Geographic patterns of natal dispersal in barn swallows <Emphasis Type="Italic">Hirundo rustica</Emphasis> from Denmark and Spain

Dispersal is an important factor that determines the degree of gene flow and, hence, the degree of differentiation among populations. Using two long-term datasets on natal philopatry and short-distance dispersal in barn swallows Hirundo rustica from Denmark and Spain, we evaluated the fitness costs and benefits and test a number of predictions about the functional significance of dispersal. The proportion of philopatric individuals was more than six times larger in Spain than in Denmark, with a higher rate of philopatry in males than in females. Dispersal propensity decreased in both populations during the course of the study. Males from the more philopatric Spanish population lived longer when philopatric rather than dispersing while that was not the case for either sex of the less philopatric Danish population. There were large differences in dispersal propensity among cohorts and breeding sites, suggesting that sites differed in their suitability as sites for immigrants. We found no evidence consistent with the mate competition hypothesis suggesting that males in better condition or with larger condition-dependent secondary sexual characters were more likely to be philopatric. These findings suggest that there is a high degree of intraspecific variation in dispersal propensity between populations, probably relating to local differences in costs and benefits of philopatry and dispersal.     

Evaluation of porous cup soil‐water samplers under laboratory conditions: Comparison of ceramic and PTFE cups

Three different types of soil solution samplers (two ceramic cups and PTFE) were tested in the laboratory to validate their use for collecting soil‐water samples and for monitoring the chemical composition of soil solutions. Interactions between porous materials and chemical solutions were examined under different experimental conditions for several major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺) and anions (HCO^‐ ₃, NO^‐ ₃, SO₄ ^2‐ and Cl^‐) and for several minor ions (NH⁺ ₄, NO^‐ ₄, PO₄ ^3‐and B).

The results show that ceramic cups are not inert for bicarbonate, calcium and phosphate ions. Their use is only valid for a limited number of ions such as chloride and nitrate which, however, are the most studied ions in field experiments. PTFE cups have less restrictions although their use in measuring sulphates, phosphates and ammonium presents some problems.

Choosing the appropriate type of cup depends on the objectives. In any case, laboratory experiments must be performed before installation.     

EROD activity and stable isotopes in seabirds to disentangle marine food web contamination after the Prestige oil spill

In this study, we measured via surgical sampling hepatic EROD activity in yellow-legged gulls from oiled and unoiled colonies, 17 months after the Prestige oil spill. We also analyzed stable isotope composition in feathers of the biopsied gulls, in an attempt to monitor oil incorporation into marine food web. We found that yellow-legged gulls in oiled colonies were being exposed to remnant oil as shown by hepatic EROD activity levels. EROD activity was related to feeding habits of individual gulls with apparent consequences on delayed lethality. Capture-recapture analysis of biopsied gulls suggests that the surgery technique did not affect gull survival, giving support to this technique as a monitoring tool for oil exposure assessment. Our study highlights the combination of different veterinary, toxicological and ecological methodologies as a useful approach for the monitoring of exposure to remnant oil after a large oil spill.     

Performance of <Emphasis Type="Italic">Eleocharis macrostachya</Emphasis> and its importance for arsenic retention in constructed wetlands

Introduction  

Arsenic (As) can be removed from water via rhizofiltration using phytostabilizing plants. The aim of this study was to investigate the performance of Eleocharis macrostachya in constructed wetland prototypes, as well as the plant's arsenic mass retention and the distribution of As along the wetland flow gradient and the soil in the wetland mesocosmos.     

Diversity and community structure of culturable arsenic-resistant bacteria across a soil arsenic gradient at an abandoned tungsten-tin mining area

We studied the bacterial diversity at a single location (the Terrubias mine; Salamanca province, Spain) with a gradient of soil As contamination to test if increasing levels of As would (1) change the preponderant groups of arsenic-resistant bacteria and (2) increase the tolerance thresholds to arsenite [As(III)] and arsenate [As(V)] of such bacteria. We studied the genetic and taxonomic diversity of culturable arsenic-resistant bacteria by PCR fingerprinting techniques and 16S rRNA gene sequencing. Then, the tolerance thresholds to As(III) and As(V) were determined for representative strains and mathematically analyzed to determine relationships between tolerances to As(III) and As(V), as well as these tolerances with the soil contamination level. The diversity of the bacterial community was, as expected, inversely related to the soil As content. The overall preponderant arsenic-resistant bacteria were Firmicutes (mainly Bacillus spp.) followed by γ-Proteobacteria (mainly Pseudomonas spp.), with increasing relative frequencies of the former as the soil arsenic concentration increased. Moreover, a strain of the species Rahnella aquatilis (γ-Proteobacteria class) exhibited strong endurance to arsenic, being described for the first time in literature such a phenotype within this bacterial species. Tolerances of the isolates to As(III) and As(V) were correlated but not with their origin (soil contamination level). Most of the strains (64%) showed relatively low tolerances to As(III) and As(V), but the second most numerous group of isolates (19%) showed increased tolerance to As(III) rather than to As(V), even though the As(V) anion is the prevalent arsenic species in soil solution at this location. To our knowledge, this is the first study to report a shift towards preponderance of Gram-positive bacteria (Firmicutes) related to high concentrations of soil arsenic. It was also shown that, under aerobic conditions, strains with relatively enhanced tolerance to As(III) predominated over the most As(V)-tolerant ones.     

Socio-economic vulnerability to climate change in the central mountainous region of eastern Mexico

Climate change effects are expected to be more severe for some segments of society than others. In Mexico, climate variability associated with climate change has important socio-economic and environmental impacts. From the central mountainous region of eastern Veracruz, Mexico, we analyzed data of total annual precipitation and mean annual temperature from 26 meteorological stations (1922–2008) and from General Circulation Models. We developed climate change scenarios based on the observed trends with projections to 2025, 2050, 2075, and 2100, finding considerable local climate changes with reductions in precipitation of over 700 mm and increases in temperature of ~9°C for the year 2100. Deforested areas located at windward were considered more vulnerable, representing potential risk for natural environments, local communities, and the main crops cultivated (sugarcane, coffee, and corn). Socio-economic vulnerability is exacerbated in areas where temperature increases and precipitation decreases.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0690-4) contains supplementary material, which is available to authorized users.     

Effect of the pesticide lindane on the biomass of the microalgae Nannochloris oculata

This study assesses the growth of the microalgae Nannochloris oculata in the presence of lindane and the ability of N. oculata to remove lindane from media. Algal biomass increased with 0.1 and 0.5 mg L^?1 of lindane, and lindane concentrations in the media decreased. N. oculata removed 73% and 68.2% of lindane in the 0.1 and 0.5 mg L^?1 media concentrations, respectively. Algal biomass decreased to the level of the control at lindane concentrations greater than 2.5 mg L^?1, probably due to toxicity. N. oculata removed lindane from the media at concentrations lower than 1.0 mg L^?1. Thus, N. oculata may be useful for lindane bioremediation in contaminated aquatic systems.     

Integrative assessment of coastal pollution in a Ría coastal system (Galicia, NW Spain): correspondence between sediment chemistry and toxicity

Elutriate embryo-larval bioassays with sea-urchins (Paracentrotus lividus) and ascidians (Ciona intestinalis) were conducted concurrently with trace metal analyses as part of an integrative assessment of sediment pollution at Ría de Pontevedra (Galicia, NW Spain). High metal contents in sediments were found in localised areas from the inner part of the estuary indicating a clear anthropogenic influence. In particular, very high Cu, Zn and Pb levels were found at sites P2 and P3, which were also the most toxic to the embryo-larval bioassays. Sediment quality guidelines were used to help in the ecological interpretation of sediment chemistry data and to identify pollutants of concern. Cu and Zn in P3 were consistently above the effects range median (ERM) values, which seem to be good predictors of toxicity to sea-urchin and ascidian embryos. A toxic unit approach, based on published EC(50) values and metal levels in elutriates, was used to assess the harmful ecological effects associated to sediment chemistry. Toxicity detected in P3 may be explained on the basis of the toxic unit model; however, the high toxicity detected at P2 may be attributable not only to the metals quantified in the analyses but also to unmeasured organic pollutants. Multidimensional scaling applied independently to the toxicology and chemistry data resulted in a good agreement between both types of configurations. Moreover, the Mantel test revealed a significant correlation (r(M)=0.481; p=0.019) between metal concentrations and toxicity data profiles, supporting the correspondence between configurations.     

Effects of cold-dark storage on growth of Cylindrotheca closterium and its sensitivity to copper

Cylindrotheca closterium cells were maintained at low temperature (4+/-1 degrees C) and dark conditions up to 21 weeks to assess the effect on survival and physiological status. From a control culture under standard conditions, three densities were prepared: (A) 2 x 10(4), (B) 10 x 10(4), and (C) 25 x 10(4) cells ml(-1). Weekly, inoculums of each stored density were exposed to continuous light and at 20+/-1 degrees C. Sensitivity to copper for microalgal cultures was evaluated in order to assess possible changes in cells sensitivity due to storage. Concurrently, assays with a control culture were carried out in order to assess the sensitivity of C. closterium to copper and to be able to generate a standard sensitivity control chart with a mean value of EC50-72 h+/-2SD (standard deviation). Density-C presented higher cell yield values, between 40% and 80% relative to control culture. Cell density showed to be important feature that may be taken into account in cell storage experiments. There was an increase in sensitivity of cells submitted to storage; however results always kept in the range established as standard sensitivity with no statistically significant difference with regards to control culture. EC50-72 h mean value for the control culture was 29+/-10 mug Cul(-1), while for densities-A, B and C were 22+/-7; 23+/-9 and 23+/-8 microg Cul(-1), respectively. In spite of drastic changes in the environmental conditions due to storage, it is concluded that C. closterium cells stored during 5 months remained metabolically active and with no significant change in its sensitivity.     

Temperature enhanced effects of chlorine exposure on the health status of the sentinel organism Mytilus galloprovincialis

It now is widely recognised that the global temperature is rising, a phenomenon which could alter the effects of pollution on wildlife. In order to assess the role of temperature and exposure to chlorine due to cooling water discharges, a battery of metabolic, oxidative stress and histological parameters were evaluated in Mytilus galloprovincialis after 15 and 30 days at 15 °C and at two increased temperatures (+5 and +10 °C). Diverse gill pathologies such as haemolymphatic sinus dilatation, an increased number of mucocytes and granulocytes as well as a lower number of cilia were observed after 30 days exposure at higher temperatures. Protein, amino acid, triglyceride and fatty acid levels decreased when the temperature increased, as a consequence of higher energetic demand. Similarly, acetylcholinesterase, catalase and glutathione S-transferase activities showed an inhibition at higher temperatures, although gill lipid peroxidation levels remained unaffected. Our results suggest that increased temperatures induce deterioration in the health status of the mussels and in their defensive capacity against a polluted environment.