Toxicological responses in Laeonereis acuta (annelida, polychaeta) after arsenic exposure

Several environmental pollutants, including metals, can induce oxidative stress. So, the objective of this study was to evaluate the effects of arsenic (As(III), as As(2)O(3)) on the antioxidant responses in the polychaete Laeonereis acuta. Worms were exposed to two environmentally relevant concentrations of As, including the highest previously allowed by Brazilian legislation (50 microg As/l). A control group was kept in saline water (10 per thousand) without added metal. It was observed that: (1) a peak concentration of lipid peroxide was registered after 2 days of exposure to 50 microg As/l (61+/-3.2 nmol CHP/g wet weight) compared to the control group (43+/-4.5 nmol CHP/g wet weight), together with a lowering of the activity of the antioxidant enzyme catalase (-47 and -48%, at 50 or 500 microg As/l respectively) and a higher superoxide dismutase activity (+305% at 50 microg As/l with respect to the control group); (2) a lower conjugation capacity through glutathione-S-transferase activity was observed after 7 days of exposure to 50 microg As/l (-48% compared to the control group); (3) a significant increase in As concentration was verified after 1 week of exposure to both As concentrations (50 and 500 microg/l); (4) worms exposed to As showed a limited accumulation of related methylated As species and the levels of non-toxic As species like arsenobetaine (AsB) and arsenocholine (AsC) remained unchanged during the exposure period when compared with the controls. Overall, it can be concluded that As interfered in the antioxidant defense system of L. acuta, even at low concentrations (50 microg/l) that Brazilian legislation previously considered safe. The fact that worms exposed to As showed high levels of methylated As species indicates the methylation capability of L. acuta, although the high levels of inorganic As suggest that not all the administered As(III) (as As(2)O(3)) is completely removed or biotransformed after 7 days of exposure.     

Do penguins dare to walk at night? Visual cues influence king penguin colony arrivals and departures

Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time on land and did not proceed to their young (located in crèches) along straight paths. Moreover, breeding birds' arrivals and departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity levels. This study is the first step in unveiling the mysteries of king penguin orientation on land.     

Microstructures of Antarctic cidaroid spines: diversity of shapes and ectosymbiont attachments

The echinoderm endoskeleton, located in the connective layer of the tegument, is organized into a three-dimensional mesh, the stereom. Among echinoids, the cidaroids depart from this pattern, and the shaft of the spine lacks an epidermis. Thus, the spines lack antifouling protection, allowing ectosymbionts such as bryozoans and foraminiferans to attach. This raises a question about the adaptive role of the cortical layer of the stereom. This study examined the micro- and mesostructure of the spines of 11 cidaroid species collected in the Weddell Sea and Drake Passage, and the nature of their ectosymbiont attachments. Scanning electron microscopy was used to characterize the cortex surface and X-ray micro computed tomography (μCT) to describe the symbiont attachments. Spine microstructure features provide a useful taxonomic character for distinguishing among three species in the genus Ctenocidaris, and challenge a previous parasitic interpretation of cortical filaments on the spines of Rhynchocidaris triplopora. Ectosymbiont attachments were classified as Anchoring, Molding, Cementing, or Corroding. The study suggests that some microstructure features may be protective, keeping the ectosymbionts away from the cortex and loosely attached at intervals along the shaft of the spine, while other micro-structures facilitate attachment over considerable areas of the shaft. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Motility of cryopreserved spermatozoa for the ecotoxicological evaluation of aquatic environments

A new approach to environmental studies was investigated by the authors, who propose the use of cryopreserved biological systems in ecotoxicological bioassays. The feasibility of spermiotoxicity tests using cryopreserved semen of the sea bream Sparus aurata, with sperm motility parameters as the endpoint, was evaluated. Thawed sperm was incubated in environmental samples (sediment elutriate and dumpsite leachate) and in a reference toxicant (cadmium) at scaled concentrations. Motility was then evaluated by video-microscopy using both visual and computer-assisted analyses. Activation time, sperm motility and velocity and motility duration were assessed on thawing and at the end of the incubation time, and the difference with respect to the control was statistically evaluated. All the endpoints of the bioassay proved to have good sensitivity even at the highest dilutions of the tested matrices. Observed differences in the sensitivity thresholds of the endpoints were considered to be representative of different aspects of sperm physiology. Therefore the proposed bioassay is a promising starting point for the development of toxicity tests that are increasingly tailored to the needs of ecotoxicology and environmental quality evaluation strategies for aquatic environments.     

Can a marine pest reduce the nutritional value of Mediterranean fish flesh?

Biological invasions are deemed as one of the most severe threats to biodiversity and can result in huge economic impacts on natural resources. Many studies have assessed structural changes caused by the introduction of nonindigenous species, but urgent questions remain to be answered about the complex indirect effects of invasive pests on marine biodiversity at the species and ecosystem level. Previous investigations focusing on the biological invasion by Caulerpa racemosa in the Mediterranean indicated that the lipophilic algal metabolite caulerpin accumulates in the tissues of the native edible white sea bream Diplodus sargus feeding on the exotic alga. The level of caulerpin in D. sargus has been thus used as an indicator of the trophic exposure of the fish to the seaweed and related with adverse effects on the fish health. In the present study, we show that the C. racemosa-based diet can also alter muscle fatty acids composition in the white sea bream by reducing the percentage of polyunsaturated fatty acids of the n-3 and n-6 series, such as eicosapentaenoic (C20:5), docosahexaenoic (C22:6) and arachidonic acids (C20:4). This represents both a real threat to the health of fish unable to biosynthesize these essential fatty acids and an impoverishment of an important source of essential fatty acids for human nutrition, which helps to prevent cardiovascular diseases, diabetes, hepatic steatosis, cancer and neurological disorders. On the whole, this work sheds light on an unexplored and critical aspect of biological invasions with implication on the health of both humans and the environment.     

Bisphenol A and Bisphenol S release in milk under household conditions from baby bottles marketed in Italy

A simple and sensitive validated analytical method based on liquid chromatography coupled to tandem fluorescence (FD) and ultraviolet (UV) spectrophotometry was applied to monitor the presence of bisphenol A and bisphenol S in plastic baby bottles marketed in Italy. The limits of detection (LOD) were 3.75 ng mL^?1 and 80.00 ng mL^?1, and those of quantification (LOQ) were 12.51 ng mL^?1 and 260.00 ng mL^?1 for BPA (FD detection) and for BPS (UV detection), respectively. BPA was found in only four samples, two samples undergone to microwave heating and two samples undergone to bottle warmer heating either at 40°C or at 80°C. Although the quantities of leached BPA were well below the reference dose for daily intake established by the European Food Safety Authority (EFSA) (4.0 µg kg^?1 bw/day), the release of BPA and BPS from these plastic materials should be carefully considered by the government authorities to increase people's awareness on this issue and to protect the most vulnerable population group.     

Crossing technology and sustainability in cities’ development

This paper deals with sustainability in cities and the role technology plays in furthering sustainable results. Recently, many interventions have been implemented in cities to propose paths and models promoting the sustainability of cities from an overall perspective. Technologies are favouring the achievement of aims recalling the three spheres of sustainability as proposed by Arcadis (2017), namely “planet”, “profit”, and “people”. The ties between technology and the three spheres are investigated through a content analysis of reports issued by the 10 cities with the most significant advances in terms of becoming sustainable cities, as indicated in the Arcadis Report 2016. The results highlight technology as an element crossing sustainability, as processes and models in cities management and service provisions to citizens are significantly changing. New tools are innovating the processes addressing environmental issues, thus leading to cost efficiency and better economic conditions. Parallel to this, new models for city management and the provision of public services are addressing the need for a better quality of life for citizens and cities’ other stakeholders. Technology itself is thought of as sustainable because it should lead to efficiency and being efficient itself. A qualitative cluster analysis and a focus on excerpts from reports are proposed to highlight the ties between technologies and the elements representing key issues in managing and leading a city towards more sustainable conditions.     

Public regulatory relief and the adoption of environmental management systems: a European survey

An increasing number of organizations across the world have adopted Environmental Management Systems (EMSs) based on certifiable standards, notably the European Eco-Management and Audit Scheme (EMAS) and the ISO 14001 standards. Although the specialized literature has studied the motivations, obstacles and benefits of the adoption of these standards for EMSs extensively, the impact of the public incentives on the adoption of such environmental management tools has been overlooked. In order to fill this gap in the literature, this article aims to shed light on the level of companies' knowledge and application of the main regulatory relief initiatives provided by public administrations around the EU for organizations with a certified EMS. For that purpose, this article summarizes the main findings of a survey carried out with the participation of 244 European EMAS-registered organizations. The findings of the survey highlight the fact that most of the surveyed companies have adopted or benefitted from some form of regulatory relief, mainly by making use of the measures granting an extended duration of some permits (44%), reductions in financial guarantees in the waste-treatment sector (31%) and tax reductions (26%). Moreover, it emerges that, among countries, the role of regulatory relief to support companies in the path to the adoption of EMSs is not univocal.     

Bioherbicidal activity of a germacranolide sesquiterpene dilactone from Ambrosia artemisiifolia L.

Ambrosia artemisiifolia L. (common ragweed) is an invasive plant whose allelopathic properties have been suggested by its field behaviour and demonstrated through phytotoxicity bioassays. However, the nature of the molecules responsible for the allelopathic activity of common ragweed has not been explored. The main objective of this study was to identify the phytotoxic molecules produced by A. artemisiifolia. A preliminary investigation has indicated that a methanol extract of A. artemisiifolia completely inhibited the germination of cress and radish. Semi-preparative fractionation of the methanol extract allowed separating of phytotoxic fraction which contained a single compound. The structure of this compound was elucidated by liquid chromatography–mass spectrometry (LC-MS)/MS, high-resolution mass spectral, nuclear magnetic resonance, and Fourier transform infrared spectra as sesquiterpene lactone isabelin (C₁₅H₁₆O₄). The effect of pure isabelin was tested on four different weed species, confirming the inhibitory activity of molecule. The results indicate directions for the future studies about herbicidal specific activity of isabelin, as pure molecule or in the crude extract, as a potential candidate for biological weed control.