure that, within a reasonable time frame, the exploitation of marine biological resources allows the restoration and maintenance of populations of harvested stocks above levels that can produce the MSY. This should be achieved by 2015 or no later than 2020.

The aim of the MSFD is to achieve a GES of the EU's marine waters by 2020 and to protect this resource, upon which marine-related economic and social activities depend. The MSFD enshrines in a legislative framework the ecosystem approach to the management of human activities that have an impact on the marine environment, integrating the concepts of environmental protection and sustainable use.

In order to achieve its goal, the directive establishes European marine regions and sub-regions on the basis of geographical and environmental criteria. The MSFD significantly strengthens Member States’ competences and responsibilities to maintain or achieve GES for all exploited fish and shellfish stocks inside territorial waters and exclusive economic zones (EEZs) with common goals. Three criteria in relation to GES have been identified for commercial fish and shellfish:

  • the level of exploitation;
  • reproductive capacity;
  • a healthy age and size distribution.

These requirements for GES, according to the MSFD, are aligned with the requirement for MSY for both the 'level of exploitation' and 'reproductive capacity' criteria. The 'healthy age and size distribution' criterion is not yet sufficiently developed.

Targets

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 being produced no later than 2020 (EC, 2008, Annex I).

All EU fish and shellfish stocks should be fished to produce a MSY no later than 2015 (EC, 2006). This implies that the targets are F ≤ FMSY and SSB ≥ SSBMSY. MSY Btrigger is used as a best proxy for SSBMSY.

Related policy documents

Key policy question

How far is Europe in achieving a robust assessment for Good Environmental Status of its fish and shellfish stocks?

 

Methodology

Methodology for indicator calculation

North-East Atlantic Ocean and Baltic Sea

For the North-East Atlantic Ocean (considering the sub-regions) and Baltic Sea, this CSI 032 indicator is calculated using the ICES stock database. The ICES stock database consists of 174 stocks, and provides information, by stock and by year, on a number of variables. The period for which this information is available varies depending on the stock.

Proportion of assessed stocks

Initially, the two criteria used to determine the status of commercial fish stocks are:

  • exploited sustainably, consistent with high long-term yields;
  • have full reproductive capacity.

F and SSB, in combination with an MSY-based reference value, are the most appropriate metrics for these two criteria. The metrics used for F and SSB may differ between stocks. It is preferable for F to be expressed as fishing pressure and SSB as stock size. This may result in a different number of stocks being assessed for each metric. 

Total catch in MSFD (sub-)regions

Stocks are assigned to an MSFD region based on the ICES sub-areas and divisions mentioned in the Stocks sub-section of the Indicator description. Note that the MSFD regions assigned to fish stocks are not conclusive and may change after further consultation. As catches are assigned to stock level rather than ecoregion level, catches may need to be redistributed over the different ecoregions. The ICES Official Nominal Catches data set is used to calculate proportions in order to redistribute stock catches over the different ecoregions. Catches are selected for species and areas as described in the stock description for stocks that cover more than one ecoregion. Selected catches are assigned to MSFD ecoregion. Thereafter, the proportion of a catch in each ecoregion, in relation to the total selected catch, is calculated. The total catch by ecoregion is used to calculate the proportion, to redistribute stock catches over ecoregions.

Total catch data are extracted from the ICES Official Nominal Catches data set and are assigned to the different MSFD regions based on area. The total catch for non-assessed stocks by ecoregion is calculated by subtracting total stock catches by ecoregion from the total catches by ecoregion.

GES

The status of commercial species per MSFD (sub-)region is assessed based on all stocks for which the required information on F and/or SSB is available. For each region, the proportion of stocks that fulfil one (only F or only SSB if both criteria are known), both (F and SSB) or either one (F or SSB if only a single criterion is known) of the MSFD criteria for GES is calculated. Thus, the four different categories are:

  • F only: stocks for which only F information is available and that fulfil the MSFD criterion for F GES;
  • SSB only: stocks for which only SSB information is available and that fulfil the MSFD criterion for SSB GES;
  • F and SSB: stocks for which F and SSB information is available and that fulfil the MSFD criteria for F GES and SSB GES;
  • F or SSB: stocks for which F and SSB information is available and that fulfil the MSFD criterion for F GES or SSB GES.

Mediterranean and Black Seas

Proportion of assessed stocks

For the Mediterranean and Black Seas, information on assessed stocks is extracted from STECF Mediterranean and Black Sea Working Group reports. As assessments are carried out in a multiannual cycle, different stocks are included in each yearly working group report. Generally, stocks cover one or several geographical sub-areas (GSAs).

Catch information

Catch information for the Mediterranean and Black Seas is extracted from the FAO regional workspace including on 'GFCM (Mediterranean and Black Sea) capture production'. Catch information is available by fishing area (FAO division). Total catch for the assessed stocks for the Mediterranean and Black Seas is calculated by selecting catches for the species for which STECF provides F/FMSY information, where the following assumptions are made:

  • As the multiple fishing areas of the Mediterranean Sea do not directly coincide with the GSAs, overall catch is used for the Mediterranean Sea for the assessed species.
  • Catches are extracted by linking the common name in the stock description with the species name in the catch data set.

The total catch for non-assessed stocks in the Mediterranean and Black Seas is calculated by subtracting the calculated total catch for assessed stocks from the total catches for these two regions. 

GES

The status of the commercial species per MSFD (sub-)region is assessed based on all stocks for which the required information on F and FMSY is available. For each region, the proportion of stocks that fulfils the F criteria for GES is calculated.

Methodology for gap filling

Not applicable

Methodology references

 

Data specifications

EEA data references

  • No datasets have been specified here.

External data references

Data sources in latest figures

 

Uncertainties

Methodology uncertainty

MSFD (sub-)regions

The matching of catch areas and stocks to the MSFD regions/sub-regions is not final and may change following further consultations.

Data sets uncertainty

Catch and stock assessment data

Depending on the year selected, the suite of assessed stocks may change (notably in the Mediterranean and Black Seas because here they do not conduct annual stock assessments for all stocks simultaneously), and for the same stock indicator values may change.

Rationale uncertainty

Status of commercial species

The status of commercial species is expressed as the proportion of stocks that fulfils one or more of the GES criteria, as this is the most straightforward method since it does not require any additional information. However, the status can also be expressed as the proportion of catches or the proportion of biomass, depending on data availability. Each method is likely to give different results. The pros and cons of each method should be considered and a best method should be agreed upon.

Similarly, the status of European marine fish and shellfish over time is shown for both GES criteria considered as the annual mean ratio indicator/GES threshold, while, alternatively, the annual mean ratio deviation of the indicator from the GES threshold relative to that threshold can be calculated. This is also likely to give different values but is unlikely to give rise to different conclusions. The pros and cons of each method should be considered and a best method should be agreed upon.

For compliance with the status assessments in relation to the CFP, the same stocks for the Mediterranean Sea as those used by the STECF are adopted. This implies that, in contrast to the previous assessment, only stocks assessed by the GFCM (hence not the International Commission for the Conservation of Atlantic Tunas (ICCAT)) are used for this assessment.

Further work

Short term work

Work specified here requires to be completed within 1 year from now.

Long term work

Work specified here will require more than 1 year (from now) to be completed.

General metadata

Responsibility and ownership

EEA Contact Info

Ana Tejedor

Ownership

European Environment Agency (EEA)

Identification

Indicator code
CSI 032
MAR 007
Specification
Version id: 4

Frequency of updates

Updates are scheduled once per year

Classification

DPSIR: State
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
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