Changes in the juvenile fish assemblage of a Mediterranean shallow Posidonia oceanica seagrass nursery area after half a century

The within-year dynamics of the juvenile fish community in a shallow seagrass-dominated nursery habitat (Posidonia oceanica) in a Mediterranean bay were compared between two surveys separated by 50 years (1960 and 2012-2013). A nocturnal survey over depths ranging from 2 to 10 m over patchy seagrass meadows was conducted for one year (2012-2013) through 72 epibenthic tows spread fortnightly in 4 nearby stations, mimicking a survey conducted in 1960 in terms of sampling intensity, sampling zone, temporal coverage and sampling gear. Although a large proportion of the fish species were similar among surveys, remarkable and statistically significant differences were detected. A striking feature was that one of the most common and abundant Sparidae species currently, Diplodus annularis, did not appear in 1960. Other strong differences included the nonappearance of the European eel Anguilla anguilla in the recent survey. Furthermore, one of the most valuable species for artisanal fisheries in the area, the black scorpionfish Scorpaena porcus, was almost 10 times less abundant in 1960. A finer-scale study of the 2012-2013 survey allowed a quantitative analysis between species composition and potential environmental drivers through redundancy analysis that well described the current pattern of time-dependent recruitment pulses in nearshore meadows of the area throughout the year, with marked effects of surface temperature and photoperiod. The comparison between surveys suggests that some major differences between surveys are not likely to be attributable to interannual stochasticity in recruitment or environmental variability but may be related to i) unaccounted-for habitat transformation and/or ii) the strong decrease in juvenile fishing mortality in this shallow nursery area since the enforcement of bans on littoral epibenthic trawling activities characteristic of this area

Circular Economy and Value Creation: Sustainable Finance with a Real Options Approach

This paper presents a methodological proposal that integrates the circular economy concept and financial valuation through real options analysis. The Value Hill model of a circular economy provides a representation of the course followed by the value of an asset. Specifically, after the primary use, the life of an asset may be extended by going through four phases: the 4R phases (Reuse, Refurbish, Remanufacture and Recycle). Financial valuation allows us to quantify value creation from firms' asset circularity under uncertainty, modelled by binomial trees. Furthermore, the 4R phases are valued as real options by applying no-arbitrage opportunity arguments. The major contribution of this paper is to provide a quantitative approach to the value of circularity in a general context, but adaptable to firms' specific situations. This approach is also useful for trans-lating relevant information for stakeholders and policy makers into something with economic and financial value

Nuevos datos sobre la presencia de Pontinus kuhlii (Bowdich, 1825) (Osteichthyes: Scorpaenidae) en el Mediterráneo Occidental

The second documented capture of one specimen of Pontinus kuhlii (Bowdich, 1825) (Osteichthyes: Scorpaenidae) is reported from the Western Mediterranean, including a description of the specimen and formulating a hypothesis about the distribution of this species in the area.Se presenta la segunda cita documentada de un ejemplar de Pontinus kuhlii (Bowdich, 1825) (Osteichthyes: Scorpaenidae) para el Mediterráneo Occidental, incluyendo una descripción del ejemplar y formulando una hipótesis sobre la distribución de esta especie en el área

First record of an adult specimen of Luvarus imperialis Rafinesque, 1810 in Balearic waters (Western Mediterranean). Anatomical and biological considerations

Abstract not availabl

Reaching professional skills with the Final Master Thesis: Collaboration towards actual solutions

[EN] In order to motivate the student through a professional experience, and to improve the teaching-learning process by letting the student gain experience, we implement a collaborative learning-through-service methodology. This method increases the student involvement level and the deep understanding of the tools. As a matter of example, we present the implementation of this method in the Final Master Thesis (FMTh) of the Master on Corporate Finance at the University of Valencia (UV). In these FMTh, students have to valuate an actual innovation developed by UV researchers (on chemistry, in this case) with the goal of helping them to transfer (sell) this innovation to the industry. This collaborative learning-through-service methodology helps students put into practice the technics learned in the Master and give them a strong sense of the financial professional practice.The authors acknowledge financial support from University of Valencia Vicerrectorado de Políticas de Formación y Calidad, UV-SFPIE_RMD17-589360.Comeig-Ramírez, I.; Grau-Grau, AJ.; Pinar-García, L.; Ramírez-López, F.; Rodrigo-González, A. (2019). Reaching professional skills with the Final Master Thesis: Collaboration towards actual solutions. En INNODOCT/18. International Conference on Innovation, Documentation and Education. Editorial Universitat Politècnica de València. 107-117. https://doi.org/10.4995/INN2018.2018.8829OCS10711

Rasgos reproductivos de los gobios paedomórficos explotados en la pesquería del jonquillo de Mallorca (Mediterráneo occidental) y sus implicaciones en la gestión

An important small-scale fishery in Majorca targets three similar goby species: Aphia minuta, Pseudaphia ferreri and Crystallogobius linearis. Histological examination of the gonads of these species sampled from landings during the fishing season revealed characteristic reproductive traits that could be defined as abbreviate iteroparity. The transparent goby (Aphia minuta) and Ferrer’s goby (Pseudaphia ferreri) showed batch abbreviate iteroparity as a reproductive strategy, whereas the crystal goby (Crystallogobius linearis) showed total abbreviate iteroparity. Despite their short lifespans, all of them have a spawning season whose duration is longer than the legal fishing season. Additionally, all of them maintain a standing stock of primary growth oocytes in their gonads, indicating more than one spawning season in their lifespan. These reproductive features partially offset their special sensitivity to potential overexploitation and environmental changes but also suggest that the fishery needs special management to avoid breaking the balance between sustainability and fishing effort. The results of size at maturity and potential annual fecundity in the three species of the fishery are also reported and discussed.En Mallorca existe una importante pesquería artesanal basada en la captura de 3 especies de gobios similares (Aphia minuta, Pseudaphia ferreri y Crystallogobius linearis). El examen histológico de las gónadas de muestras obtenidas de los desembarques realizados durante la temporada de pesca reveló rasgos reproductivos característicos que podrían definirse como iteroparidad abreviada. El chanquete o jonquillo (Aphia minuta) y el cabotí (Pseudaphia ferreri) mostraron una estrategia reproductiva de iteroparidad abreviada múltiple, mientras que el gobio de cristal (Crystallogobius linearis) mostró iteroparidad abreviada total. A pesar de su corta esperanza de vida, todos ellos tienen una larga época de puesta, cuya duración es mayor que la temporada de pesca autorizada. Además, todos ellos mantienen una reserva permanente de ovocitos de crecimiento primario en sus gónadas, lo que indica más de un período de puesta a lo largo de su vida. Estas características reproductivas compensan en parte su especial sensibilidad a posibles sobreexplotaciones y cambios ambientales, pero al mismo tiempo implican la necesidad de una gestión especial de la pesquería para evitar romper el equilibrio entre sostenibilidad y esfuerzo pesquero. También se reportan y discuten los resultados de talla de madurez y fecundidad anual potencial en las tres especies de la pesquería

Study of the n-3 highly unsaturated fatty acids requirement and antioxidant status of Dentex dentex larvae at the Artemia feeding stage

This study was designed to investigate the requirements of Dentex dentex larvae for (n-3) highly unsaturated fatty acids (HUFA) at the Artemia feeding stage. Artemia were enriched using mixtures of ICES Experimental Emulsions ICES 50/0.6/C (500 mg/g (n-3) HUFA, 0.6 DHA/EPA ratio, based on ethyl esters) and ICES 0/-/C (based on coconut oil) and to give five dietary treatments which contained different levels of (n-3) HUFA from 0.72 to 6.23 as dry weight percentage. Optimal growth, as evidenced by total length, individual dry weight, specific growth rate and thermal growth coefficient, was achieved when dietary (n-3) HUFA was 3.97 on a dry weight basis. Larvae fed Artemia enriched with apparently super-optimal levels of (n-3) HUFA (5.67-6.23 %) showed significantly lower vitamin E contents and higher malondialdehyde (MDA) levels combined with their eyes having maximum (n-3) HUFA values and DHA/EPA ratios. Poorer performance of larvae was associated with increased dietary and larval MDA and decreased larval vitamin E, indicating increasing oxidation of (n-3) HUFA in Artemia and larval utilization of vitamin E with increasing levels of dietary (n-3) HUFA, particularly at supraoptimal levels of enrichment. The activities of antioxidant enzymes in the larvae was generally not greatly affected by the dietary treatments in this study. A balance is required between growth-promoting essential fatty acid (EFA) qualities of (n-3) HUFA and their potentially growth-inhibiting (prooxidant) qualities which must be counter-balanced with adequate dietary antioxidants

Comparación de diferentes estrategias de marcaje: Efectos en la tasa de retención, tasa de mortalidad y crecimiento de marcas alojadas en juveniles de corvina Argyrosomus regius (Pisces: Sciaenidae) criados en cautividad

The objective of this study was to compare the effectiveness of different tags (T-bar anchor tags, internal anchor tags and visible implant elastomers) implanted into juvenile meagre, Argyrosomus regius (Asso, 1801) for a restocking programme conducted in the Balearic Islands. Effectiveness was assessed in terms of tag loss, fish survival and fish growth by means of a tank experiment. The internal anchor tags showed the highest retention rate (100%), but the tagging mortality was also high (40%). The tagging mortality of T-bar tags was negligible. However, another tank experiment with different food rates showed the tag retention rate of the T-bar tag to be highly variable, ranging from 35% to 95%. In contrast with other reported results, the retention rate of visible implant elastomers was low (48%). Finally, none of the tested tags affected growth. In summary, the T-bar anchor tags showed the best trade-off between short-term tag retention and fish mortality, and seem to be the most suitable tagging method for meagre juveniles.El objetivo de este estudio fue comparar la efectividad de diferentes marcas (marca con anclaje en T, marca con anclaje abdominal y marcaje con elastómero visible, VIE) implantadas en corvinas juveniles (Argyrosomus regius Asso, 1801) para un programa de repoblación llevado a cabo en las Islas Baleares. La efectividad fue evaluada en función de la pérdida de marcas, la supervivencia y el crecimiento de los peces mediante un experimento en tanque. Las marcas con anclaje abdominal presentaron la tasa de retención más alta (100%), pero también presentaron la mayor tasa de mortalidad (40%). La tasa de mortalidad de las marcas con anclaje en T fue despreciable. Sin embargo, otro experimento con diferentes tasas de alimentación mostró que la tasa de retención de las marcas T fue muy variable, oscilando entre un 35% y un 95%. En contraste con otros resultados publicados, la tasa de retención de los VIE fue baja (48%). Finalmente, ninguna de las marcas testadas afectó al crecimiento. En resumen, las marcas con anclaje en T mostraron el mejor compromiso entre la tasa de retención a corto plazo y la tasa de mortalidad de los peces, y parece ser el método de marcaje más adecuado para los juveniles de corvina