A conceptual framework for understanding illegal killing of large carnivores

The growing complexity and global nature of wildlife poaching threaten the survival of many species worldwide and are outpacing conservation efforts. Here, we reviewed proximal and distal factors, both social and ecological, driving illegal killing or poaching of large carnivores at sites where it can potentially occur. Through this review, we developed a conceptual social–ecological system framework that ties together many of the factors influencing large carnivore poaching. Unlike most conservation action models, an important attribute of our framework is the integration of multiple factors related to both human motivations and animal vulnerability into feedbacks. We apply our framework to two case studies, tigers in Laos and wolverines in northern Sweden, to demonstrate its utility in disentangling some of the complex features of carnivore poaching that may have hindered effective responses to the current poaching crisis. Our framework offers a common platform to help guide future research on wildlife poaching feedbacks, which has hitherto been lacking, in order to effectively inform policy making and enforcement.     

Influence of americium-241 on the microbial population and biodegradation of organic waste

The present study investigated the influence of ²⁴¹Am on microbial growth and the degradation of organic waste. Leachate samples collected in a lysimeter were periodically analyzed for bacterial growth, under both aerobic and anaerobic conditions. ²⁴¹Am inhibited bacterial growth, and the degradation of organic matter was delayed in comparison with the control. Minimal inhibitory concentration assays and survival curves revealed that it inhibits the growth of Pseudomonas putida F1. The assay also revealed that ²⁴¹Am is more toxic than ²³⁸U, Zn²⁺ and Cd²⁺. This study further led to the finding of four new radionuclide-tolerant bacterial strains: Flavobacterium spp., Pseudomonas gladioli, Chryseobacterium indologenes and Ochrobactrum anthropi. The survival curves of P. gladioli, C. indologenes revealed that these bacteria are resistant to metal as consortia.     

Loft features reveal the functioning of the young pigeon’s navigational system

It is thought that young homing pigeons are able to use information acquired en route for their initial homeward orientation. However, the cues involved and mechanisms utilised are under discussion. Blocking light-dependent route-specific information during the first leg of an outward journey detour, together with analysis of pigeons that were raised under different loft conditions, allowed us to correctly evaluate the functioning of this mechanism and, more generally, the navigational map of birds. Pigeons from the same stock were raised and kept in two different lofts. The birds in the experimental groups were transported to the release sites via detours, and light-dependent information was denied during the first half of the outward journey (no compass information was available). Control birds were transported by the most direct route and had access to all available information. In general, the results showed that the low-loft birds preferred to use magnetic compass cues, whereas the high-loft birds preferred to use navigational map cues to collect information of the first part of the outward journey. The impairments observed in the homing performances of the experimental groups highlight the reliability of information collected inside the map area. Relevant to an understanding of the route-reversal mechanism was the evidence that this mechanism is able to function in the absence of compass information (birds raised in a wind-exposed loft show a detour effect). In systems where directional information could be provided by multiple sources, processing and extracting accurate course trajectories through a common mechanism may prove more efficient and reliable.     

Sex,age, spleen size,and kidney fat of red deer relative to infection intensities of the lungworm <Emphasis Type="Italic">Elaphostrongylus cervi</Emphasis>

We analyzed the relationships among spleen size, body condition (measured as kidney fat), and larval counts of the nematode Elaphostrongylus cervi in red deer (Cervus elaphus). The aim was to investigate the interaction between host body condition and intensity of infection with parasites. As red deer are highly polygynous, we also tested whether these relationships varied with sex and age of the hosts. Kidney fat and spleen size were positively correlated in subadults (2–3 years old) and adults (>3 years old), but not in calves (<1 year old) or yearlings (1–2 years old). Spleen size was negatively associated with nematode load in subadult females and in adult males. These two age classes are potentially the most nutritionally stressed, as subadult hinds are still growing and often engaging in rearing their first calf, and adult stags were sampled just after the rut, which is recognized as a substantial energy drain in this age–sex class, as they compete to hold females during the mating season. Body condition related negatively to parasite count only in adult males. In the context of red deer life history, these findings suggest that spleen size is dependent on body condition and that it could be affected by variation in resource partitioning among immune defense, growth, and reproductive effort in red deer. For the first time in a wild mammal, the spleen mass is shown to be positively related to body condition and negatively related to parasite infection. We conclude that elucidating whether spleen mass reflects immune defense investment or a measure of general body condition should contribute to understanding topical issues in mammal ecology.     

New epizooic symbioses between sponges of the genera Plakortis and Xestospongia in cryptic habitats of the Caribbean

Three new cases of sponge symbiosis between species of Plakortis and Xestospongia were found in reef caves and mesophotic reef habitats of the Caribbean. Plakortis sp. 1 from the Bahamas associates exclusively with Xestospongia deweerdtae which was originally described living freely on the deep fore-reef and caves of Jamaica. In addition, we found Plakortis sp. 2 from Puerto Rico which associates with both X. deweerdtae and a different Xestospongia sp. Sponge specimens were identified using cytochrome oxidase subunit 1, 28S rRNA and 18S rRNA gene sequence fragments, spicule analysis, and histological sections with SEM. Unlike previous sponge pairs, Xestospongia spp. not only grew as a thin veneer of tissue over the Plakortis host sponge but through the mesohyl, forming inner channels (0.1–1 cm) that may provide a benefit by facilitating more efficient water transport through the dense Plakortis tissue. Symbioses with both Plakortis spp. were documented from an early recruit stage through adulthood. Spicule measurements conducted on symbiotic versus free-living X. deweerdtae revealed significantly smaller spicule sizes for symbiotic individuals, suggesting a cost in terms of silicon availability, or a benefit in terms of a lower investment in skeleton synthesis for support. This study reveals new specialized symbiotic associations between distantly related sponge genera that likely represent an alternative strategy of adaptation for life in reef caves and mesophotic reefs.     

The proton binding properties of biosorbents

Environmental Chemistry Letters - A broad variety of materials of biological origin have been successfully used in recent decades for the removal of pollutants from waters. These biosorbents...     

Globalization and natural resources: the expansion of the Spanish agrifood trade and its impact on water consumption, 1965–2010

Beginning in 1960, the Spanish agricultural sector underwent an intensive process of development, resulting in important structural changes, not only in the sector itself, but also in the relationship of the agrarian system to natural resources. These changes were closely related to the growth of per capita income and Spain’s increasing integration into international markets. In the last five decades, the volume of Spanish agricultural trade has increased strongly, with a concomitant increase in the consumption of domestic water resources, requiring the construction of water infrastructure for irrigation. This paper examines the impact on water use in Spain during a period of economic modernization and trade liberalization. More specifically, we are interested in obtaining virtual water trade flow trends and identifying the major drivers responsible for these trajectories, via a decomposition analysis. Our results point to a large increase in virtual water exports and imports, primarily driven by the scale effect, that is, by the growing integration into international markets. The composition effect and changes in water intensity entailed a moderation in water consumption.     

Toxicity evaluation of cypermethrin,glyphosate, and malathion,on two indigenous zooplanktonic species

In Aguascalientes, Mexico, there is a special concern about pesticides because of their intensive use on guava production areas, which are located in the vicinity of water reservoirs; thus, non-target organisms could be exposed. Thereafter, the aim of this work was to assess the effect of cypermethrin, Faena® (glyphosate), and malathion, which are the most used pesticides in Aguascalientes’ guava production, on the indigenous freshwater species Alona guttata (cladoceran) and Lecane papuana (rotifer). Acute 48-h toxicity tests were carried out, and LC₅₀ values were calculated. Then, five sublethal concentrations (1/80, 1/40, 1/20, 1/10, and 1/5 of the respective LC₅₀) were selected for the chronic assays: (a) intrinsic growth rate analysis in the rotifer and (b) partial life table analysis in the cladoceran. The results of the acute toxicity tests showed that A. guttata was more sensitive to malathion (LC₅₀ = 5.26 × 10^?3 mg/L) at concentrations found in natural environments with continuous application on guava fields, whereas L. papuana was more sensitive to Faena® (LC₅₀ = 19.89 mg/L). The somatic growth of A. guttata was inhibited for the chronic exposure to cypermethrin. In addition, cypermethrin and Faena® seemed to exert endocrine disruptive effects on A. guttata. Moreover, malathion chronic exposure significantly decreased the survival of A. guttata. Moreover, L. papuana was affected chronically for the three pesticides.     

Influence of a flooding event discharge on accretion in wetlands

Flooding events in wetlands transport sediment particles landwards and can increase accretion in some areas of the wetland or resuspend the sediment in other areas. In this study a flooding event with different water discharges was analyzed in a laboratory simulated wetland to determine the effect stem density has on particle trapping. The discharge that entered the simulated wetland was a particle laden barotropic current that initially produced a pulse that traveled through the wetland. After the first pulse, a baroclinic current, with a different timescale to the initial pulse, developed. Three stem densities, along with the ‘without plant case’, were considered. A semi-empirical model was formulated to explain the propagation of the water pulse. The model predicted the velocity of the pulse dampening in the presence of the simulated vegetation, by using the roughness parameter that had been found to increase with stem density. The baroclinic current propagated at a lower velocity than the pulse did, and its velocity decreased with stem density. As less sediment was found in the wetland with denser canopies, this indicates that the presence of a canopy acts as a barrier to sediment transportation. Furthermore, a greater amount of sediment was deposited in regions at the foot of the denser vegetated wetland zone and the sediment deposition also increased with the water discharge.     

A new hazard index of complex mixtures integrates bioconcentration and toxicity to refine the environmental risk assessment of effluents

A new methodology to evaluate the overall environmental hazard of unknown mixtures, based on bioconcentration potential and toxicity, was developed using a combination of two methodologies: 1) the estimation of the octanol-water partition coefficient (K(ow)) using reverse-phase high performance liquid chromatography (RP-HPLC) and 2) the toxicity identification evaluation (TIE). Forty seven compounds with known K(ow) and different molecular structures where used for the calibration of the log K(ow) in relation to the retention time in reverse-phase high performance liquid chromatography (RP-HPLC). A linear regression with an R(2)=0.81 and an sd=0.69 was established between log K(ow) and RP-HPLC retention time. This K(ow) estimation method was furthermore validated using seven additional compounds, showing acceptable estimations of the log K(ow) of unknown substances. Two different mixtures were tested, one containing 3,4 Dichloroaniline, Diazinon and 4-Nonylphenol and another one containing a mixture of 16 pesticides. Both mixtures were first tested as a whole effluent and then fractionated and tested, using a miniaturized Daphnia magna test. An equation is presented, that combines both methodologies and establishes a relative hazard index RHI, ranging from 1 to 10 for any particular mixture of chemicals. The results show how the method presented can refine the security factors that could be included in the environmental risk assessment of effluents in the future.