Status of Fish Stocks in Europe (2018)

Infographics shows the status of the fish stocks in the EU waters as available in 2018.JRC.D.2-Water and Marine Resource

Evaluation and design of fisheries management plans: detecting the impact of management measures on fisheries dynamics using distance correlation.

The development and implementation of fisheries management plans can be expensive and time consuming. It is therefore essential to be able to determine if a plan has been effective in achieving its objectives. When the objectives of a management plan have been achieved (for example F, has been reduced to below some threshold level) it is important to determine if it was as a direct result of elements of the plan (for example, TAC restricting fishing mortality) or because of an external factor that was not included or considered by the plan (for example, fuel price rises causing a reduction in fishing effort). In the former case, we want to be able to understand which aspects of a management plan were effective so they can be considered in the design for future plans. In the latter case, there is the possibility of falsely attributing success to aspects of a plan that had no impact, thereby needlessly including them in the design of future plans. These issues can become more complicated in mixed fisheries where multiple gear types catch multiple stocks because interactions between the different biological and economic elements are not straightforward.JRC.G.3-Maritime affair

Analysis of success of achieving fishing mortality levels for the Northwest Mediterranean Multi-annual plan.

The evaluation of multi-annual plans to manage demersal fisheries performed by STECF (2016) is revisited to calculate an additional indicator of fishing mortality that better captures the effect of using ranges. The results presented are more aligned with the recent multi-annual plans objectives of providing flexible tactics. The analysis is still not a mixed fisheries analysis, it is an alternative approach to the one used by STECF (2016) which increases the degree of comparability across the different options, in particular across single point target approaches and value-range approaches.JRC.D.2-Water and Marine Resource

Compilation and quality check of the ICES stock assessment data

For the analysis of the CFP indicators for NE Atlantic stocks, stock assessment data had to be obtained from ICES. These data included time-series of stock size, fishing pressure and reference points for each stock. This document describes the compilation process of this dataset, including the data quality checks and corrections that were carried out.Embedded R code is executed to generate the polished ICES dataset used in the analysis for the CFP indicators report.JRC.D.2-Water and Marine Resource

Review of Progress in JRC Bioeconomic Modelling

1. Much of the bioeconomic modelling work performed at the JRC has been in relation to the evaluation of proposed multi-annual management plans for fisheries. These plans increasingly require the calculation and consideration of a range of economic indicators. A key element of this work is the parameterisation of the fisheries bioeconomic models. These models require a mix of economic, fisheries and biological data. The required data may be available in different data calls making it necessary to integrate data from different data sets. This integration can be performed using the common variables between the data sets, known as transversal variables. However, the different data sets can report the data at different aggregation levels. This makes linking the data sets challenging, particularly as the evaluation of a management plan requires the economic costs and revenues to be at the same scale as the plan. Modelling approaches have been developed to overcome the different levels of aggregation 2. The methods developed at the JRC for linking the data and parameterising the models were applied to STECF evaluations of multi-annual management plans in the North Sea and the Western Mediterranean. When the data is of a suitable quality the method works well even when the fisheries are complicated and involve multiple species being fished by multiple gears, for example with the North Sea evaluation. However, when the data is poor, for example with the Western Mediterranean evaluation, it is not possible to perform this type of analysis. This problem will remain unless the data collection process is improved. 3. Even when data is not missing there is the concern that it is being recorded differently by the member states, i.e. even within the same data set the data is not consistent. For example, Member States can interpret fishing effort differently. To help ensure consistency between data sets two workshops have been held on transversal variables. One of the outcomes of these workshops is a JRC led package for R, fecR, that will allow the transparent and repeatable calculation of two different types of fishing effort. 4. This report presents the experiences from two STECF EWG where the JRC modelling approaches has been used and the new R package for effort calculation.JRC.D.2-Water and Marine Resource

Uso de herramientas geostadísticas para evaluar diseños de muestreo aplicado a una experiencia

We present a bottom trawl survey (BTS) field experience carried out off the Portuguese Continental shelf to test two sampling designs proposals previously analysed by simulation which implement a hybrid random-systematic and a systematic sampling strategy. We used a common base regular grid covering the survey area and overlapped it with the existent random design to build the hybrid design while the systematic design added a set of regular locations at smaller distances creating four denser sampling areas. We use hake (Merluccius merluccius) abundance and model-based geostatistics to compute measures such as mean abundance, µ, and the 95% percentile, p95, which summarise the areal behaviour; coverage of the prediction confidence interval, ξ, to assess the adequacy of the model; and a modified generalised cross validation index, p, to evaluate prediction precision. The hybrid design showed a lower coefficient of variation for µ (11.89% against 13.25%); a slightly higher coefficient of variation for p95 (11.31% against 11.09%); similar ξ (0.94); and lower π (16.32 against 18.82). We conclude that the hybrid design performs better, our procedure for building it can be used to adjust BTS designs to modern geostatistical techniques, and the statistics used constitute valuable tools for assessing BTS performance.Presentamos una experiencia de campo mediante campañas de arrastre demersal (CAD) llevada a cabo en la plataforma continental portuguesa con el fin de evaluar dos propuestas de diseño de muestreo. Las dos propuestas se analizaron previamente mediante técnicas de simulación implementando dos estrategias de muestreo: estrategia híbrida aleatoria-sistemática y estrategia sistemática. Se utilizó una rejilla de celdas regular común cubriendo el área de estudio y se superpuso con el diseño aleatorio existente para construir el diseño híbrido, mientras que el diseño sistemático añade un conjunto de puntos de muestreo regulares a menor distancia para crear cuatro áreas de muestreo más densas. Se usa la abundancia de merluza (Merluccius merluccius) y técnicas geostadísticas basadas en modelo para calcular medidas como: abundancia media, µ, y el percentil 95%, p95, que resumen el comportamiento areal; la cobertura del intervalo de confianza de predicción, ξ, para evaluar la bondad del modelo; y un índice modificado de validación cruzada generalizada, π, para evaluar la precisión de la predicción. Se obtuvo un coeficiente de variación menor para µcon el diseño híbrido (11.89% frente a 13.25%); un coeficiente de variación ligeramente más alto para p95 (11.31% frente a 11.09%); una ξ similar (0.94); y menor π (16.32 contra 18.82). se concluye que el diseño híbrido funciona mejor y nuestro procedimiento para construirlo puede ser usado para ajustar diseños CAD a técnicas geostadísticas modernas, y que los estadísticos usados constituyen herramientas valiosas para evaluar el rendimiento de CAD

Endogenous Fishing Mortalities: a State-Space Bioeconomic Model

A methodology that endogenously determines catchability functions that link fi shing mortality with contemporaneous stock abundance is presented. We consider a stochastic age-structured model for a fishery composed by a number of fi shing units (fleets, vessels or métiers) that optimally select the level of fishing effort to be applied considering total mortalities as given. The introduction of a balance constrain which guarantees that total mortality is equal to the sum of individual fi shing mortalities optimally selected, enables total fishing mortality to be determined as a combination of contemporaneous abundance and stochastic processes affecting the fishery. In this way, future abundance can be projected as a dynamic system that depends on contemporaneous abundance. The model is generic and can be applied to several issues of fisheries management. In particular, we illustrate how to apply the methodology to assess the floating band target management regime for controlling fishing mortalities which is inspired in the new multi-annual plans. Our results support this management regime for the Mediterranean demersal fishery in Northern Spain.This work was funded by the European Commission as part of the MINOUW project (H2020-SFS-2014-2, number 634495) and the Spanish Ministry of Economy, Industry and Competitiveness (ECO2016-78819-R, AEI/FEDER, UE

Scientific, Technical and Economic Committee for Fisheries (STECF) - Report of the Working Group on Balance between Resources and their Exploitation (SGBRE) - Northern Hake Long-term Management Plans (SGBRE-07-03)

SGBRE-08-03 was held on 4-8 June 2007 in Lisbon (Portugal). The meeting was focusing on the assessment of the impact of long-term management plans on northern hake stocks. STECF reviewed the report during its plenary meeting 18-22 June 2007.JRC.G.4-Maritime affair

Generating the CFP indicators sampling frame for FAO area 27 (Northeast Atlantic)

For the analysis of the CFP indicators it is necessary to generate the sampling frame. The sampling frame is the collection of species in EU Fisheries Managment Zones (FMZ) for which the CFP is at least partially responsible for their management. This document describes the generation of the sampling frame. Embedded R code is executed to generate the sampling frame.JRC.D.2-Water and Marine Resource

Applications of spatial statistics to fish abundance: improving the abundance indices of hake, Merluccius merluccius (Linnaeus, 1758), off the portuguese continental coast

Tese dout., Ciências e Tecnologias das Pescas, Universidade do Algarve, 2009Este trabalho contribui para a melhoria do conhecimento sobre abundância de populações de peixe e o seu uso para gestão pesqueira. Geoestatística model-based e simulações estocásticas são utilizadas de forma generalizada e aplicadas à pescada (Merluccius merluccius Linnaeus, 1758) e às campanhas demersais na costa continental Portuguesa. O Capítulo 2 apresenta um estudo de simulação que explora planos de amostragem alternativos para campanhas demersais. O Capítulo 3 apresenta uma experiência realizada numa campanha demersal onde uma parte dos planos amostrais anteriores foi testada. Ambas análises concluiram que um plano amostral híbrido aleatório-sistemático apresenta melhor performance na estimação da abundância de pescada. O Capítulo 4 apresenta um modelo espaço-tempo-idade para estimar abundância, com uma distribuição conjunta dada pelo producto da distribuição da abundância agregada e a distribuição condicional de proporções por idade, modeladas com geoestatística e análise de dados composicionais, respectivamente. No Capítulo 5, estratégias de gestão passíveis de recuperar o manancial de pescada Ibérica para níveis de biomass sustentáveis são avaliados e a sua robustez relativamente a incerteza na informação de capturas e dinâmica do manacial testada. Os resultados mostram que reduzir a a mortalidade por pesca é absolutamente essencial para recuperar o manancial. Complementarmente, reduzir as rejeições ao mar conduzirá a pescaria a desembarques de maior valor, associados a custos de exploração mais baixos. No Capítulo 6 são apresentadas as conclusões gerais.IPIMA