Feeding ecology of the green turtle (Chelonia mydas) at rocky reefs in western South Atlantic

Feeding ecology of green turtles was investigated between January 2005 and April 2008 at Arvoredo Reserve, Brazil (27°17′S, 48°18′W). Data were obtained through the performance of observational sessions, geo-referenced counts, benthic surveys, capture and recapture of individuals, and oesophageal lavages. This protected area was identified as an important green turtle feeding ground, used year-round by juveniles (curved carapace length = 32–83 cm). Turtles fed close to the rocky shores of the area and selected grazing sites commonly at hard-to-reach, near-vertical portions of the rocks. They were less active in cold months, and more abundant at shallow areas of the reef (0–5 m), where their preferred food items occurred. Their diet was dominated by macroalgae species but invertebrates were also present. Their main food item was the red algae Pterocladiella capillacea, which seems to be eaten through periodical cropping of its tips. Observational methods such as the ones applied here could be incorporated to other research programs aiming to understand the relationships between Chelonia mydas feeding populations and their environment.     

Mating opportunities,paternity, and sexual conflict: paternal care in northern and southern temperate house wrens

Males are generally predicted to care less for their young when they have more additional mating opportunities, lower paternity, or when their mates care more. We tested these predictions using male provisioning as a proxy for paternal care in two temperate populations of house wrens (Troglodytes aedon) with divergent life histories. Males in the migratory, occasionally socially polygynous New York, USA (northern) population provisioned less when more local females were fertile. A similar relationship was only weakly supported in the resident, socially monogamous Buenos Aires Province, Argentina (southern) population, possibly due to the higher density of house wrens there. A relationship between male provisioning and level of paternity within the brood was supported in both populations, but in opposite directions: while males in the southern population provisioned less at broods containing more extra-pair young, males in the northern population provisioned such broods more, contradicting predictions. Males provisioned less when their mates provisioned more in both populations, in agreement with sexual conflict theory. Additionally, the populations both exhibited a positive relationship between male provisioning and nestling age, but differed in the direction of the relationships of male provisioning with date and brood size. Our results suggest that even within a species, life history differences may be accompanied by differences in the determinants of behavior such as paternal care.     

Parent–offspring dietary segregation of Cory’s shearwaters breeding in contrasting environments

In pelagic seabirds, who often explore distant food resources, information is usually scarce on the level of trophic segregation between parents and their offspring. To investigate this issue, we used GPS tracking, stable isotopes and dietary information of Cory’s shearwaters Calonectris diomedea breeding in contrasting environments. Foraging trips at Selvagem Grande (an oceanic island) mainly targeted the distant African coast, while at Berlenga island (located on the continental shelf), shearwaters foraged mainly over nearby shelf waters. The degree of isotopic segregation between adults and chicks, based on δ¹³C, differed markedly between the two sites, indicating that adult birds at Selvagem fed their chicks with a mixture of shelf and offshore pelagic prey but assimilated more prey captured on coastal shelf waters. Isotopic differences between age classes at Berlenga were much smaller and may have resulted from limited dietary segregation or from age-related metabolic differences. The diet of shearwaters was also very different between the two colonies, with offshore pelagic prey only being detected at Selvagem Grande. Our findings suggest that spatial foraging constraints influence resource partitioning between pelagic seabirds and their offspring and can lead to a parent–offspring dietary segregation.     

Assessing sustainable development in urban areas using cognitive mapping and MCDA

As interest in sustainability-related issues has increased over recent years, so too has urban sustainability risen to the fore, in academic, practitioner, and policymaking circles alike. Urban sustainability requires a balance between environmental concerns, the economy, and social development in urban areas. However, over the years, there has been an exponential increase in urban density, accompanied by increased economic activity and high levels of consumption, which have hindered urban planning and made the sustainable management of urban areas more difficult. It has therefore become increasingly necessary to combine the interests of the various stakeholders involved in – or affected by – urban planning measures, in order to achieve a balance between their needs, those of the environment and future generations, and the need for economic development. Sustainability evaluation models can in this sense be considered a baseline condition for sustainable development. However, most existing evaluation systems present limitations in terms of criteria identification and the calculation of the respective trade-offs. To address these issues, the current study aims to combine cognitive mapping and the Analytic Hierarchy Process (AHP) to prioritize the determinants of sustainable development in urban areas. The advantages and limitations of our proposal are also analyzed.     

Health risks of potentially toxic trace elements in urban soils of Manaus city,Amazon, Brazil

Environmental Geochemistry and Health - The city of Manaus is the biggest industrial city of the north Brazilian region, and a haphazard urbanization process characterizes it. The continuous...     

In Vitro Degradation and Cytotoxicity Response of Biobased Nanoparticles Prepared by Thiol-ene Polymerization in Miniemulsion

Journal of Polymers and the Environment - Biodegradability is a key feature for the application of polymeric devices in medicine. This study reports an experimental and theoretical study of the...     

Novel Whey Protein Isolate/Polyvinyl Biocomposite for Packaging: Improvement of Mechanical and Water Barrier Properties by Incorporation of Nano-silica

Journal of Polymers and the Environment - The current global proposal for withdrawing polymers with high resistance to degradation and from fossil sources from disposable appliances, as well as the...     

Distribution of potentially harmful elements in soils around a large coal-fired power plant

An understanding of the spatial distribution and contribution of a power plant to local soil contamination is important for the planning of soil use and prioritizing remedial actions for public safety. Consequently, the aim of this study was to map the spatial distribution of potentially hazardous elements (PHEs; Cu, Pb, Zn, Ni, Cr, Fe, Mn, Cd, As, and Se) in soils around a large (796 MW) coal-fired power plant in Brazil. For the purpose, 33 soil samples were collected in the area within a radius of approximately 17.5 km from the plant and subsequently analyzed for PHEs. The frequency and direction of winds were also obtained from a meteorological station in the region. The sampling area was divided into four quadrants (northwest: N-NW; northeast: N-NE; southeast: S-SE; southwest: S-SW), and there were significant negative correlations between the distance and the concentrations of Se in the S-SE quadrant and As in the S-SW and S-SE quadrants. There were positive correlations between distance from the plant and the concentration of Mn in the N-NE quadrant and the concentration of Cd in the S-SW quadrant. The dominant direction of the winds was N-NE. The indexes used in this study showed low-to-moderate enrichment factor, but detailed analysis of the dominant quadrant of the winds showed a correlation with higher concentrations in the soils closer to the power plant for at least seven of the PHEs analyzed, especially with regard to As. Therefore, we conclude that the distribution of the metalloid As can be used as a marker of the spatial distribution of contamination from the thermoelectric plant, but the dynamics of the other elements suggests that the presence of other sources of contamination may also compromise the quality of local soils.