Movimientos verticales diarios de larvas de peces en estadío pre-flexión asociados a las praderas de Posidonia oceanica

Habitat complexity is a strong determinant of fish assemblage structure. Enhanced food resources and protection from predators are generally considered the main benefits of vegetated areas. We investigated the diel and vertical movements of preflexion fish larvae within and above the leaf canopy of Posidonia oceanica to determine if it acts as an important habitat for larval stage fish. Samples were taken with moored plankton nets during the night and day at two depths (13 and 15 m) over five consecutive days in July 2000 in the Marine Protected Area off Tabarca Island (Spain, SW Mediterranean Sea). In total, 353 fish larvae were captured. The most abundant taxa were Sardinella aurita, Sparidae, Engraulis encrasicolus and Gobiidae. Sparidae were more abundant within the leaf canopy during the day but increased in waters 2 m above the canopy at night. In contrast, Sardinella aurita were present throughout the entire water column during both the day and night. We conclude that the P. oceanica leaf canopy is important as a transitional shelter for the early stage larvae of some demersal fish species.El tipo de hábitat determina la estructura del poblamiento larvario de peces. Los principales beneficios que proporciona un hábitat con vegetación son el incremento de las fuentes de alimento y una mayor protección frente a los predadores. Este estudio se ha centrado en praderas de Posidonia oceanica para evaluar su papel como zonas de refugio, función que ha sido poco estudiada. Este trabajo se ha llevado a cabo en la Reserva Marina de Tabarca (España, SW Mar Mediterráneo). Las muestras se recolectaron con redes de plancton fijas en periodos diurnos y nocturnos, y a dos profundidades (13 y 15 m), durante 5 días consecutivos en el mes de Julio de 2000. Se capturaron 353 larvas y 256 fueron identificadas. Los taxones más abundantes fueron S. aurita, Sparidae, Engraulis encrasicolus y Gobiidae. Sparidae dominó al nivel de las hojas de la pradera durante el día, incrementando su presencia en la columna de agua durante la noche; mientras que la S. aurita se encontró a lo largo de toda la columna de agua en los dos periodos estudiados. Nuestro estudio confirma el papel de las praderas de P. oceanica como zona de refugio transitoria para los primeros estadios de larvas de de peces, aunque limitado a algunas especies demersales.

Low satisfaction and failed relational coordination among relevant stakeholders in Spanish Mediterranean marine protected areas

Marine protected areas (MPAs) are a conservation tool that are increasingly commonplace around the world. MPAs have the potential to benefit both ecosystems and human communities if well-designed and implemented. Achieving effective implementation and governance of MPAs, however, is complicated because they deal with systems that overlap with both non-human environments and human economies and societies. As a result, MPA success is thought to be primarily dependent on socioeconomic factors, particularly the behavior of stakeholder groups involved in the MPAs. Using the theory of relational coordination, we designed surveys that we delivered to members of four stakeholder groups implicated in five MPAs in the Spanish Mediterranean to investigate their habits of inter- and intra-group communication and relations. Relational coordination posits that high-quality communication and relations results in positive stakeholder behaviors and an effective system, which makes it a useful tool to investigate the effectiveness of the MPAs involved in this study. Our results demonstrate that a high degree of relational coordination leads to higher satisfaction on the part of the participants in the system. The exploratory model constructed here also supports the notion that each stakeholder group adopts particular beliefs and behaves in particular ways in terms of relational coordination and satisfaction. We found patterns that indicated poor communication and relations amongst the four stakeholder groups, which in turn has grave implications for management outcomes of these MPAs. Cumulatively, these conditions could precipitate management failure. To remedy these concerns, we recommend establishing channels of communication between the four stakeholder groups, and investigating means to cultivate good relations amongst these groups. Doing so will help assure management success

Habitat colonisation by amphipods : comparison between native and alien algae

Invasion of algal habitat by the alien alga Caulerpa racemosa results in changes to habitat structure, part of which may be due to accumulation of large amounts of detritus. In turn, such changes lead to alterations in the assemblage structure of associated invertebrates. The present study was aimed at testing the hypotheses that (i) invasion by C. racemosa will influence the assemblage structure of amphipods associated with vegetated habitats, since colonisation by the invertebrates will differ between native algal habitat and habitat invaded by the alien alga, and (ii) differences in colonisation are mainly due to accumulation of detritus by the alien alga. To test these hypotheses, field experiments on habitat colonisation were undertaken at two sites within each of two Mediterranean localities (Malta and Spain). Using mesh bags, 3 different habitats were introduced at each site: habitat with the native alga Halopteris scoparia, habitat with C. racemosa, and an artificial habitat resembling algal habitat. Additionally, empty mesh bags were deployed as controls. Mesh bags containing plant material were defaunated prior to deployment. For each of the three habitat types, three supplement treatments were used: (i) no detritus, (ii) low detritus, and (ii) high detritus. The bags were placed on a rocky substratum at a water depth of 4.5–5 m for a period of 14 days, after which they were collected and the amphipod assemblage was assessed. The results showed that, overall, amphipod species richness and abundance were higher in bags containing H. scoparia but some amphipods exhibited a broad capability to colonize new habitat such as C. racemosa. Accumulation of detritus by the alien alga may play an important role but small-scale physical or biological habitat features can affect its ecological role.peer-reviewe

An Ecosystem Approach to the Role of Fish Farming in Coastal Areas

Coastal ecosystems put up most of the impacts from human activities in the sea. Generally, assessment based on a unispecific ecological group and/or habitat reflects only a fraction of what is happening in the ecosystem, and usually it is biased by the spatial and temporal variability at small scales. This is more evident when several human activities co-exist in the same area and interact synergically among them and with the natural structure and dynamics of the ecosystem. An ecosystemic assessment can combine several ecological groups, habitats, processes and/or activities, and offer a more holistic picture about the structure and dynamics of the considered coastal area.This study was partially funded by Spanish Ministry of Science Grant (Project FATFISH CTM2009-14362-C02-01). JTBS thanks to Conselleria d'Educació, Generalitat Valenciana, for financing the visit to La Paz during 2012. FAS thanks support to visit the University of Alicante during 2013

Seasonal patterns and diets of wild fish assemblages associated with Mediterranean coastal fish farms

Fish are attracted to floating structures, including coastal cage fish farms, sometimes in dense aggregations. To understand better the influence of aquaculture on wild fish stocks, we carried out seasonal visual censuses around three southwestern Mediterranean farms over 2 years to assess the temporal patterns of the aggregated fish assemblage. In addition, we analysed the diet of the five most abundant species. Aggregations around all farms were large throughout the year, although species composition and abundance differed among farms and seasons. Fish farms are attractive habitats for certain species of wild fish in specific seasons. Adult fish of reproductive size dominated the assemblages, and stomach content analysis revealed that 66–89% of fish of the five most abundant taxa had consumed food pellets lost from the cages. We estimated that wild fish consume up to 10% of the pellets used at farms, indicating that food is a key attractant. Regional monitoring of farm-associated wild fish assemblages could aid management of the interaction of aquaculture and wild fish resources, because changes in feeding behaviour may have consequences for fish populations and local fisheries.The study forms part of the ACUFISH project (Unidad de Biología Marina, University of Alicante) and was funded by Spanish Ministry of Science grant MYCT-REN2003-00794

Fish assemblage of two Posidonia oceanica (L.) Delile, 1813, meadows with different degrees of conservation

Ictiofauna de dos praderas de Posidonia oceanica (L.) Delile con distinto grado de conservación

Coastal aquaculture and conservation can work together

Current fishing practices are regarded as unsustainable (Pauly et al. 2002), yet our appetite for seafood grows. To meet the growing gap, there are increasing calls for mankind to tame the oceans through aquaculture (Marra 2005). Close to the coast, rapid expansion of marine aquaculture is underway throughout the world. Sea cages enclose 2.5 million tons of fish, while 12 million tons of mussels, oysters and clams hang from floating ropes or grow on racks or trays (FAO 2004). Aquaculture structures are now ubiquitous to many coastlines. As the expansion continues, how can we best manage the interaction between natural communities and aquaculture

Formando investigadores a través de las prácticas docentes

El aprendizaje de la teoría, los métodos y técnicas utilizados en el proceso de investigación, requieren una visión global que en muchos casos el alumnado percibe como información aislada y dispersa entre las diferentes materias. Con el objeto de suplir esta carencia se han diseñado trabajos de investigación dirigidos, con el fin de iniciar a los alumnos y alumnas en su formación como investigadores, desde los primeros años del grado de Ciencias del Mar. Por ello, esta red pretende iniciar y afianzar las destrezas propias del método científico a través de prácticas docentes transversales, mediante la coordinación entre asignaturas complementarias y el trabajo en equipo. Este proceso de formación de los alumnos como investigadores, esta tutelado por una evaluación continua lo que sirve de retroalimentación del aprendizaje de cada uno de los pasos del proceso de investigación: planteamiento de hipótesis y objetivos, búsqueda de información, diseño experimental, interpretación de resultados y por último difusión de los mismos mediante informes o exposiciones públicas

Formando investigadores a través de las prácticas docentes II: Consolidación de la metodología docente ad hoc

Uno de objetivos principales de las redes de investigación en docencia universitaria es fomentar el seguimiento, la coordinación y el trabajo en equipo del profesorado para el desarrollo de metodologías que permitan responder a las necesidades formativas del alumnado. Con la finalidad de lograr este objetivo, se inició, en convocatorias previas, una red de investigación basada en la adecuación de los criterios de evaluación de las capacidades, competencias y habilidades adquiridas por el alumnado en su formación como investigadores y que permitiese la coordinación entre asignaturas complementarias a través de prácticas docentes enfocadas a un marco de transversalidad y formación integral. Tras la puesta en marcha de la red “Formando investigadores a través de prácticas docentes” y su posterior seguimiento se pretende consolidar la metodología aplicada en la evaluación del proceso de aprendizaje del alumnado en su formación como nuevos investigadores, así como la formación continua del profesorado en metodologías docentes innovadoras y transversales. Un objetivo colateral es la posibilidad de dotar de herramientas en la evaluación externa de la calidad docente mediante los resultados tangibles de esta red