Entity

Time filter

Source Type


Rodrigo M.A.,University of Valencia | Rojo C.,University of Valencia | Segura M.,University of Valencia | Alonso-Guillen J.L.,University of Valencia | And 2 more authors.
Aquatic Botany | Year: 2015

A small, shallow basin was created and flooded with groundwater in a Reserve Area in Albufera de València Natural Park (AVNP) under the scope of a restoration program intended to mimic typical environments such as freshwater springs, abundant in the past but currently suffering from deterioration (desiccation, pollution, etc.), with the ultimate goal of increasing local biodiversity of submerged macrophytes, particularly charophytes. In this study we have monitored, from April 2009 (a few months after its first flooding) to September 2012, the dynamics of charophyte growth and related physical, chemical and biotic variables to highlight the factors determining charophyte success. Just after flooding, five charophyte species grew spontaneously when oospores germinated in the sediments. Chara hispida populations largely dominated the community and developed dense meadows that covered virtually the entire pond floor. Charophytes exerted a negative influence on phytoplankton densities, increasing water transparency. C. hispida stands precipitated substantial CaCO3 in the form of incrustations on the plants, accompanied by coprecipitation of inorganic phosphorus, maintaining low concentrations of soluble P in the water. Reduced groundwater inflow, increased salinity, nutrient concentration, turbidity and augmented feeding pressure by waterfowl, separately or by synergistic effects, considerably reduced charophyte development during the final year of the study; however, charophytes still represent one of the most extensive and dense stands of submerged vegetation within AVNP, verifying the achievement of the goal of the restoration plan. The knowledge obtained has allowed us to recommend several measures to counteract the decrease of charophytes, which can also be applied in other regions affected by the same stressors. © 2014 Elsevier B.V. Source


Rodrigo M.A.,University of Valencia | Rojo C.,University of Valencia | Alonso-Guillen J.L.,University of Valencia | Vera P.,Sociedad Espanola de Ornitologia SEO BirdLife
Ecological Engineering | Year: 2013

Two small, shallow lagoons newly created from former rice fields in the Mediterranean coast (Albufera de València Natural Park, Spain) were restored by planting several species of submerged macrophytes (Myriophyllum spicatum, Ceratophyllum demersum, Potamogeton spp., Zannichellia peltata and Ranunculus peltatus) in 2008. Charophytes also appeared spontaneously. M. spicatum was the species that dominated both lagoons and almost completely covered their surface. M. spicatum reached a high biomass and displayed a seasonal pattern, declining during the cold season and reappearing in the spring. No submerged vegetation was observed in the lagoons from 2011 onward. The major purpose of the present study was to elucidate the factors that caused the total disappearance and prevented the regeneration of submerged vegetation cover in both lagoons. Such factors may include negative biotic relationships such as those related to the presence of fish and crayfish, waterfowl grazing, phytoplankton and epiphytic development that causes shading and abiotic factors such as water nutrient concentration. Three different types (treatments) of 1-m2 exclosures were set up and planted with macrophyte cultures that formed 3 different assemblages: Chara hispida alone, a mixture of C. vulgaris, C. baltica and Nitella hyalina and a mixture of higher plants (M. spicatum, C. demersum and Potamogeton pectinatus). The " Open" type of exclosure permitted the entrance of fish, crayfish, and birds. The " Lateral" exclosure prevented the entry of fish. The " Closed" exclosure also prevented bird grazing. To determine the potential of the seed sediment bank to regenerate submerged vegetation, we investigated lagoon sediments (i) to quantify seeds and (ii) to examine seed germination. The results indicate that there is not a sufficiently large reservoir of phanerogam seeds in the lagoon sediments to recover vegetation by germination. The " Closed" exclosures allowed the growth of all species in spite of the intense development of periphyton on macrophyte tissues and filamentous algae, which reduced light availability by up to 45%. The " Lateral" exclosures had a lower development of macrophytes. In the " Open" exclosures, almost no macrophytes were detected 3 weeks after planting. Water chemistry (P and N content) did not limit the development of the tested macrophyte species but did appear to negatively affect charophytes in one of the lagoons. The deleterious effect of exotic fauna (particularly carps and crayfish) in combination with the high herbivory pressure by waterfowl, primarily during the periods when the rice fields surrounding the lagoons were dry, were the major factors that acted in a negative synergistic manner to prevent the recolonisation of the vegetation currently in the lagoons. A procedure to eradicate exotic fish and crayfish is required prior to any type of restoration effort involving the plantation of submerged macrophytes. More areas with permanent submerged vegetation in the Natural Park are required to decrease herbivory pressure. © 2013 Elsevier B.V. Source


Meier R.E.,UK National Oceanography Center | Wynn R.B.,UK National Oceanography Center | Votier S.C.,University of Exeter | McMinn Grive M.,Balearic Shearwater Conservation Association | And 10 more authors.
Biological Conservation | Year: 2015

Unprecedented changes to the marine environment and growth of bio-logging science make detailed study of the movement ecology of threatened marine species timely. Here, we study spatial and temporal patterns of marine space use by a critically endangered seabird: the Balearic shearwater Puffinus mauretanicus. Using a suite of bio-logging systems, 67 foraging trips were recorded during incubation periods between 2011 and 2014 from one of the species' largest colonies (Sa Cella, Mallorca). Most birds followed narrow flight corridors to restricted neritic foraging grounds on the Iberian continental shelf. Productive foraging areas along the Catalan coast (NE Spain) were consistent across multiple years and between sexes, indicating extensive use of predictable resources. While our study emphasises the vulnerability of this species to anthropogenic activity in nearshore waters, consistent commuting corridors and foraging grounds represent tractable habitat for protection and offer hope for developing area-based management approaches. Preferred foraging areas showed strong overlap with recently declared Special Protection Areas, strengthening the evidence base for targeted management at these sites. © 2015 The Authors. Source


Garcia-Tarrason M.,University of Barcelona | Becares J.,Sociedad Espanola de Ornitologia SEO BirdLife | Bateman S.,University of Barcelona | Arcos J.M.,Sociedad Espanola de Ornitologia SEO BirdLife | And 2 more authors.
Ecology and Evolution | Year: 2015

Some seabird species have learnt to efficiently exploit fishing discards from trawling activities. However, a discard ban has been proposed as necessary in Europe to ensure the sustainability of the seas. It is of crucial importance for the management and conservation purposes to study the potential consequences of a discard ban on the foraging ecology of threatened seabirds. We assessed the influence of fishing activities on the feeding habits of 22 male and 15 female Audouin's gulls (Larus audouinii) from the Ebro Delta (Mediterranean Sea) during the breeding period using GPS loggers together with Stable Isotope Analysis (SIA), which provided new insights into their foraging behavior and trophic ecology, respectively. GPS data revealed different sex-specific foraging patterns between workdays and weekends. Females were highly consistent in that they foraged at sea throughout the week even though discarding stops at weekends. In contrast, males switched from foraging at sea during the week (when discards are produced) to an increased use of rice field habitats at weekends (when fishermen do not work). This sex-specific foraging behavior could be related to specific nutritional requirements associated with previous egg production, an energetically demanding period for females. However, on a broader time scale integrated by the SIA, both sexes showed a high degree of individual specialization in their trophic ecology. The need to obtain detailed information on the dependence and response of seabirds to fishing activities is crucial in conservation sciences. In this regard, sex-specific foraging behavior in relation to fisheries has been overlooked, despite the ecological and conservation implications. For instance, this situation may lead to sex differentiation in bycatch mortality in longlines when trawlers do not operate. Moreover, any new fisheries policy will need to be implemented gradually to facilitate the adaptation of a specialized species to a discard ban scenario. © 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Source


Ramos R.,ISPA University | Ramos R.,University of Barcelona | Granadeiro J.P.,University of Lisbon | Rodriguez B.,Sociedad Espanola de Ornitologia SEO BirdLife | And 9 more authors.
Diversity and Distributions | Year: 2013

Aim: Apical pelagic species forage in predictable habitats, and their movements should signal biologically and ecologically significant areas of the marine ecosystem. Several countries are now engaged in identifying these areas based on animal tracking, but this is often limited to a few individuals from one breeding population, which may result in biased portrayals of the key marine habitats. To help identify such foraging areas, we compiled tracking data of a marine top predator from the main breeding colonies in the Central Macaronesia. Location: North-east Atlantic Ocean. Methods: Over seven years, we tracked the foraging movements of Cory's shearwaters (Calonectris borealis) from several populations during the chick-rearing period using global positioning system and platform terminal transmitter devices. Results: We obtained foraging trips from 174 shearwaters breeding on six important colonies representative of the range occupied in the Macaronesian Archipelagos of Madeira, Salvages and Canaries. Our results show that birds orient and move rapidly towards the closest neritic waters over the African continental shelf. Birds from different colonies show substantial spatial segregation in their foraging grounds but consistently overlap in some specific foraging areas along the Canary Current characterized by high productivity. By weighting the use of foraging grounds according to the size of each study population, we inferred the overall exploitation of such areas. Main conclusions: Our meta-population approach provides a more comprehensive picture of space use from both perspectives: the studied species and the Canary Current system. Foraging grounds consistently used by several populations may not be adequately identified by tracking a single population, and therefore, multiple population tracking studies are needed to properly delineate key conservation areas and inform conservation planning in the marine ecosystem. Finally, we highlight the long-term stability and sustainability of identified foraging areas and propose that countries with geographical jurisdictions over the Canary Current area should work towards multilateral agreements to set management plans for this key marine ecosystem. © 2013 John Wiley & Sons Ltd. Source

Discover hidden collaborations