Status of marine fish and shellfish stocks in European seas

Persistent overfishing threatens Europe’s marine ecosystems, food security and biodiversity. The EU takes an integrated approach to restore and maintain healthy fish populations while ensuring their sustainable use. Management efforts have led to some stock recovery, mainly in the North-East Atlantic Ocean, while progress has been slower in other regions. The situation remains critical in the Mediterranean and Black seas, where fishing mortality rates are double the sustainable levels and 73% of the assessed stocks are overfished. EU objectives to restore healthy fish and shellfish stocks have not been met across Europe's seas. Further concerted actions are urgently needed to achieve sustainable fisheries.

State of European commercial fish and shellfish stocks (for which stock assessments were conducted between 2019-2022), in relation to the Good Environmental Status criteria for fishing mortality and reproductive capacity per marine region

The EU Marine Strategy Framework Directive (MSFD) aims to achieve good environmental status (GES) for all marine waters across Europe, including by restoring and maintaining healthy commercial fish and shellfish stocks. It builds on existing EU legislation and extends the coverage to specific elements of the marine environment not addressed in other policies.

Key policies include the EU Common Fisheries Policy (CFP), which aims to ensure that fisheries are sustainable and do not damage the marine environment, thus contributing to GES. In turn, these policies support the ambitions of the European Green Deal which aims to protect biodiversity and ensure sustainable fisheries sectors through the Action plan: Protecting and restoring marine ecosystems for sustainable and resilient fisheries within the EU Biodiversity Strategy 2030, the Zero Pollution Action Plan and Farm to Fork strategy.

Three criteria are used to assess GES for commercial fish and shellfish stocks under the MSFD, based on:

level of exploitation, measured by fishing mortality (F);
reproductive capacity, assessed by spawning stock biomass (SSB);
age and size distribution.

This indicator looks at progress made towards achieving GES by tracking fishing mortality and reproductive capacity. Currently, it is not possible to assess GES based on criterion 3 due to the lack of an established indicator and agreed threshold values.

Strong regional differences exist. In the North-East Atlantic Ocean and Baltic Sea, approximately 62% of the assessed stocks meet at least one of the two GES criteria, while 29% are in good state based on both criteria. In the Mediterranean and Black seas, the situation is more critical where only 26% of assessed stocks are in good state based on at least one criterion: three out of 97 stocks based on two criteria (all of them in the Mediterranean Sea), and 22 based on one criterion (among which only one in the Black Sea) (Figure 1).

Accurate assessments of the state of the marine environment are vital for monitoring progress towards meeting policy objectives. Assessing more stocks to better inform GES assessments will be important, along with developing metrics that allow accurate assessments of the age and size distribution of fish populations. In 2021, 72% of landings from Europe’s seas were from stocks for which at least one GES criterion could be assessed. Again, there were distinct regional differences. Assessments of at least one criterion were possible for 76% of landings from the North-East Atlantic Ocean and Baltic Sea, but only for 36% of landings from the Mediterranean and Black seas.

State of assessed commercial fish and shellfish stocks in relation to the good environmental status criteria for fishing mortality and reproductive capacity in marine regions

For North-East Atlantic Ocean and Baltic Sea stocks, fishing mortality levels increased from near sustainable levels (i.e., where F/F_MSY≤1) in the 1950s to more than double (i.e., F/F_MSY>2) by the 1980s and 1990s. This led to a decline in reproductive capacity until the early 2000s, putting it at risk of becoming impaired, i.e. depleted to a point where it is no longer able to sustain healthy population levels to support fisheries. Trends suggest that targeted measures, such as Total Allowable Catches (TACs), have since fostered improvements.

Fishing mortality rates have declined towards sustainable levels on average and reproductive capacity shows signs of recovery; however, as indicated by the confidence limits, several stocks remain outside safe biological limits (Figure 2).

In contrast, there is no clear sign of improvement in the Mediterranean and Black seas, where management continues to be largely based on regulating fishing effort. Most stocks assessed continue to be fished at unsustainable levels and reproductive capacity has not improved from 2003. For these stocks, very few GES thresholds for reproductive capacity have been defined but it is likely that reproductive capacity was below a healthy level already in 2003 (Figure 2).

Overall, the MSFD and CFP targets to restore healthy fish and shellfish stocks have not been met across Europe's seas. Further collective action, better implementation and enforcement of EU policies are required to ensure the long-term health of fish stocks and the sustainability of the fisheries that depend on them.

Supporting information

Definition

The indicators track 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) from commercial fisheries in European seas per MSFD (sub-)region;

· 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.

Methodology

North-East Atlantic Ocean and Baltic Sea

For the North-East Atlantic Ocean and Baltic Sea, the indicator is calculated using assessments from the ICES stock database from 2019-2022. The ICES stock assessment database consists of 199 stock assessments, 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

Currently, 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 (fishing mortality) and SSB (spawning stock biomass), in combination with MSY-based reference values, are the most appropriate metrics for these two criteria. The metrics used for F and SSB may differ between stocks. Not all stocks can be assessed for both metrics. ICES has developed methods for providing status in relation to MSY goals for fishing pressure and stock size using data-limited methods (ICES, 2022). This has expanded the number of stocks for which assessments of the two criteria have been made.

Total landings in MSFD (sub-)regions

Stocks are assigned to an MSFD ecoregion based on the ICES subareas and divisions. Under the MSFD, individual stocks may be considered in more than one ecoregion. However, for this analysis stocks are assigned to one ecoregion, considered to be most important to the stock and fishery. ICES is presently developing a system of assigning stocks to appropriate ecoregions based on distribution and migration patterns as well as location of landings.

Total landings data are extracted from the ICES Official Nominal Catches data set (note: in FAO terminology, ‘nominal catches’ refer to ‘landings’) and are assigned to the different MSFD regions based on area. The total landings for non-assessed stocks by ecoregion is calculated by subtracting total stock landings by ecoregion from the total landings by ecoregion.

Good status

The status of commercial species per MSFD ecoregion is assessed based on all stocks for which the required information on F and/or SSB is available, or (for some stocks assessed by ICES) proxy methods exist to determine the status in relation to MSY targets.

For each region, the proportion of stocks that fulfil both (F and SSB), one (only F or only SSB if both criteria are known) or none (F or SSB if only a single criterion is known) of the MSFD criteria for GES is calculated. Thus, the five 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.

· None: stocks for which F and SSB information is available and do not fulfil the MSFD criterion for any of the two, and stocks for which only F or only SSB information is available and do not fulfil the GES criterion.

Mediterranean and Black seas

Proportion of assessed stocks

In the Mediterranean Sea and Black Sea, stocks are mostly defined by management area because of a lack of biological knowledge. As such, they are referred to as ‘assessment units’ in this report to distinguish them from biologically defined stocks and no total number of stocks per region is reported. Assessment units in these regions are assessed based on assessments available through the Scientific, Technical and Economic Committee for fisheries (STECF), and through the GFCM, performed between 2021 and 2022. As assessments are carried out in a multiannual cycle, different assessment units are included in each annual working group report.

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. Not all stocks can be assessed for both metrics.

Total landings in MSFD (sub-)regions

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

· As the multiple FAO fishing areas of the Mediterranean Sea do not directly coincide with the GSAs, overall landings is used for the Mediterranean Sea for the assessed species.

· Landings are extracted by linking the common name in the stock description with the species name in the landings data set.

The total landings for non-assessed units in the Mediterranean and Black seas is calculated by subtracting the calculated total landings for assessed stocks from the total landings for these two regions.

Good status

As for the North-East Atlantic Ocean and Baltic Sea.

Policy/environmental relevance

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. To achieve sustainability, the levels of exploitation and reproductive capacity need to be analysed to assess the status of marine fish and shellfish in Europe.

Through the implementation of the CFP and the MSFD, EU Member States are committed to maintaining fish populations at biomass levels above those required to produce the maximum sustainable yield (MSY), by exploiting the stocks at appropriate fishing mortality rates in 2015 where possible, and by 2020 for all stocks; an objective that has not yet been reached.

Descriptor 3 (D3) of the MSFD also sets out that populations of commercial fish and shellfish have full reproductive capacity in order to maintain stock biomass and the proportion of older and larger fish/shellfish should be maintained (or increased) being an indicator of a healthy stock.

Good Environmental Status (GES) is achieved for a particular stock only if all of the three attributes are fulfilled. Currently, only two criteria can be used for assessing GES. Moreover, 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:

· the proportion of the total catch in the MSFD (sub-)regions of Europe covered by the quantitative stock assessments conducted by the ICES and the General Fisheries Commission for the Mediterranean (GFCM);

· the proportion of the total number of stocks in the MSFD (sub-)regions of Europe covered by quantitative stock assessments conducted by the ICES and the GFCM;

· an overview of the status of assessed fish stocks per MSFD (sub-)region and its trend over time, with GES being based on two criteria being met:

- a sustainable level of exploitation (assessed by F);

- reproductive capacity not being compromised (assessed by SSB).

Accuracy and uncertainties

Methodology uncertainty

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.

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.

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 only stocks assessed by the GFCM (hence not the International Commission for the Conservation of Atlantic Tunas (ICCAT)) are used for this assessment.

Datasets uncertainty

Catch and stock assessment data: depending on the year selected, the suite of assessed stocks may change (in the Mediterranean and Black seas because they do not conduct annual stock assessments for all stocks simultaneously; and in the ICES areas many stocks are assessed only every two or more years). This may lead to indicator values changing simply because different stocks are considered each year. Therefore, the analyses presented here use latest assessment for each stock from the last five years (under the assumption that the most recent assessment is indicative of GES status until the next assessment is conducted).

Geographical comparability

Comparability is assured in each regional seas while comparability between regions is not always possible due to lack of thresholds for reproductive capacity. Very few GES thresholds for reproductive capacity have been defined for the Mediterranean and Black Sea.

Reproductive capacity between different regions (North-East Atlantic Ocean and Baltic Sea vs Mediterranean and Black seas) have different approaches to calculating threshold values in stock assessments.

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

Comparability over time

Data comparability depend on the number of stocks, data are mainly comparable after 2000. Data are comparable in the time frame of this indicator 2019-2022.

Data sources and providers

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Status of marine fish and shellfish stocks in European seas

Figure 1. State of European commercial fish and shellfish stocks (for which stock assessments were conducted between 2019-2022), in relation to the Good Environmental Status criteria for fishing mortality and reproductive capacity per marine region

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Figure 2. State of assessed commercial fish and shellfish stocks in relation to the good environmental status criteria for fishing mortality and reproductive capacity in marine regions