Mediterranean Sea: A Failure of the European Fisheries Management System

North East Atlantic and the Mediterranean Sea fisheries are governed by the European Common Fisheries Policy (CFP). Despite the fact that both areas are managed under the same broad fishery management system, a large discrepancy in management performance occurs, with recent considerable improvement of stock status witnessed in the North East Atlantic and a rapidly deteriorating situation in the Mediterranean Sea. The control of fishing effort combined with specific technical measures, such as gear regulation, establishment of a minimum conservation reference size, and selective closure of areas and seasons, is the main management strategy adopted by Mediterranean Sea EU countries. On the other hand TAC (Total Allowable Catches) is the major regulatory mechanisms in the North East Atlantic. Here, we analyzed all available stock assessment and effort data for the most important commercial species and fleets in the Mediterranean Sea since 2003. The analysis shows that there is no apparent relationship between nominal effort and fishing mortality for all species. Fishing mortality has remained stable during the last decade, for most species, with a significant decline observed only for red mullet and giant red shrimp but an increase for sardine stocks. Also, current F is larger or much larger than F_MSY for all species. Despite catch advice are produced by STECF each year, the realized catches have usually been much larger than the scientific advice. A recent analysis argued that this dichotomy might be due to several factors, such as the better enforcement of monitoring control and surveillance in North East Atlantic, the more complex socio-economic situation and the less effective management governance in the Mediterranean Sea. Here we argue instead that major reasons for the alarming situation of Mediterranean Sea stocks can be found in the ineffectiveness of the current effort system to control F, the continuous non-adherence to the scientific advice and inadequacies of existing national management plans as a key management measure. It is therefore undoubted that alternatives management measures as a TAC based system are necessary if Europe is willing to achieve the objectives of the CFP before 2020 in the Mediterranean Sea.

Introduction

In 2002, the World Summit on Sustainable Development (WSSD; United nations, 2002) established the deadline for the recovery of world's depleted fish stocks to biomass levels that can produce the maximum sustainable yield (B_MSY) no later than 2015. The Common Fisheries Policy (CFP) fixes the rules and directions for a sustainable exploitation of marine resources exploited by European fishing fleets (Regulation (EU) No 1380/2013; EU, 2013). The main objective contained in Article 2(2) of the new CFP is the restoration and/or maintenance of populations of harvested species above B_MSY levels. This approach would ensure that fisheries are sustainable and profitable in the long term, and that comply with European Union (EU) environmental legislation, as well as with international law principles. All future fisheries measures, and all actions undertaken by EU and Member State institutions, must serve to deliver these objectives, complying with the requirement to set fishing levels below F_MSY [i.e., fishing mortality (F) that delivers B_MSY] and aimed at achieving stock levels above B_MSY. Any measures that take a different approach will be in breach of the CFP, i.e., unlawful.

The first time that the CFP has been enforced was in the 1970s and has been successively updated in 2002 and recently in 2014. The CFP keystone is the sustainable exploitation of marine resources both in environmental and socio-economic terms directing toward a dynamic fishing industry and ensuring a fair standard of living for fishing communities. The current CFP specifies that between 2015 and 2020 exploitation is carried out according MSY principles and is able to maintain fish stocks in the long term. In the case of the impact of fishing on the marine environment is not fully comprehended, the CFP adopts a precautionary approach and seeks for more selective fisheries with a complete ban of discards. Similarly, also the Marine Strategy Framework Directive (MSFD; EU-COM, 2008, 2010) requires EU Member States to take measures to achieve Good Environmental Status (GES) of all European marine waters by 2020.

After 8 years from the adoption of WSSD and the enforcement of MSFD with the definition of GES and targets in each Member State (MS), and the concurrent application of the CFP, Europe has made great progress toward MSY for stocks inhabiting the North East Atlantic (e.g., Cardinale, 2011; Cardinale et al., 2012; Fernandes and Cook, 2013) but it is still far from achieving its objectives for the Mediterranean Sea marine resources (e.g., Colloca et al., 2013; Vasilakopoulos et al., 2014). Notwithstanding the enforcement of the EU Data Collection Regulation (EU, 2000) in the early 2000s by all EU MSs, and the rapid increase in the number of assessed stocks by the General Fisheries Commission for the Mediterranean (GFCM) and the European Scientific, Technical and Economic Committee for Fisheries (STECF), Mediterranean Sea marine resources are still exploited above the levels that deliver the maximum sustainable yield and no signs of recovery are evident (Vasilakopoulos et al., 2014). Particularly, in the Mediterranean Sea, the achievements of WSSD targets is at risk to be further delayed by the management systems currently enforced at the national and EU level.

From the management perspective, Mediterranean Sea countries are limited mainly to control fishing effort and fishing capacity together with specific technical measures, such as gear regulation (mainly mesh size and net configuration, in particular for purse seine), establishment of a minimum conservation reference size, and closures of areas and seasons for fishing. Moreover, the Article 19 of Council Regulation (EU, 2006; hereafter referred to as “the Mediterranean Regulation”) foreseen that management plans within their territorial waters are adopted for trawling and other fishing activities. In this context, it is important to notice that spatial and temporal closures apply mainly to trawls, which are prohibited within 3 nautical miles from the coast or within the 50 m isobath, where this is closer to the coast. Also, temporal closures regard bottom and mid-water trawl nets are mainly enforced for 30–45 days during summer (Demestre et al., 2008). A second set of management measures in the Mediterranean Sea incorporate the establishment of permanent marine protected areas. However, the extension of MPA is still rather limited in the Mediterranean Sea, covering around 9.5% of the EU water within 200 nm and being mostly located in the Western Mediterranean (http://www.eea.europa.eu/data-and-maps/figures/regional-seas-surrounding-europe-and-2).

Conservation reference points are established in national management plans in order to recover or maintain the stock within safe biological limits ensuring the sustainable exploitation of stocks and that impact of fishing activities on marine eco-systems is kept at sustainable levels. An important feature of these plans is that they should be solely adopted within the territorial waters of each MS, and thus do not consider the transboundary dimension of most of the stocks exploited in the Mediterranean Sea.

Here, we collated and analyzed all available information on Mediterranean Sea stocks. We analyzed the current stock status of Mediterranean Sea marine resources and compared it to the F_MSY target. We also explored the temporal trends in F to determine if the status of stock is improving or worsening. Further, we analyzed the relationship between F and nominal fishing effort for stocks fished by EU MSs only.

Materials and Methods

We collated information on the Mediterranean fish stocks from relevant reports of STECF (https://stecf.jrc.ec.europa.eu/reports/medbs) and GFCM SAC (http://www.fao.org/gfcm/reports/statutory-meetings/en/), published over the period 2007–2015. These reports were used to extract estimates of fishing mortality (F), fishing mortality which corresponds to MSY (F_MSY), SSB (Stock spawning biomass), recruitment, catches, and advised catches for each stock. Collated data were stored in a database which contains all available information on the status of 142 stocks (as combination of species and GSAs (i.e., Geographical Sub-Areas) derived from assessments conducted between 2007 and 2014 (Table 1, Figure 1). In total, more than 500 stock assessments results were collated, which cover 26 different species and 27 GSAs or combination of GSAs. However, not all stocks resulted in an analytical stock assessment. Also, data on fishing effort by fisheries in terms of Kw/Days at Sea (i.e., nominal effort) and Gross tonnage/Days at sea were extracted and collated for each GSA and fisheries. This represents the most complete database of stock assessment results for the Mediterranean region available to date.

TABLE 1

Table 1. List of species and stocks (by GSA or combination of GSAs) collated in this study with the associated reference where the stock assessment has been conducted.

FIGURE 1

Figure 1. Map of the GFCM Geographical Sub-Areas (GSAs) established in the resolution GFCM/33/2009/2 (GFCM, 2009d).

For the exploration of temporal trends in F and effort, we selected the main species and fisheries operating in the Mediterranean Sea. The species selected were European hake, red mullet, deep-water rose shrimp, Norway lobster, giant red shrimp, blue and red shrimp, European anchovy, and sardine. The landings of these species in 2014 constituted approximately 55% of the total landings in the European GSAs of Mediterranean Sea and they are considered as the target species in all GSAs (2015-Economic Data Call; Table 2). The fisheries selected were demersal trawl operating on the shelf (hereafter defined as demersal coastal trawl), demersal trawl operating in the deep (hereafter defined as demersal deep trawl), purse seine, pelagic trawls and net, lines, and traps combined (hereafter defined as passive gears) (Table 3). The gears included in each of the fisheries selected are summarized in Table 3. Here, we used both nominal effort in Kw/Days at sea and Gross Tonnage/Days at sea as a measure of effort in the analysis.

TABLE 2

Table 2. Landings by species, GSA and gear in 2014 for species included in the GAM models (source: 2015 Economic data call).

TABLE 3

Table 3. Combination of species assigned to each gear and fisheries analyzed in the present study.

Statistical Analysis

Generalized Additive Models (GAMs; Hastie and Tibshirani, 1990) were used to account for the unbalanced design in the data available between years and GSAs. The model non-linearity, a common characteristic of biological data, is one of the main benefits that GAMs can handle. Fishing mortality was scaled by the level of F_MSY in order to make the different stocks comparable in the analysis. A normal distribution (Minami et al., 2007) to model the ration F/F_MSY has been used.

For each species a GAM model was fitted:

${\text{F/F}}_{\text{MSY}}~\text{ s}(\text{year})+\text{s}(\text{effort})+(\text{GSA})$

For hake, demersal coastal trawl, mixed trawl and net, and lines effort were included. For red mullet, only demersal coastal trawl effort was considered. For deepwater pink shrimp and Norway lobster, mixed and deep demersal trawl effort was used while for anchovy and sardine, purse seines and pelagic trawlers effort was used (Table 3). The combination among species and gear/fisheries have been made in accordance with the last STECF available assessments (STECF, 2015a,b, 2016).

The isotropic smooth (i.e., thin plate regression spline) function (Wood, 2004) has been used to model Year and effort while GSA was modeled as a factor. The maximum number of knots was limited for the smooth term of effort (k ≤ 3) and year (k ≤ 7), in order to simplify the output interpretation. For each species model, two different link functions were tested, a log link which assumes constant variance and a identify link which assumes constant coefficient of variation and hence a variance proportional to the square of the mean. The best model was chosen using the AIC (Akaike Information Criteria) (Akaike, 1974). Effort data was available only from 2002 and thus only these years (i.e., 2002–2014) were included in the analysis.

The assumptions of variance homoscedasticity and normal distribution of data have been explored throughout the analysis of the residuals. Similarly, the residuals were employed to inspect analyses the departure from the model assumptions or other anomalies in the data or in the model fit using graphical methods (Cleveland, 1993).

Comparison between Forecast Catches and Real Catches

In most of the stock assessment carried out in the framework of GFCM and STECF short-term forecasts have been conducted for 2 or 3 years after the reference year of the assessment. The short-term predictions were usually implemented in R (https://www.r-project.org/) using the FLR libraries and based in most of the cases on the results of the Extended Survivor Analyses (XSA, Darby and Flatman, 1994) or other assessment models. Several scenarios of F were tested as well as the F which is in accordance with the F_MSY. The method employed allowed to estimate the catches relative to the F reference points assuming a constant recruitment in the following 2 years equal to the geometric mean of the previous 3 years. Such reference catches have been then compared with the real catches for each stock analyzed.

Results

There is no difference in the model results when using Kw/Days at sea or Gross Tonnage/Days at sea and thus only results for Kw/Days at sea were presented here. This was expected as Kw/Days at sea and Gross Tonnage/Days at sea are highly significantly correlated for all GSA and fisheries selected here (r² = 0.91; p < 0.05).

Table 4 summarize the detailed results for all GAMs fitted. A total of eight GAMs were fitted. The significant effects for all models fitted are presented in Figure 2. Model assumptions of normality and homogeneity of variance have been respected, as showed by the analysis of the residuals (data not shown).

TABLE 4

Table 4. Results of the GAMs for each species.

FIGURE 2

Figure 2. Effect of the predictors (with the 95% confidence intervals) on the ratio between F/F_MSY for each model species. Only significant predictors were shown. For model details see Material and methods.

Generally all GAMs explained a rather large part of the deviance (76.3–95.1%) with an r² which ranged between 0.70 and 0.93. The log link was selected as the best model based on the AIC for hake, red mullet, Norway lobster, and sardine. The identity link resulted in the best model for deep water pink shrimp, giant red shrimp, blue and red shrimp, and sardine (Table 4).

Concerning the effect of the different predictors included in the models, the results of the GAM analysis showed that effort was not significantly related to F/F_MSY in any of the model fitted except for deep water pink shrimp (Figure 2). However, the shape of the effect of effort on F/F_MSY for deep water pink shrimp is contradictory to the expectations (i.e., decreasing F/F_MSY with increasing effort) and thus it was considered to be spurious. On the other hand, the effect of GSA was significant for all models. The year effect was significant only for red mullet, giant red shrimp (decreasing trend in F/F_MSY over time) and sardine (increasing trend of F/F_MSY over time).

The average ratio F/F_MSY is larger than 1 for all species, ranging from 1.7 to 8.1 (Giant red shrimp and hake, respectively; Table 4). Even for red mullet and giant red shrimp, for which the ratio F/F_MSY has significantly declined over time, the value of the last year (i.e., 2014) is still above 1 (2.5 and 1.1, for red mullet and giant red shrimp, respectively).

In Table 5 are reported the comparisons between the forecasted yearly catches in accordance with F_MSY and the realized catches estimated for the target stocks previously analyzed. In almost all cases realized catches have been much larger than the forecasted ones, with an average catch over the analyzed time period (i.e., 2010–2014) being around 178% larger than the scientific advice.

TABLE 5

Table 5. Difference (in %) between the scientific catch advice and the realized catches for each year and stock for which a short term forecast was carried out.

Discussion

In recent years European fisheries managers have witnessed the success of the European CFP in the north (i.e., North East Atlantic, Cardinale et al., 2012; Fernandes and Cook, 2013) and at the same time, its failure in the south (i.e., Mediterranean Sea, Colloca et al., 2013; Vasilakopoulos et al., 2014). Thus, despite the fact that both areas are managed under the same broad fishery policy (i.e., European CFP), a large discrepancy in management performance still occur between the North East Atlantic and the Mediterranean Sea.

The fishing mortality exerted on the North East Atlantic has shown a rapid and general decline during the last 15 years and even the spawning stock biomass has started to show clear signs of increasing for several stocks in the North East Atlantic area (www.ices.dk). On the other hand, Mediterranean stocks have largely declined in the last 15 years and their exploitation level has raised or remained above the F_MSY level during the same period of time (Vasilakopoulos et al., 2014; this paper). Here we showed that up to 2014, the average exploitation rate for the main demersal and small pelagic stocks of the Mediterranean Sea is around three times the estimated level of F_MSY, with a general similar pattern across species and area, which confirms analyses recently conducted (STECF, 2015c). Moreover, as we have mostly only a snapshot of the last decade for Mediterranean stocks (i.e., generally from the beginning of the 2000s to today), and, as F has been estimated to be very high since the beginning of the time series (Colloca et al., 2013; Vasilakopoulos et al., 2014), the decline in stock biomass might have started much before and being more pronounced than described by current assessment models. This has been demonstrated by those assessments with a longer time series, as small pelagics in the Adriatic Sea (time series: 1975–2014; GFCM, 2015b) and common sole in the Northern Adriatic Sea (time series: 1970–2014; GFCM, 2015a; STECF, 2016).

The CFP obviously applies to the Mediterranean Sea as well, although it has been argued that, as several Mediterranean stocks are shared with non EU countries on the southern part of the basin, the unsuccessful management of the CFP could be attributed to the fact that Europe has no jurisdiction on these stocks. However, there are several Mediterranean stocks that are solely distributed within EU territorial waters (i.e., several Spanish, France and Italian stocks located in GSAs 4–11) and for which therefore the CFP is the primary (and only) management instrument for assuring their long term sustainable exploitation. Here we showed that the average exploitation rate for the main demersal and small pelagic stocks of the Mediterranean Sea exploited solely or mostly by European fleets is around three times the estimated level of F_MSY, with a general similar pattern across species and areas. This pattern has been observed for more than a decade and there are no signs of a decline in the exploitation in the latest years.

A striking difference in the management of marine fish stocks between North East Atlantic and the Mediterranean Sea is that Mediterranean Sea is primarily managed by effort control while North East Atlantic stocks management has been based primarily on TACs, which are regularly provided by ICES to the EC. Recent trends in decision making indicate that scientific advice in the North East Atlantic has been more closely followed in later years, with the proportion of EU TACs set above scientific advice that has declined from 33% in 2001 to only 7% in 2015 (Carpenter et al., 2016) while no such trend exists for Mediterranean stocks. In fact, notwithstanding that the scientific advice (i.e., TAC advice) has been provided by STECF since 2008, it has rarely been followed or implemented, with realized catches being much larger than the scientific advice (178%; this paper). Even the realized reductions in effort (e.g., a minimum reduction of bottom-trawling fishing effort in the Mediterranean is foreseen by GFCM resolution RES-GFCM/33/2009/1, GFCM, 2009c) have always been much smaller than what deemed necessary by the scientific advice (Colloca et al., 2013). Moreover, another key difference between North East Atlantic and Mediterranean is the low level of compliance and enforcement in the Mediterranean compared to the North East Atlantic (Vasilakopoulos et al., 2014). This is an important element of any fisheries management system, which has surely contributed to the current situation of Mediterranean Sea stocks.

One of the most important results from our analysis is that effort reduction is not accompanied by a concomitant reduction in fishing mortality for all species. Here, we have shown that F and effort are decoupled as effort reductions do not corresponds to reduction in F. Our analysis does not clearly indicate why this has been the case, but the most likely explanation is that nominal effort is not an actual measure of the real effort of the fleet, especially in the case of passive gears (Ribeiro et al., 2015, 2016). It is important to notice that the measures of effort used here are adequate for purse seines and trawling, but less for local, small scale fisheries, which with the same gross tonnage or kw per hour can deploy very different amount of fishing efforts in terms of number or length of gears, and this might risk to invalidate the relationship between F and effort. However, for the species analyzed here, most of the catches are taken by the trawlers and purse seines. For example, small scale fisheries are responsible of around 1% of the catches of small pelagics, <1% of the catches of blue and red shrimp, giant red shrimp and deep-water rose shrimp, and around 5% of those of Norway lobster. Also at GSA level, catches of small pelagics, Norway lobster, and shrimps are mainly taken by trawlers and purse seines. Only for red mullet and hake, the small scale fisheries take a significant but still minor part of the catches, 15 and 23% respectively, which can be even larger in some GSA (Table 2). Thus, we consider that the results of our analysis are robust regard to the way the effort has been measured here. Nevertheless, whatever is the mechanism behind the lack of a relationship between F and effort in the Mediterranean Sea, the results shown here demonstrated that putative management based mainly on reduction in nominal effort has failed in the Mediterranean Sea and it is most likely that it will most likely fail also in the near future. It is therefore undoubted that alternatives management measures as a TAC based system are necessary if Europe is willing to achieve the objectives of the CFP before 2020 in the Mediterranean Sea.

Another important measure for the management of the Mediterranean Sea stocks within the Mediterranean regulation is the implementation of national MP. Such MPs are allowed by the current Mediterranean Regulation and they are developed at the level of fisheries and/or gear types within national borders. Here, we argue that allowing national management is a clear weakness of the current Mediterranean Regulation as such plans are a very inefficient management measure since they disregard the real geographical distribution of the stocks and fisheries exploiting them. As a matter of fact, most of the stocks are exploited by multiple fisheries and often by different member states. Therefore, it is considered that for stocks shared both in terms of different countries and fleets exploiting them, a fishery management plan needs to include all fleets and countries exploiting the stock (STECF, 2012e). This is likely the reason why management plans in the North East Atlantic have been progressively successful in recent years (STECF, 2014b) while it has not been the case in the Mediterranean Sea (e.g., the multiannual MP for small pelagic in the Adriatic, GFCM/37/2013/1; GFCM, 2013, 2016) and it also clearly highlight another crucial weakness of the current Mediterranean regulation.

Within the framework of an Ecosystem Approach to Fisheries Management, a properly designed and integrated network of different types of MPA could potentially help in achieving a better exploitation pattern and the MSY sustainability target. However, the extension of MPA in the Mediterranean Sea is still rather limited (http://www.eea.europa.eu/data-and-maps/figures/regional-seas-surrounding-europe-and-2) and thus MPA are likely to contribute only little to the current management of Mediterranean stocks. It is also unquestionable that the complexity of the Mediterranean fisheries, with a large number of small vessels operating at a small spatial scale in very local fisheries, and the diverse cultural, social and economic characteristics of the countries sharing the resources pose significant challenges to sustainable management of Mediterranean marine resources (Piroddi et al., 2015). However, here we shown that even stocks mainly caught by trawlers and purse seines within EU waters, are fished not in accordance with the CFP MSY target and that management of these stocks is ineffective to control their level of exploitation. Moreover, these stocks have a central role in management resolutions as they are the key species of future Mediterranean management plans.

Vasilakopoulos et al. (2014) argued that the difference in fisheries management performances between the Northern and the Southern part of Europe pattern might be explained not only by the more sophisticated management regime and better compliance and enforcement of the North East Atlantic, but also by the socio-economic complexity and less effective governance system in the southern Europe (Smith and Garcia, 2014). Here, we showed instead that major reasons for the alarming situation of Mediterranean Sea stocks can be found in the ineffectiveness of the putative effort reductions to control fishing mortalities, the continuous non-adherence to the scientific advice, and the existence of ineffective national management plans as a primary management measure. The European CFP has failed to achieve MSY before 2015 for the Mediterranean Sea and will face large difficulties to reach MSY and MSFD targets before 2020 under the current management regime.

Author Contributions

All authors listed, have made substantial, direct and intellectual contribution to the work, and approved it for publication.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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