RIM20_7Author /Editor: Luis Ferrer, Nagore Zaldua-Mendizabal, Andrea del Campo, Javier Franco, Julien Mader, Unai Cotano, Adolfo Uriarte and José Antonio Aranda

Year: 2013

ContentPhysalia physalis, commonly known as the Portuguese man-of-war, is a colonial organism (cnidarian), greatly feared for the severity of its stings, that consists of a gas-filled sail-like float on top and a suspended part formed by specialized polyps and long defending and hunting tentacles. This paper describes the operational protocol established during the summer in the southeastern Bay of Biscay (and especially along the Basque Country coast) for its sighting and tracking. This action protocol combines the cooperation among several civil society stakeholders, including fishermen (from Spain and France), with the results of ocean and atmosphere circulation models. In this case, hourly sea surface currents and winds obtained with the ROMS (Regional Ocean Modeling System) and WRF (Weather Research and Forecasting) models, respectively, are used in a Lagrangian particle-tracking model to estimate the drifting of Portuguese men-of-war and their impact on the most popular beaches of the Basque Country.

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RIM20_6Author /Editor: Naiara Rodriguez-Ezpeleta, Iñaki Mendibil, Paula Álvarez and Unai Cotano (AZTI-Tecnalia)

Year: 2013

Content: Population genomics experiments of non-model organisms, such as most commercial fish, rely on isolating good integrity DNA from the study subjects. Yet, this task is not trivial as, when an organism dies, its DNA starts breaking down in small pieces. This process is called DNA degradation and can fortunately be stopped or slowed down by preserving the samples in cold and/or dry conditions. Here, we have assessed the effect of tissue type, storage time, preserving conditions and post-mortem intervale in fish DNA integrity. From the four factors tested, post-mortem intervale is the one that most drastically affects DNA integrity, tissues sampled after 24 hours of death yielding partial or totally degraded DNA. In order to preserve DNA integrity, we provide some recommendations to be considered when sampling fish tissue for genetic analysis.

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Rim20_5Author /Editor: Manuel González and Almudena Fontán (AZTI-Tecnalia)

Year: 2013

Content: In climatic time-series (atmospheric and sea surface temperature, sea level, atmospheric pressure, etc.), variability ranging from hours, days, months, seasons to several years can be detected. The present study discusses the application of symmetric digital filters, especially designed for daily time-series, such as the atmospheric temperature of the Observatory of Igueldo (1928-2012), to suppress variability with periods of less than a given period. The results of the spectral analysis show that the application of the filter, in time-series with a low proportion of gaps (less than 1%), permits to eliminate the variability below the cut-off period, with a low computational cost. However, the length of the window required for the digital filtering is relatively long (between 3 and 5 times the cut-off period). This leads to loss of information at the beginning and at the end of the time-series.

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Rim20_4Author /Editor: Lucía Zarauz, Raúl Prellezo, Estanis Mugerza, Iñaki Artetxe, Ruben Roa, Leire Ibaibarriaga and Luis Arregi (AZTI-Tecnalia)

Year: 2013

Content: This study outlines a biological, economic and social portrait of the recreational boating and fishing in the Basque Country. It is a review work covering the description of the legal framework, the realization of a detailed census of the fleet, the characterization of the fleet and its activity, and the estimation of the impacts on the economy and the biological resources. A first set of data for the census was obtained from the Libro de Registro Segundo of the year 2008, and was completed with direct observations and satellite pictures (Google Earth).

The characterization of the fleet and its activity was performed by a survey carried out during 2008 and 2009. Catches of main target species were estimated by means of a two-step GLM (binomial and log-lineal). Direct and indirect economic impacts were estimated separately by applying linear models. Results show that recreational boating and fishing are predominantly a male activity and that familiar tradition is an important factor.

This activity has an impact of over 60 million euros on the economy. The highest expenses are due to fuel costs for motorboats, and to owing costs for sail boats. From the point of view of the catches, squids (113 t), albacore (89 t) and mackerel (72 t) are the main target species. The weight and the composition of the catch are different depending on the type of boat and its length. Small motorboats and txipironeras are characterized by a higher effort (fishing days by boat and year), whereas the largest catches (kg by boat and year) are obtained by large motorboats. Despite the limitations of this study, recreational boating and fishing are highlighted as an important activity which should be taken into account in marine management plans for the Basque Country.

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Rim20_3Author /Editor: Estíbaliz López de Abechuco, Manuel Soto, Miguel Angel Pardo, Mark Haussmann and Guzmán Díez

Year: 2013

Contenido:

Telomere length measurement has been proposed as a promising tool to estimate the age of individuals in natural populations. We used real-time quantitative PCR (qPCR) to measure relative telomere length in four tissues (brain, kidney, liver and muscle) of European hake (Merluccius merluccius) in different groups based upon body length an otolith age estimate.

We observed a high level of inter-individual differences in the measurements of relative telomere length in hakes of similar age and body length groups. The results of qPCR analysis showed a great variability in all measures and a lack of repeatability and reproducibility with significant statistical differences in the results of the different assays. The paper discusses the technical reasons for the variability in qPCR obtained in this work and by other authors.

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rim20_2Author /Editor: Ane Iriondo, Martín Aranda and Marina Santurtún (AZTI-Tecnalia)

Year: 2013

Content: Since year 2006, Spanish offshore fleets are assigned individual fishing quotas for certain ground fish species. This allocation is made based on fishing opportunities of each vessel on certain fishing coefficients of the International Council for the Exploration of the Sea (ICES) areas VI, VII and VIII. This study explains the procedure followed in the allocation of individual fishing quotas, to know the annual allocation in weight by species and vessel. This knowledge could help improving the management advice of mixed fisheries working with fishing quotas of various species together.

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rim20_1Autor /Editor: Joxe Mikel Garmendia, Mireia Valle, Ángel Borja, Guillem Chust y Javier Franco (AZTI-Tecnalia)

Año: 2013

Contenido: Las praderas marinas son importantes para el ecosistema marino por las funciones ecológicas que desempeñan (hábitat y alimento de algunas especies, producción primaria, resistencia a la erosión del sedimento, ciclo de nutrientes…). En el País Vasco, solo 3 de los 12 estuarios cuentan con estos valiosos ecosistemas, que corresponden a praderas marinas intermareales de la especie Zostera noltii, incluida en el Catálogo de Especies Amenazadas del País Vasco como especie en peligro de extinción. Su escasez y vulnerabilidad elevan aún más el interés por su estudio y conservación. Por ello, en 2008 y 2012 se realizaron sendos estudios de detalle sobre la presencia y distribución de esta planta en los estuarios vascos: como resultado, en 2012 se estima una superficie total de 19,79 ha ocupada por Zostera noltii, de la cual un 86,9% se encuentra en el Oka, un 9,9% en el Bidasoa y un 3,2% en el Lea. Entre los años 2008 y 2012 se ha constatado una disminución de 2,88 ha en su extensión total en el País Vasco: en el Bidasoa la superficie de pradera ha aumentado en 0,13 ha; en el Lea también ha aumentado su superficie, en 0,48 ha; en el Oka la superficie ha aumentado en 0,12 ha en la zona de Kanala, habiendo disminuido 2,3 ha en la zona de San Kristobal y 1,33 ha en la zona de Arketas. A pesar de la disminución neta observada (10%), las poblaciones de los estuarios vascos presentan una elevada tasa de cambio (53,1%) frente a la fracción estable de la pradera (46,9%). Dados los impactos a los que se ven expuestas las praderas, se recomienda realizar campañas de sensibilización y concienciación ambiental para velar por la conservación de la especie.

Contacto: biblioteca@azti.es

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rim19_7Author /Editor: Haritz Arrizabalaga, Hilario Murua and Jacek Majkowski

Year: 2012

Content: Tuna stocks are harvested by many countries in all oceans and managed by Regional Fishery Management Organizations (RFMOs). The FAO Fisheries & Aquaculture Department periodically reviews the state of world marine fishery resources, which includes a summary chapter for tunas and tuna like species. This world summary requires a review and synthesis of assessment reports, as well as additional preparatory work which is not then documented elsewhere. Thus, the objective of the present publication is to present the information used and summarized by FAO. It essentially includes a review of worldwide tuna catch, fisheries and stock status for the most commercially important 23 tuna populations, which was done between late 2010 and early 2011. The review not only focuses on the stock status, but also on its evolution over time. On one hand, time trends on the stock status (as perceived in the stock assessments available by early 2011) are summarized, focussing on three reference periods. In addition to this, and when enough stock assessment information is available for the historic period, the early 2011 perception of stock status is compared with the stock status as perceived in stock assessments conducted in the past, allowing a retrospective analysis

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rim19_7Author /Editor: Manuel González, Jordi Blasco, Andrea Del Campo,Manuel Espino, Luis Ferrer, Almudena Fontán, Arnel Germán, Carlos Hernández,Augusto Maidana and Marta Revilla

Year: 2012

Content: The application of a spurious-mode free Finite Element Model (FEM), for the determination of water residence time in Pasaia Bay (SE Bay of Biscay), is presented. Pasaia Bay is a sheltered harbour area, highly anthropogenically-affected, where the astronomical tide is the main forcing mechanism controlling water renewal. The numerical simulation of the currents generated by tides has been performed using also a FEM to solve the shallow water equations. The results obtained have been used to solve the convention-diffusion equation, by means of a linear technique for explicit Flux-Corrected Transport (FEM-FCT). This technique permits the analysis of dispersion in appropriate spatio-temporal scales, according to the harbour domain and assuming that the tidal influence on the currents is high.

In order to determine the horizontal dispersion coefficient, this method of numerical simulation has been used to estimate the turbidity dispersion in the bay, validating the results with in-situ measurements. Finally, the model has been applied to estimate the water residence time, obtaining values of about 4.5 days without diffusion and 60 days with the horizontal diffusion coefficient (0.05 m2•s-1) obtained from the turbidity simulations. The FEM-FCT technique used has limitations related to the maximum admissible time-step, making the computational time useful for simulation of hydrodynamic scenarios, but being inappropriate for operational applications.

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rim19_6Author / Editor: Ángel Borja (Editor)

Year: 2012

Content: AZTI-Tecnalia organizes the XVII edition of SIEBM – Iberian Symposium on Marine Biology Studies, in Donostia – San Sebastián, from 11 th to 14 th September 2012. The conference has been organized within the Summer School of the Basque Country University, which takes place every year in San Sebastián.

The objectives of the Symposia are to show the recent advances in marine biology research, within the Iberian Peninsula (Portugal, Spain and the Maccaronesian islands) and also South American countries.

The research topics covered by the Symposium, divided in scientific sessions, include aquaculture and parasitism; benthic ecology; ecological assessment, environmental impacts and pollution monitoring; genetics and taxonomy; global change; management of living resources; modelling and habitat suitability; pelagic ecology; restoration, conservation and planning; and, finally, a miscellaneous section

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