European Common Fisheries Policy Research Articles

An integrated end-to-end deep neural network for automated detection of discarded fish species and their weight estimation

Abstract Sustainable management of aquatic resources requires efficient acquisition and processing of vast amounts of information to check the compliance of fishing activities with the regulations. Recent implementation of the European Common Fisheries Policy Landing Obligation implies the declaration of all listed species and sizes at the harbour. To comply with such regulation, fishers need to collect and store all discards onboard the vessel, which results in additional processing time, labour demands, and costs. In this study, we presented a system that allowed image-based documentation of discards on the conveyor belt. We presented a novel integrated end-to-end simultaneous detection and weight prediction pipeline based on the state-of-the-art deep convolutional neural network. The performance of the network was evaluated per species and under different occlusion levels. The resulting model was able to detect discards with a macro F1-score of $94.10\%$ and a weighted F1-score of $93.88\%$. Weight of the fish could be predicted with mean absolute error, mean absolute percentage error, and root squared error of 29.74 (g), $23.78\%$, and 44.69 (g), respectively. Additionally, we presented a new dataset containing images of fish, which, unlike common object detection datasets, also contains weight measurements and occlusion level per individual fish.

Guarding net effects on landings and discards in Mediterranean trammel net fishery: Case analysis of Egadi Islands Marine Protected Area (Central Mediterranean Sea, Italy)

Discards remain among the main negative impacts of fishing activities, and their reductions are strengthened by the European Common Fisheries Policy (European Regulation 1380/2013). Trammel net fisheries appear more sustainable compared with other fishing techniques, especially from an ecological viewpoint. Despite this, reports show that trammel net fisheries deliver discard quantities between 10% and 43% of the total catch biomass. To supplement existing information, this current work attempts to address the discard reduction using guarding net in the small-scale fisheries of Egadi Islands MPA (Western Sicily, Central Mediterranean Sea). To assess the reduction of unwanted catches, 48 experimental fishing trials were conducted within a 6-month period. The experimental fishing trial employed a trammel net made up of 20 panels alternated with two different net configurations. The control panels (CN) held a large outer (180 mm) and small inner (31.25 mm) meshes. The test panels (GN) with guarding net constituted a three-mesh-high (50-mm mesh size) net placed between trammel net panels and a lead line. A total of 3,310 individuals belonging to 106 taxa and nine phyla were caught. Crustaceans were the most abundant unwanted catches in the control panels, whereas bioconstructions occurred in the guarding net panels. The discard ratios of CN and GN panels were statistically different (t-value = –2.55; p< 0.05). The analysis of catch per unit effort showed higher catches of CN panels for both commercial and discard fractions (p< 0.05). Moreover, the guarding net panels caught the main discarded species at 20% lower compared with the control. The overall value of the catch at the CN panels (€ 3,366.90) was higher than the total income (€ 2,043.70) generated using the GN panels, which suggests a significant commercial loss of 40% (p< 0.05).

Turbot Survivability, Catches and Gillnet-Caused Injuries. Scientific Support for the Exemption from the Landing Obligation in EU Black Sea Countries

The European Common Fisheries Policy aims to gradually eliminate discards in all European Union fisheries through the introduction of a landing obligation for all catches of species subject to catch limits (turbot and sprat for the Black Sea). In 2016, the Commission established a discard plan for turbot fisheries in the Black Sea, that provided for a survivability exemption of turbot caught with bottom-set gillnets, applied from 1 January 2017 until 31 December 2019. Subsequently, Romania and Bulgaria submitted an updated Joint Recommendation to the Commission, requesting the renewal of the discard plan and the survivability exemption based on the high survival rates of this species. The Scientific, Technical and Economic Committee for Fisheries (STECF) acknowledged the existence of data demonstrating the high survivability of turbot caught by vessels from non-EU countries using the same gears, however they requested that Member States concerned should submit additional data on survival estimates relating to the gillnet fishery for turbot. In this context, NIMRD “Grigore Antipa“ was commissioned by the Romanian National Agency for Fisheries and Aquaculture (NAFA) to perform a pilot study aiming at obtaining scientific evidence for the exemption of turbot from the landing obligation, carried-out during January-April 2022. Scientific fishing was performed in the Romanian marine area with specialized gears - turbot gillnets on board of NIMRD’s boat. The methodology consisted of launching the gillnets in established locations and recovering them after a soaking time depending on weather conditions. After each operation to recover the nets from the water, all turbot specimens caught were retained on board, parked in a fiber-reinforced polymer (FRP) container filled with seawater and equipped with an aeration system. The specimens were kept in the tank for 1 hour, during which time they were monitored from the point of view of their condition (dead, alive, injuries, other negative effects produced by the fishing gear). Subsequently, all turbot specimens declared viable were released back into the sea. The results indicate high survivability rates of turbot caught in gillnets (81.67%). Some injuries were reported in the dead specimens, probably caused by the mechanical action of the gear.

Economic and social impacts of the landing obligation of the European Common Fisheries Policy: A review

The European Union landing obligation (LO) entered fully into force in 2019, with the aim of reducing discards by inducing fishing gear selectivity improvements and fleets’ behaviour changes. However, to date there has been no synthesis review of the economic and social impacts of the LO. To cover this gap, the objective of this paper is to provide a summary of what the scientific literature concludes on the economic and social impact of the LO considering also the exemptions and management adaptations in force. Resultswe show that while the number of scientific studies related to the economic impact of the LO is high, almost all of them are related to the forecasted consequences of the LO rather than actual consequences. Only a few studies used quantitative social indicators to measure the impacts of the LO. Findings from the synthesis review also indicate that the scientific literature generally concludes that the short-term economic and social impacts of the LO are likely to be negative, because choke effects will occur and mitigation measures require time to deliver results, while long term effects are variable and will depend on the mitigation measure in place. However, these results assume there is full compliance by fishers with the LO, while the literature suggests this is not the case. The review concludes that analysis of the economic and social impacts of the LO based on actual and not on forecasted results are scarce, which ultimately drives the policy recommendation of producing actual results and contrasting them with the forecasted results.The results serve as a decision-making framework to determine how critical factors of the LO may have the most economic and social effects, which are relevant in the context of the evaluation of the EU Common Fisheries Policy.

Discard survival of coastal elasmobranchs in a small-scale fishery using acoustic telemetry and recapture data

Discard reduction is a cornerstone of the European Common Fisheries Policy. The discard ban policy, which aims to reduce fisheries discards, is particularly challenging for small-scale fisheries. Demonstrating high survival rates of discarded individuals may provide flexibility to the application of the discard ban through the so-called survival exemption. Here we used acoustic telemetry and mark-recapture data to estimate discard survival of coastal elasmobranch species at multiple temporal scales. We focused on four species targeted by the small-scale fishery in Galicia (NW Spain), one of the most important fishing regions in Europe: Scyliorhinus canicula, Raja undulata, Rajaclavata and Rajabrachyura. The overall survival rate was 90% on the short term and 85.7% on the long term, but it varied among species. Survival rates of R. clavata and S. canicula on the short term were 70% and 100%, respectively, and 66.7% and 92.9% on the long term, respectively. All the individuals of R. brachyura and R. undulata survived on the long term. Our results are critical to support the application of survival exemption in small scale fisheries.

The carbon footprint of the hake supply chain in Spain: Accounting for fisheries, international transportation and domestic distribution

Climate change mitigation depends to a large extent on economic sectors modifying their production processes to significantly reduce their greenhouse gas emissions, particularly CO₂. However, greenhouse gas emission assessments are usually excluded from management of capture fisheries. Traditionally, hake ( Merluccius ssp. ) has been an important food for the population of Western Europe, and remains one of the most consumed fish in Spain's gastronomic culture. This paper reconstructs, for the first time, the hake seafood chain in Spain with the aim of estimating the carbon footprint of its extraction (fishing), transport and distribution. Our results show that total greenhouse gas emissions from the hake production and value chain in 2017 were 681 kt CO₂e, with an emission intensity of 4.42 kgCO₂e kg‾ 1 of whole fish. From these total emissions, those related to fishing operations represent 67% (456 kt CO₂e), with the remaining 33% (225 kt CO₂e) associated with transport (maritime, air or road). Air transport was the highest in terms of emission intensity per kilogram of hake transported (15.85 kgCO₂e kg‾ 1 ), and contributed to the largest share (72%) of transport emissions. Maritime transport presented the least emission intensity (0.33 kgCO₂e kg‾ 1 ) and predominated for hake caught outside the EU (e.g., Argentina, Namibia), offsetting the long distances the hake had to travel with greater transport efficiency. Our study highlights the importance of including greenhouse gas emissions analysis in the operationalization of the ecosystem-based fisheries management in the European Common Fisheries Policy as well as other regulations such as the Marine Strategy Framework Directive as a key tool for decision makers to appropriately address climate change impacts. The evidence provided by our study highlights the importance of finding a balance between healthy fish consumption patterns and their associated environmental impacts. • Only 8% of hake consumed in Spain comes from national fishing zones. • 47% of the hake caught by the Spanish fleet travels on average 12,000 km to Spain. • Fishing is the largest contributor to emissions from the hake supply chain in Spain. • The total GHG emissions of the hake supply chain in Spain account for 681 kt CO₂e.

Survival and Physiological Recovery after Capture by Hookline: The Case Study of the Blackspot Seabream (Pagellus bogaraveo)

Evaluating the survival of discarded species is gaining momentum after the new European Common Fisheries Policy (Article 15 of the European Regulation No. 1380/2013). This regulation introduced a discard ban, with an exemption for those species with demonstrated high survival rates after their capture and release. Candidate species should be evaluated for each fishing gear and geographical area. In this study, we assessed not only survival, but also physiological recovery rates of blackspot seabream (Pagellus bogaraveo) below commercial size captured with a hookline called “voracera” in the Strait of Gibraltar (SW Atlantic waters of Europe). Experiments onboard a commercial fishing vessel were paralleled with studies in controlled ground-based facilities, where the capture process was mimicked, and physiological recovery markers were described. Our results confirmed that hookline capture induced acute stress responses in the target species, such as changes in plasma cortisol, lactate, glucose, and osmolality. However, 90.6% of the blackspot seabreams below commercial size captured with this fishing gear managed to survive, and evidenced physiological recovery responses 5 h after capture, with complete homeostatic recovery occurring within the first 24 h. Based on this study, the European Commission approved an exemption from the discard (EU Commission Delegated Regulation 6794/2018). Thus, the robust methodology described herein can be an important tool to mitigate the problem of discards in Europe.

Exploring the impacts of fishing and environment on the Celtic Sea ecosystem since 1950

Analyzing the long-term changes in ecosystems and disentangling the influence of overfishing and environment require historical data integration. Fisheries-independent data are available only since the mid-1980s in the Celtic Sea and thus provide a short-term and truncated vision of fishing impacts. We conducted a catch-based study over the 1950–2015 period. We successively (i) reconstituted catch time-series, including unreported catch estimates, and studied them through a trophic-spectrum approach and ecosystem indicators based on trophic level, size and species diversity; (ii) estimated biomass trends of the main Celtic Sea target species from catch and effort time-series, using production models that detect potential shifts in productivity; and (iii) explored linkages between species productivity potential and both fishing and environment using long-term time-series of large-scale climatic indices, locally observed hydroclimatic variables and plankton data from the Continuous Plankton Recorder. Our results highlight that fishing has caused a drastic depletion of the main exploited species in the Celtic Sea since World War II. The biomass reduction of larger demersal species may reach more than 80 %; additionally, this depletion occurred earlier than previously thought and may have initiated a trophic cascade in the ecosystem. North Atlantic hydroclimatic variability affected species productivity, worsening the early stock depletion while potentially mitigating fishing impact in the 1990s. The common pattern in productivity changes among analyzed species highlights an abrupt transition whose timing matches that of the ecosystem shifts identified in several Atlantic ecosystems. Finally, we show that the recent fishing pressure reduction led by the European Common Fisheries Policy initiated a partial recovery of stocks and ecosystem status over the last decade.

An overview of the developments of the European Common Fisheries Policy regarding sustainable development and its regionalisation in Portugal and the Autonomous Regions

The European integration is not only a continental, but also a maritime integration, with the development of a maritime market including its maritime resources like fisheries. The development of the Common Fisheries Policy, in the European Union, has been marked by a few peculiar principles and tension among Member States. These developments have also been challenged by the developments of International Law, especially the Law of the Seas Convention, as well as the increasing attention given to a sustainable development and the need for maritime environmental development. The latest years have also been marked by a need for decentralization and regionalisation of the Common Fisheries Policy. The Iberian nations, especially Portugal, are a distinctive case with the rather difficult Common Fisheries Policy Integration. In spite of that, its singularity regarding its maritime presence and autonomic decentralized model give new potential for a new management and development of a decentralized Common Fisheries Policy, as well as a new possibility for sustainable development. In this paper, we analyse the development of the European Common Fisheries Policy as well as its role and interaction with International Law and the new concerns regarding sustainability of fishing stocks and its new management approach and needs for regionalisation. We also analyse its repercussions on Portugal and the potential offered by its own maritime and territorial peculiarities with its archipelagos and their own qualities and aptitude for a sustainable integration of the Common Fisheries Policy.

Taking the Pulse of Environmental and Fisheries Law: The Common Fisheries Policy, the Habitats Directive, and Brexit

Abstract There has long been a tension between environmental regulation and the European Common Fisheries Policy (CFP), which has been addressed over time through progressive reform of the CFP. It is now recognised that Member States may comply with their obligations under EU nature conservation law by taking unilateral non-discriminatory measures within their territorial seas to protect the marine environment from threats posed by fishing. Nevertheless, fundamental uncertainties remain when it comes to the application of these obligations to offshore waters. This article explores the options available to coastal states in this context and the weaknesses of the procedures introduced to the reformed CFP in 2013. It is argued that compliance with nature conservation law in the context of fisheries is not discretionary and that in the absence of measures agreed at the EU level, Member States must comply with their obligations under the Habitats Directive in their capacity as a flag state. Finally, the article addresses the implications of Brexit for the protection of European Marine Sites in UK waters, suggesting that Brexit offers opportunities to strengthen the protection of marine ecosystems by making future access arrangements for foreign fishing vessels conditional upon compliance with nature conservation laws.

Linking trawl fleet dynamics and the spatial distribution of exploited species can help to avoid unwanted catches: the case of the NW Mediterranean fishing grounds

With the full implementation of the landing obligation on 1 January 2019, In European waters it will become mandatory for the trawling fleet to land at port all catches of certain species because, according to Article 15 of the new European Common Fisheries Policy, the species subject to the minimum conservation reference size (MCRS) cannot be discarded. Additionally, since 2005, trawlers over 15 m in length are required to carry an onboard vessel monitoring system (VMS), which generates information on fleet dynamics. The objective of this work was to provide a tool for avoiding unwanted catches by integrating the catch study of trawlers operating in the port of Blanes together with VMS data. To achieve this objective, the catches of 40 hauls were monitored, sampled and analysed together with VMS data for the years 2012-2014 integrated in a geographical information system. The results show that specimens below the MCRS were often captured in crinoid aggregation habitats, bottoms with maërl and muddy bottoms that were identified as nursery habitats of commercial species, e.g. Merluccius merluccius, Pagellus spp. and Mullus spp. VMS data showed considerable fishing pressure on areas with maërl and muddy habitats during the recruitment periods of these and other commercially relevant species. Implementing spatial or seasonal closures in habitats where species regulated by the MCRS are subject to catches could be a useful tool for preventing unwanted catches.

Evolution of management in the Celtic Sea fishery: Economic effects on the Galician fleet

Characteristics and evolution of the Galician fishing fleet operating in the Celtic Sea are reviewed in a context of Spanish regulation and successive reforms of the European Common Fisheries Policy. This paper analyses the most significant aspects of fishing management that have affected this fleet's activity while linking the institutional framework to strategies and results of Galician fishing in these European waters and also identifying the fishery's greatest management challenges. Finally, we examine stakeholders' perceptions of the most relevant changes resulting from EU fishery reforms.

A bayesian estimation of the economic effects of the Common Fisheries Policy on the Galician fleet: A dynamic stochastic general equilibrium approach

What would have happened if a relatively looser fisheries policy had been implemented in the European Union (EU)? Using Bayesian methods a Dynamic Stochastic General Equilibrium (DSGE) model is estimated to assess the impact of the European Common Fisheries Policy (CFP) on the economic performance of a Galician (north-west of Spain) fleet highly dependant on the EU Atlantic southern stock of hake. Our counterfactual analysis shows that if a less effective CFP had been implemented during the period 1986–2012, fishing opportunities would have increased, leading to an increase in labour hours of 4.87%. However, this increase in fishing activity would have worsened the profitability of the fleet, dropping wages and rental price of capital by 6.79% and 0.88%, respectively. Welfare would also be negatively affected since, in addition to the increase in hours worked, consumption would have reduced by 0.59%.

Inter-species quota flexibility – Exploring a new management tool in European Common Fisheries Policy

Inter-species quota flexibility (IQF) is a new management tool made available to fishery managers in the reformed European Common Fisheries Policy (CFP) launched in 2013. IQF regulates a limited transfer between stock-specific total allowable catches (TAC), the main measure of stock conservation in CFP set in accordance with precautionary or, where possible, analytically estimated levels of maximum sustainable yield (MSY). IQF is intended to mitigate the various potential conflicts in the management of multi-species fisheries resulting from stricter catch limitations, which, in turn, are due to the newly-introduced landing obligation for all catches of TAC-regulated stocks. In this paper, the management implications of inter-species flexibility are evaluated by modelling various scenarios of individual and multiple multi-species fisheries exploiting virtual stocks of different sizes and productivity. The results reveal that IQF is rather ineffectual if sustainable stock-specific management goals are similar in terms of exploitation rate. However, if these goals are modified in response to potential ecological conservation needs or market considerations – which would reflect reality more closely – IQF may offer a frequently applicable and effective tool. Simulations carried out in this study demonstrate that IQF may support the use of quotas by increasing fishing opportunities of by-catch species, which are then subtracted from the target stock allowances. However, multiple and jointly managed multi-species fisheries frequently appear limited due to reduced fishing opportunities of target stocks, which may prevent the progressive application of IQF. As such, IQF is helpful for certain specific fisheries management, rather than as a tool for broader management approaches jointly applied to different fishing strategies. It is concluded that the application of IQF may undermine the politically-agreed and fixed quota-sharing rule among European member states (i.e. the “relative stability”) and also lacks a reference to FMSY; i.e., it remains to be clarified whether the application of IQF would result in tolerable levels of short term overfishing of by-catch stocks with regard to MSY.

North East Atlantic vs. Mediterranean Marine Protected Areas as Fisheries Management Tool

The effectiveness of management initiatives implemented in the context of the European Common Fisheries Policy has been questioned, especially with regard to the Mediterranean. Some of the analyses made to compare the fishing activity and management measures carried out in the North East Atlantic and in the Mediterranean do not take into account some of the differentiating peculiarities of each of these regions. At the same time, they resort to traditional fisheries management measures and do not discuss the role of marine protected areas as a complementary management tool. In this respect, the apparent failure of marine protected areas in the North-East Atlantic compared with the same in the Mediterranean is challenging European fishery scientists. Application of the classical holistic view of ecological succession to the functioning of fishery closures and no-use areas highlights the importance of combining both management regimes to fully satisfy both fishery- and biodiversity-oriented goals. We advocate that an optimal management strategy for designing an MPA to protect biodiversity and sustain fishing yields consists of combining a network of no-use areas (close to their mature state) with fish boxes (buffer zones maintained by fishing disturbance in a relatively early successional stage, where productivity is higher), under a multi-zoning scheme. In this framework, the importance of no-use areas for fisheries is based on several observations: 1) They preserve biological diversity at regional scale, at all levels –specific, habitat/seascape, and also genetic diversity and the structure of populations, allowing natural selection to operate. 2) They permit, the natural variability of the system to be differentiated from the effects of regulation and to be integrated in appropriate sampling schemes as controls. 3) They maintain the natural size and age structure of the populations, hence maximizing potential fecundity, allowing biomass export to occur from core to regulated areas, dampening the fluctuations derived from deviations from the theoretical optimal effort in the fishing zone.

Impacts of current EU regulation on the UK whitefish value chain

Cod and haddock are two of the “big 5” UK supermarket fish species and intrinsic to fish and chip shops nationwide. UK whitefish fleets produce a significant amount, however there is a reliance on imports to maintain supply. The UK is in a strong position to compete for raw material from Iceland and Norway given high prices paid for imports and investment by Icelandic and Norwegian companies in the UK. Regarding UK production of whitefish, the European Common Fisheries Policy landing obligation has introduced significant uncertainty. To avoid discarding of any quota stock, fishing may be stopped before all target stocks quota is reached. For demersal fleets, there is a transition period between 2016 and 18 where target stocks are introduced according to Advisory Council and EU agreement and Article 15, with all quota stocks from 2019. As the capacity of the fleets balance to the new regulations, supply will likely return and if maximum sustainable yield (MSY) is reached in 2020 then an increase in TACs from current levels is likely too. However, markets and industries can change in a short period. Particularly, most processing companies are small to medium size enterprises and those that concentrate on cod and haddock may have to adjust their business. Fleets could be resilient to such short term reductions in landings however this cannot be assumed. The competitiveness of producers will surely be affected in the short to medium term as a result.

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 analysed 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 FMSY for all species. Despite catch advice are produced by STECF each year, the realised 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.

Institutions and governance in the European Common Fisheries Policy: An empirical study of Spanish fishers' attitudes toward greater participation

Public participation in the decision-making process is a key element of good governance. In its latest proposals for reforming the Common Fisheries Policy, the European Commission acknowledges that management measures lack legitimacy without input from the fishers themselves and thus underscores the need to increase it and adapt it to local or regional conditions. This study analyzes Spanish fishermen's own views about their participation in the decision-making process. The results show that most fishers are in favor of more participation by themselves and by regional governments in the decision-making process.

Reflex impairment, physiological stress, and discard mortality of European plaice Pleuronectes platessa in an otter trawl fishery

AbstractThe reformed European Common Fisheries Policy introduced a discard ban, with a possibility of exempting species where a high discard survival can be demonstrated. This necessitates a validation of the methods used for estimating the discard mortality of candidate species. In this study, we assess whether reflex impairment can predict short-term mortality in commercially trawled European plaice upon landing and after air exposure of up to 90 min. Sub-lethal stress was assessed by a suite of physiological variables. Over a 10-day period, mortality was monitored for a total of 199 plaice following trawl and air exposure of varying duration, and for 50 control fish scored for reflex impairment on board the vessel. Mortality was only observed in fish exposed to air for >60 min, and averaged 11.1% (95% CI = 7.1–16.3%). Reflex impairment was found to be a significant (P < 0.001) predictor of mortality in a generalized linear model, excluding other initially included variables by using a stepwise method. Plasma cortisol, haematocrit, and plasma osmolality all indicated a profound and increasing level of stress with air exposure, accompanied by a near depletion of muscle phosphocreatine and nucleotides. Fishing site had an unexpected, but significant (p < 0.05) effect on stress levels, which was also reflected in reflex impairment and mortality. Based on these findings, a possible exemption from the discard ban should include considerations on the duration of air exposure.

Relative abundance and distribution of fisheries influence risk of seabird bycatch.

Fisheries provide an abundant and predictable food source for many pelagic seabirds through discards, but also pose a major threat to them through bycatch, threatening their populations worldwide. The reform of the European Common Fisheries Policy (CFP), which intends to ban discards through the landing obligation of all catches, may force seabirds to seek alternative food sources, such as baited hooks from longlines, increasing bycatch rates. To test this hypothesis we performed a combined analysis of seabird-fishery interactions using as a model Scopoli’s shearwaters Calonectris diomedea in the Mediterranean. Tracking data showed that the probability of shearwaters attending longliners increased exponentially with a decreasing density of trawlers. On-board observations and mortality events corroborated this result: the probability of birds attending longliners increased 4% per each trawler leaving the longliner proximity and bird mortality increased tenfold when trawlers were not operating. Therefore, the implementation of the landing obligation in EU waters will likely cause a substantial increase in bycatch rates in longliners, at least in the short-term, due to birds switching from trawlers to longliners. Thus the implementation of the landing obligation must be carefully monitored and counterbalanced with an urgent implementation of bycatch mitigation measures in the longline fleet.