Effect of complexation by natural phytoplankton exudates on the accumulation of cadmium and copper by the haptophyceae Cricosphaera elongata

The accumulation of cadmium and copper by Cricosphaera elongata is determined in the absence and presence of natural phytoplankton exudates. The concentrations of metals accumulated increase with increasing concentrations of metals in the medium. Organic substances liberated into the culture medium by C. elongata are able to decrease the amounts of metals taken up.     

The possible origin of Zostera noltii in the Canary Islands and guidelines for restoration

Seagrasses and their habitat are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly by anthropogenic disturbance, to three small surviving patches in a single harbor in Lanzarote. A previous genetic study, using neutral microsatellite markers, revealed that these patches consist of a single clonal individual. Here, an assignment test, using microsatellite data, was used to locate the most likely population of origin from a set of possible donor populations. Our results show that the Moulay Bousselham population in northern Morocco is assigned as the most likely population of origin (88%), although the probability of being at one generation time distance is low (2.7%). This result, however, allows locating the most closely related stands that may be the most successful donor populations for future restoration based on shoot or seed transplantation.     

Actions of 17β-estradiol on carbohydrate metabolism in liver,gills, and brain of gilthead sea bream Sparus auratus during acclimation to different salinities

The influence of gonadal maturation on seawater adaptability at the metabolic level was assessed in the euryhaline teleost Sparus auratus by treatment of immature fish with 17ß-estradiol (E₂) followed by acclimation to different environmental salinities. Fish were injected with coconut oil alone (sham) or containing E₂ (10 µg g^–1 body weight) and maintained in seawater (40). After 5 days, fish from oil- and E₂-implanted groups were sampled. At the same time, fish of both groups were transferred to brackish water (5, hypoosmotic test), seawater (40, transfer test), and hypersaline water (55, hyperosmotic test); 4 days after transfer (9 days post-implant) all groups were sampled. Data obtained from liver suggest that E₂ treatment produced effects comparable to those already reported in literature, including decreased glycogen levels, increased glycolytic potential, and decreased gluconeogenic potential. This, together with the fact that many changes displayed in shams among salinities disappeared in E₂-treated fish allow us to suggest that the response of liver carbohydrate metabolism to osmotic acclimation is exceeded by the response elicited by E₂ treatment. In gills, E₂ treatment produced increased lactate levels, decreased capacity for use of exogenous glucose, and decreased the potential of the pentose phosphate pathway. These findings suggest that the energy demand occurring in gills during osmotic acclimation should be increasingly fuelled by substrates other than exogenous glucose. Finally, data obtained in brain of E₂-treated fish suggest a lower necessity of exogenous glucose, increased lactate levels, and decreased glycolytic potential.Communicated by S.A. Poulet, Roscoff     

Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming

Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTI_SD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTI_SD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTI_SD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.     

Adenylate cyclase of Mytilus galloprovincialis posterior adductor muscle: basal properties and sensitivity to serotonin

The presence and characteristics of a membrane-bound adenylate cyclase from Mytilus galloprovincialis Lmk posterior adductor muscle have been investigated. The enzyme has a Michaelis constant (K _m) of 0.38 mM at 20°C and requires divalent cations (Mg²⁺/Mn²⁺) for its activity. Optimal GTP concentrations are between 10^-5 and 10^-4 M. The non-hydrolizable GTP-analogues GMPpNHp and GTPS increase the activity of the enzyme four- to ten-fold. Sodium fluoride stimulates the enzymatic activity seven- to eight-fold. Forskolin increases the enzymatic activity two- to three-fold. Serotonin stimulates the adenylate cyclase activity in a dose-dependent manner. These experiments were performed with mussels collected from the estuary of Muros, Spain, in 1990.     

Effects of Amazonian flying rivers on frog biodiversity and populations in the Atlantic rainforest

Given the speed at which humans are changing the climate, species with high degrees of endemism may not have time to avoid extinction through adaptation. We investigated through teleconnection analysis the origin of rainfall that determines the phylogenetic diversity of rainforest frogs and the effects of microclimate differences in shaping the morphological traits of isolated populations (which contribute to greater phylogenetic diversity and speciation). We also investigated through teleconnection analysis how deforestation in Amazonia can affect ecosystem services that are fundamental to maintaining the climate of the Atlantic rainforest biodiversity hotspot. Seasonal winds known as flying rivers carry water vapor from Amazonia to the Atlantic Forest, and the breaking of this ecosystem service could lead Atlantic Forest species to population decline and extinction in the short term. Our results suggest that the selection of morphological traits that shape Atlantic Forest frog diversity and their population dynamics are influenced by the Amazonian flying rivers. Our results also suggest that the increases of temperature anomalies in the Atlantic Ocean due to global warming and in the Amazon forest due to deforestation are already breaking this cycle and threaten the biodiversity of the Atlantic Forest hotspot.     

Amino acid metabolism and protein turnover in larval turbot (Scophthalmus maximus) fed natural zooplankton or Artemia

The present paper studied the influence of different food regimes on the free amino acid (FAA) pool, the rate of protein turnover, the flux of amino acids, and their relation to growth of larval turbot (Scophthalmus maximus L.) from first feeding until metamorphosis. The amino acid profile of protein was stable during the larval period although some small, but significant, differences were found. Turbot larvae had proteins which were rich in leucine and aspartate, and poor in glutamate, suggesting a high leucine requirement. The profile of the FAA pool was highly variable and quite different from the amino acid profile in protein. The proportion of essential FAA decreased with development. High contents of free tyrosine and phenylalanine were found on Day 3, while free taurine was present at high levels throughout the experimental period. Larval growth rates were positively correlated with taurine levels, suggesting a dietary dependency for taurine and/or sulphur amino acids. Reduced growth rates in Artemia-fed larvae were associated with lower levels of free methionine, indicating that this diet is deficient in methionine for turbot larvae. Leucine might also be limiting turbot growth as the different diet organisms had lower levels of this amino acid in the free pool than was found in the larval protein. A previously presented model was used to describe the flux of amino acids in growing turbot larvae. The FAA pool was found to be small and variable. It was estimated that the daily dietary amino acid intake might be up to ten times the larval FAA pool. In addition, protein synthesis and protein degradation might daily remove and return, respectively, the equivalent of up to 20 and 10 times the size of the FAA pool. In an early phase (Day 11) high growth rates were associated with a relatively low protein turnover, while at a later stage (Day 17), a much higher turnover was observed. Received: 19 March 1997 / Accepted: 14 April 1997     

Development of plant-friendly vermicompost using novel biotechnological methods

Journal of Material Cycles and Waste Management - For the first time in the world, raw tea waste from tea plants was mineralized by rapid biotechnological methods using beneficial worms, enzymes...     

Vegetation cover and rainfall seasonality impact nutrient loss via runoff and erosion in the Colombian Andes

Regional Environmental Change - Mountain ecosystems provide key services to a large portion of the population in the tropics. However, they are particularly vulnerable to regional environmental...     

A management system for end-of-life tyres: a Portuguese case study

The European Union introduced several policy instruments based in the extended producer responsibility (EPR) in order to improve the environmental performance of products and services through their life cycles. In this context, the Portuguese government decided to apply the EPR concept to tyres, and producers were obliged to constitute an end-of-life management system to promote the collection, recycling and reuse of end-of-life (EOL) tyres. This required producers, distributors, recyclers and retreaders to be identified and characterized, and local processing infrastructures to be analyzed. The information was used to design an economically optimised EOL tyre management system while promoting the activity of all EOL operators in order for the imposed collecting and recovery targets to be fulfilled. This paper discusses the interaction between the different governmental, private and academic institutions for the creation of the integrated management system for EOL tyres, the approach taken, the technical, political and legal aspects underneath them, as well as the environmental consequences induced by the creation of the management system. The results obtained during the first years of operation are reported and show an increase in the collection and recycling of EOL tyres and the consolidation of the collection and processing infrastructures.