FLBEIA fisheries management simulation model. Definition of new criteria and guidelines for efficient validation of the model using global sensitivity analysis

229 p.En esta tesis se ha desarrollado el modelo bio-económico de simulación pesquera FLBEIA y se han definido una serie de direcciónes para validarlo y fomentar la validación de los modelos de simulación pesquera. El modelo FLBEIA da respusta a la necesidad de modelos de este tipo identificada en el marco de los análisis de impacto llevado a cabo por la Comisión Europea para anticipar la eficacia de las estrategias de gestión pesquera. La modelización de la incertidumbre ha sido un punto clave en el desarrollo del modelo FLBEIA sigue la aproximación de evaluación de estrategias de gestión que formaliza la incorporación de la incertidumbre en el proceso de toma de decisiones. Al ser los modelos de simulación abtracciones de la realidad, no son capaces de describir el sistema real de manera perfecta y es necesario validarlos para asegurar que representan el sistema modelado de manera idónea. El análisis de sensibilidad global es una de las técnicas cuantitativas más utilizadas en la validación de modelos de simulación. Sin embargo, su uso en modelos pesqueros es escaso. El conjunto de directrices definitivas en esta tesis permite condicionar los modelos pesqueros de manera efectiva y combinar dos de los métodos de análisis de sensibilidad global más utilizados. La combinación de estos métodos permite identificar los factores de entrada que más impactan en los resultados del modelo con un coste computacional aceptable para disponer de un modelo reducido al cual poder aplicar posteriormente el método más costoso. El modelo FLBEIA y las directrices propuestas se han aplicado a la pesquería demersal que opera en la fachada atlántica de la península ibérica

FLBEIA fisheries management simulation model. Definition of new criteria and guidelines for efficient validation of the model using global sensitivity analysis

229 p.En esta tesis se ha desarrollado el modelo bio-económico de simulación pesquera FLBEIA y se han definido una serie de direcciónes para validarlo y fomentar la validación de los modelos de simulación pesquera. El modelo FLBEIA da respusta a la necesidad de modelos de este tipo identificada en el marco de los análisis de impacto llevado a cabo por la Comisión Europea para anticipar la eficacia de las estrategias de gestión pesquera. La modelización de la incertidumbre ha sido un punto clave en el desarrollo del modelo FLBEIA sigue la aproximación de evaluación de estrategias de gestión que formaliza la incorporación de la incertidumbre en el proceso de toma de decisiones. Al ser los modelos de simulación abtracciones de la realidad, no son capaces de describir el sistema real de manera perfecta y es necesario validarlos para asegurar que representan el sistema modelado de manera idónea. El análisis de sensibilidad global es una de las técnicas cuantitativas más utilizadas en la validación de modelos de simulación. Sin embargo, su uso en modelos pesqueros es escaso. El conjunto de directrices definitivas en esta tesis permite condicionar los modelos pesqueros de manera efectiva y combinar dos de los métodos de análisis de sensibilidad global más utilizados. La combinación de estos métodos permite identificar los factores de entrada que más impactan en los resultados del modelo con un coste computacional aceptable para disponer de un modelo reducido al cual poder aplicar posteriormente el método más costoso. El modelo FLBEIA y las directrices propuestas se han aplicado a la pesquería demersal que opera en la fachada atlántica de la península ibérica

Standardized CPUE Indices for Greenland Halibut in NAFO Divisions 3LMNO Based on Spanish Commercial Catch Rates

Standardized CPUE series using a Generalized Linear Model for Greenland halibut in Div. 3LMNO, based on catch and effort data from the Spanish trawl fleet since 1991 are presented. Fixed factors considered in the model were: year, month, vessel, Division and depth and the interactions analysed were: Division – depth and month – Division. All the factors and interactions analyzed are significant. The total proportion of variance explained by this model was 40%. The results indicate a decrease trend in the catch rate index in recent years from highest values in 2000

Evaluación bioeconómica del cambio en la selectividad de un arte de pesca: el caso de una flota mono-específica afectada por la obligación de desembarque

The European Union Common Fisheries Policy has established a discard ban, which states that fish below a reference size cannot be sold directly for human consumption. In a fishing effort-regulated fishery, the discard ban can result in extra handling, storing and landing costs. In an output-regulated fishery, this policy might also limit the effort levels as all the catches count against the quota. In both cases, this regulation can reduce the economic performance of the companies, even in single-species fisheries. A possible solution is to increase the mesh size, thus retaining fewer small individuals. To study this option, a bioeconomic simulation of a change in the gear selectivity from 100- to 120-mm minimum mesh size (MMS) was performed. The results show that the private perspective (profits) does not change. Furthermore, due to the lower retention of 120 mm MMS, the efficiency of a fishing day was reduced by 5% and 2.5%, from the point of view of capital and labour productivity, respectively. In contrast, gross revenues increased by 1.5% and crew compensation by 2%. Given a societal benefit of this change in the mesh size, this gain could be re-distributed to provide an incentive for selectivity improvements.La Política Pesquera Común de la Unión Europa ha introducido la prohibición de descartar, estableciendo que todo pescado por debajo de una talla de referencia no puede ser vendido para consumo humano directo. En una pesquería regulada a través de limitaciones del esfuerzo de pesca, la prohibición de descartar puede generar sobrecostes de manipulación, almacenamiento y desembarque adicionales. En una pesquería regulada a través de límites en las capturas, esta política podría incluso limitar los niveles de esfuerzo ya que todas las capturas deben ser deducidas de la cuota. En ambos casos, esta regulación puede reducir el resultado económico de las empresas, incluso en el caso de una pesquería mono-específica. Una posible solución sería aumentar el tamaño mínimo de la malla, y así reducir la retención de los individuos más pequeños. Con el fin de estudiar esta opción, se ha realizado una simulación bioeconómica de un cambio en el tamaño mínimo de la malla de 100 a 120-mm. Los resultados muestran cómo la perspectiva económica privada (beneficios) no varía. Más aun, debido a la menor retención de la malla de 120 mm, la eficiencia de un día de pesca se ve reducida en un 5% y en un 2.5%, desde el punto de vista de la productividad del capital y del trabajo, respectivamente. Por el contrario, los beneficios brutos aumentan un 1.5% y la remuneración al trabajo en un 2%. Debido a la existencia de un beneficio social, la ganancia podría ser redistribuida para así ofrecer un incentivo a esta mejora de la selectividad

Estimating life history parameters of European hake using Bayesian models

Sustainability and Maximum Sustainable yield (MSY) are nowadays the main fishery management goals, which are mainly addressed through single stock assessment models. However, there is a need of increasing the number of stocks assessed and improve the quality of existing assessments. The stock assessment is based on models that link the fishing activity to population dynamics based on biological processes. A common problem when starting to develop a stock assessment model for a specific species is that the biological knowledge for some processes is poor or even absent (frequently for M but also growth). In these cases, the lack of prior knowledge can be replaced with empirical estimates. The theory of life history invariants states (in general) that for a similar taxa, k/M and Lm/Linf tend to be relatively constant. This theory highlights two helpful considerations: one that whether you know one parameter you can estimate the other and two that those parameters cannot vary since they are correlated. Within this frame, life history invariants theory and hierarchical Bayesian models can be combined to better understand biological processes needed in most stock assessment models (maturity, growth and natural mortality) providing the required parameters together with their statistical structure (posterior distributions). In order to perform this meta-analysis, bibliographic life history parameters for different hake species all over the world have been collected and analysed. The results of these parameters could be useful to help in the configuration of biological processes of hake stock assessment models

To shape or to be shaped : engaging stakeholders in fishery management advice

The purpose of this paper is to assess the effectiveness of the collaboration between stakeholders and scientists in the construction of a bio-economic model to simulate management strategies for the fisheries in Iberian Atlantic waters. For three years, different stakeholders were involved in a model development study, participating in meetings, surveys and workshops. Participatory modelling involved the definition of objectives and priorities of stakeholders, a qualitative evaluation and validation of the model for use by decision-makers, and an iterative process with the fishing sector to interpret results and introduce new scenarios for numerical simulation. The results showed that the objectives of the participating stakeholders differed. Incorporating objectives into the design of the model and prioritising them was a challenging task. We showed that the parameterization of the model and the analysis of the scenarios results could be improved by the fishers’ input: e.g. ray and skate stocks were explicitly included in the model; and the behaviour of fleet dynamics proved much more complex than assumed in any traditional modelling approach. Overall, this study demonstrated that stakeholder engagement through dialogue and many interactions was beneficial for both, scientists and the fishing industry. The researchers obtained a final refined model and the fishing industry benefited for participating in a process, which enables them to influence decisions that may affect them directly (to shape) whereas non-participatory processes lead to management strategies being imposed on stakeholders (to be shaped)

Results of the 3M Cod MSE

The general objective of the 3M Cod MSE is to maintain the SSB of this species in the safe zone as defined by the NAFO precautionary approach framework and to assure the optimum utilization, rational management and conservation of the 3M cod stock. Based on this, five performance objectives were tested via five different Performance Statistics. Six different OMs and two HCRs with three different Ftarget were tested. The six OMs come from different assumptions over M and over the Stock-Recruitment relationship (SRR). The two HCRs are one model-based (based on the Bayesian XSA model approved by SC) and one model-free (based on the EU-FC survey). A 20% constraint of annual variation of TAC was set for both HCR. Based on this, a total of 24 scenarios were tested and results projected for the period 2014-2025. Differences in the results come mainly from the assumed stock recruitment relationship and in a much lesser extent of assumed M and the different Ftarget levels tested. The SSB have an increasing trend in all cases reaching a level well above Blim at the end of the projected period. There are two main trends in yields, one for the scenarios with the model-based HCR and other for the scenarios with the model-free HCR. In the first case, landings decrease to 6 500 tons in 2020, and after that increase until 2025 reaching a value between 10 500 and 15 000 tons, depending on the SRR assumed. In the case of the model-free HCR, until 2023 the decrease is very small and then a quiet constant value between 5 000 and 11 000 tons is reached. None of the tested HCR reached the established performance objectives in the 2016-2023 period but most of the scenarios met the performance objectives after 2024. The main reasons for not achieving these objectives are the high initial F and catch levels and the 20% catch constraint. The necessary period to achieve the performance objectives would be longer if we had applied a more restrictive TAC constraint (15% or 10%). If the TAC constraint is not applied, lower landings are allowed in the short-term period (2016-2020), but after that the increase in TAC is higher than if the constraint is applied

Bioeconomic multistock reference points as a tool for overcoming the drawbacks of the landing obligation

The landing obligation policy was one of the major innovations introduced in the last Common Fisheries Policy reform in Europe. It is foreseen that the policy will affect the use of fishing opportunities and hence the economic performance of the fleets. The problem with fishing opportunities could be solved if single-stock total allowable catches (TACs) could be achieved simultaneously for all the stocks. In this study, we evaluate the economic impact of the landing obligation policy on the Spanish demersal fleet operating in the Iberian Sea region. To generate TAC advice, we used two sets of maximum sustainable yield (MSY) reference points, the single-stock MSY reference points defined by ICES and a set of multistock reference points calculated simultaneously using a bioeconomic optimization model. We found that the impact of the landing obligation is time and fleet dependent and highly influenced by assumptions about fleet dynamics. At fishery level, multistock reference points mitigate the decrease in the net present value generated by the implementation of the landing obligation. However at fleet level, the effect depends on the fleet itself and the period. To ensure the optimum use of fishing opportunities, the landing obligation should be accompanied by a management system that guarantees consistency between single-stock TACs. In this regard, multistock reference points represent an improvement over those currently in use. However, further investigation is necessary to enhance performance both at fleet level and in the long term.Versión del edito

Remodeling arteries: studying the mechanical properties of 3D-bioprinted hybrid photoresponsive materials.

3D-printed cell models are currently in the spotlight of medical research. Whilst significant advances have been made, there are still aspects that require attention to achieve more realistic models which faithfully represent the in vivo environment. In this work we describe the production of an artery model with cyclic expansive properties, capable of mimicking the different physical forces and stress factors that cells experience in physiological conditions. The artery wall components are reproduced using 3D printing of thermoresponsive polymers with inorganic nanoparticles (NPs) representing the outer tunica adventitia, smooth muscle cells embedded in extracellular matrix representing the tunica media, and finally a monolayer of endothelial cells as the tunica intima. Cyclic expansion can be induced thanks to the inclusion of photo-responsive plasmonic NPs embedded within the thermoresponsive ink composition, resulting in changes in the thermoresponsive polymer hydration state and hence volume, in a stimulated on-off manner. By changing the thermoresponsive polymer composition, the transition temperature and pulsatility can be efficiently tuned. We show the direct effect of cyclic expansion and contraction on the overlying cell layers by analyzing transcriptional changes in mechanoresponsive mesenchymal genes associated with such microenvironmental physical cues. The technique described herein involving stimuli-responsive 3D printed tissue constructs, also described as four- dimensional (4D) printing, offers a novel approach for the production of dynamic biomodels.Financial support is acknowledged from the MCIN/AEI/ 10.13039/501100011033 through grant # PID2019-108854RAI00. C. G. A. thanks to the Ministerio de Ciencia e Innovacio´n (MCIN) for a Juan de la Cierva Incorporacio´n Fellowship (IJC2019-040827-I). M. S.-A. is recipient of a Ramo´n y Cajal contract and a ‘‘Generacio´n de Conocimiento’’ grant from the Ministerio de Ciencia e Innovacio´n (RYC2020-029690-I and PID2021-128106NA-I00). MAdP is coordinator and PL of ‘‘AtheroConvergence’’ La Caixa Foundation Health Research consortium (HR20-00075). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the MCIN and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (grant CEX2020-001041-S). We acknowledge ALBA for provision of synchrotron radiation facilities. We would like to thank Dr Marc Malfois for assistance in using BL11-NCD beamline, and Unai Cossı´o and Daniel Padro for help with image analysis.S