The interaction between reproductive cost and individual quality is mediated by oceanic conditions in a long-lived bird

Environmental variability, costs of reproduction, and heterogeneity in individual quality are three important sources of the temporal and interindividual variations in vital rates of wild populations. Based on an 18-year monitoring of an endangered, recently described, long-lived seabird, Monteiro's Storm-Petrel (Oceanodroma monteiroi), we designed multistate survival models to separate the effects of the reproductive cost (breeders vs. nonbreeders) and individual quality (successful vs. unsuccessful breeders) in relation to temporally variable demographic and oceanographic properties. The analysis revealed a gradient of individual quality from nonbreeders, to unsuccessful breeders, to successful breeders. The survival rates of unsuccessful breeders (0.90 +/- 0.023, mean +/- SE) tended to decrease in years of high average breeding success and were more sensitive to oceanographic variation than those of both (high-quality) successful breeders (0.97 +/- 0.015) and (low-quality) nonbreeders (0.83 +/- 0.028). Overall, our results indicate that reproductive costs act on individuals of intermediate quality and are mediated by environmental harshness.     

Individual differences in sampling behaviour predict social information use in zebra finches

When animals have to decide where to forage, what to eat or with whom to mate, they can base their decisions on either socially or personally acquired information. In accordance with theoretical predictions, there is experimental evidence that animals adjust the weight they give to both sources of information depending on circumstances. Notably, several studies have demonstrated that individuals rely more on social information when personal information is difficult to acquire or unreliable, because these conditions leave them uncertain as how to behave. Yet, even when individuals are exposed to the same conditions, they generally differ widely in the value they attribute to social and personal information. These differences suggest that the tendency to rely on social information would also depend on intrinsic characteristics that affect, for instance, individual efficiency in collecting personal information. To address this issue, we conducted laboratory experiments using female zebra finches (Taeniopygia guttata) and we tested them under three consecutive conditions. First, we evaluated their reliance on social information in a mating context and in a foraging context. Then, we measured their efficiency in acquiring personal information by recording their sampling behaviour when searching for hidden food. We found that females that sampled their environment less actively consistently relied on social information to a greater extent compared with those that invested more in sampling. Contrary to what is generally assumed, then, our study demonstrates that social information use is not entirely flexible and context dependent.     

Importance of colloids in the transport within the dissolved phase (<450 nm) of artificial radionuclides from the Rhône river towards the Gulf of Lions (Mediterranean Sea)

The significance of colloidal fractions regarding the transport of artificial radionuclides in natural water systems is underlined by using sequential ultrafiltration both in the Rh?ne freshwater and the marine area under and outside the influence of the river outflow. Indeed, the Rhodanian aquatic system represents an interesting test site as various artificial radionuclides are released into the Rh?ne river by several nuclear installations. We focused our study on (137)Cs, (106)Ru, (60)Co, (238)Pu and (239+240)Pu. Our results show that Fe, Al and Organic carbon (OC) are the main components of colloidal matter. Colloids represent about 15% of dissolved (<450 nm) OC and 25% of dissolved Fe and Al exported towards the sea. Within the dissolved (< 450 nm) phase, these colloidal compounds are shown to account for the transport of 40% for both Co and Ru, 60% for (238)Pu and (239+240)Pu and have no significance on (137)Cs flux.     

Radon-222 signatures of natural ventilation regimes in an underground quarry

Radon-222 activity concentration has been monitored since 1999 in an underground limestone quarry located in Vincennes, near Paris, France. It is homogeneous in summer, with an average value of 1700 Bq m(-3), and varies from 730 to 1450 Bq m(-3) in winter, indicating natural ventilation with a rate ranging from 0.5 to 2.4 x 10(-6) s(-1) (0.04-0.22 day(-1)). This hypothesis is supported by measurements in the vertical access pit where, in winter, a turbulent air current produces a stable radon profile, smoothly decreasing from 700 Bq m(-3) at 20 m depth to 300 Bq m(-3) at surface. In summer, a thermal stratification is maintained in the pit, but the radon-222 concentration jumps repeatedly between 100 and 2000 Bq m(-3). These jumps are due to atmospheric pressure pumping, which induces ventilation in the quarry at a rate of about 0.1 x 10(-6) s(-1) (0.009 day(-1)). Radon-222 monitoring thus provides a dynamical characterisation of ventilation regimes, which is important for the assessment of the long-term evolution of underground systems.     

Conflicts between stakeholder groups affecting the ecology and economy of the Segara Anakan region

This study analyses how the conflict potential between different stakeholder groups is affecting the ecology and economy of the Segara Anakan region, a mangrove-fringed lagoon in central Java, Indonesia. The lagoon’s increasing sedimentation/silting up and the area’s expanding population has led to various interest groups conflicting with one another over how the resources of the lagoon and its surrounding area are to be utilized. Conflicts arise between occupational and ethnic groups in the lagoon’s bordering villages in the context of a transformation from fisheries to wetland agriculture. Land and mangrove use is therefore a cause for conflict between multiple groups, including Javanese fishermen, Sundanese farmers from Central and West Java and external shrimp farm owners. A result of the “Segara Anakan Development Project”—an 8-year undertaking that began in 1996—is that the lagoon was frequently dredged. Due to the dredging and resulting contamination of the land, a regional clash was triggered between Sundanese farmers and Javanese fishers. Our study reveals that the conflict potential between the various interest groups in the Segara Anakan Lagoon area could be reduced if the scarcity of natural resources were alleviated. Religious aspects also play a large role in marine resource utilization. Recognizing that the human utilization of natural resources is strongly symbolic and thereby culturally defined, we unravel the resource conflicts in our study area and offer some strategic approaches towards more sustainable outcomes.     

Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders

Coal tars have been identified as posing a threat to human health due to their toxic, mutagenic and carcinogenic characteristics. Workers involved in former gasholders decommissioning are potentially exposed to relevant concentrations of volatile and semi-volatile hydrocarbons upon opening up derelict tanks and during tar excavation/removal. While information on contaminated sites air-quality and its implications on medium-long term exposure is available, acute exposure issues associated with the execution of critical tasks are less understood. Calculations indicated that the concentration of a given contaminant in the gasholder vapour phase only depends on the coal tar composition, being only barely affected by the presence of water in the gasholder and the tar volume/void space ratio. Fugacity modelling suggested that risk-critical compounds such as benzene, naphthalene and other monocyclic and polycyclic aromatic hydrocarbons may gather in the gasholder air phase at significant concentrations. Gasholder emissions were measured on-site and compared with the workplace exposure limits (WELs) currently in use in UK. While levels for most of the toxic compounds were far lower than WELs, benzene air-concentrations where found to be above the accepted threshold. In addition due to the long exposure periods involved in gasholder decommissioning and the significant contribution given by naphthalene to the total coal tar vapour concentration, the adoption of a WEL for naphthalene may need to be considered to support operators in preventing human health risk at the workplace. The Level I fugacity approach used in this study demonstrated its suitability for applications to sealed environments such as gasholders and its further refining could provide a useful tool for land remediation risk assessors.     

Chemical Changes in Sediment Pore-Waters of an Acidic Mining Lake After Addition of Organic Substrate and Lime for Stimulating Lake Remediation

In the past five years, enclosures have beeninstalled in an acidic mining lake in Lusatia to investigate insitu remediation processes. They were treated with straw, withstraw and Carbokalk, or with Carbokalk alone, where Carbokalkis a by-product of the sugar industry (solid precipitate ofnon-sugars after lime clarification of extracted sugar beetjuice). Sediment samples were taken as cores to get informationabout the behaviour of organic and inorganic components insediment pore-water with depth. Vertical distributions of pH,soluble reactive phosphate, nitrate, ammonium, silica,aluminium, iron, manganese, calcium, magnesium, sodium,potassium, sulphate, and DOC were measured. The resultingprofiles, each consisting of 15 data points at differentdepths, were compared by cluster analysis. The similarities ofsediment cores from different treated enclosures relating toprofiles of chemical components were discussed. Increasedconcentrations of potassium and sulphate were found in pore-water after substrate treatment. The data imply dissolution ofpotassium iron sulphate hydroxide minerals (jarosite) after anincrease of pH caused by dissolution of lime and by sulphatereducing processes which were stimulated by organic substrateaddition.     

Landscapes and environments on the island of Ouessant,Brittany, France: From traditional maintenance to the management of abandoned areas

For about 50 years the desertion of areas by traditional activities has led to an important evolution of landscapes and environments on the island of Ouessant. The study of this evolution has been undertaken at different spatial and temporal scales. On one part of the island, a scientific investigation carried out at the scale of the parcel enabled the form of the landscape in 1850 to be compared with that of 1985. On the whole island, the evolution of spatial organization and land use was compared between 1950 and 1985. For each of three main ecological environments, vegetational successions after the decrease of agriculture have been studied along with their future potential changes. This work highlights some considerations about the present management of the environment in relation to the major objectives of island environmental policies.     

Soil-plant nitrogen isotope composition and nitrogen cycling after biochar applications

Environmental Science and Pollution Research - Biochar has strong potential to improve nitrogen (N) use efficiency in both agricultural and horticultural systems. Biochar is usually co-applied with...