Using lysosomal membrane stability of haemocytes in Ruditapes philippinarum as a biomarker of cellular stress to assess contamination by caffeine, ibuprofen, carbamazepine and novobiocin

Although pharmaceuticals have been detected in the environment only in the range from ng/L to g/L, it has been demonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability (LMS) has previously been applied as an indicator of cellular well-being to determine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay (NRRA). Clams were exposed in laboratory conditions to caffeine (0.1, 5, 15, 50 μg/L), ibuprofen (0.1, 5, 10, 50 μg/L), carbamazepine and novobiocin (both at 0.1, 1, 10, 50 μg/L) for 35 days. Results show a dose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassay was significantly reduced by 50% after exposure to environmental concentrations (p < 0.05) (caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L), compared to controls. Clams exposed to these pharmaceuticals were considered to present a diminished health status (retention time < 45 min), significantly worse than controls (96 min) (p < 0.05). The predicted no environmental effect concentration (PNEC) results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.     

Characterization of acute toxicity,genotoxicity, and oxidative stress of dimethoate in Rhinella arenarum larvae

Environmental Science and Pollution Research - There is a great concern worldwide about the global decline of amphibians, particularly by agrochemical pollution. The aim of this study was to assess...     

Isolation and identification of intermediates from biodegradation of low chlorinated biphenyls (Delor-103)

Microorganism Pseudomonas species P2 metabolizes polychlorinated biphenyls (PCBs) and biphenyl, producing the whole spectrum of intermediates, among them coloured intermediates, which are suitable for the monitoring of PCBs degradation by optical sensors. Knowledge of chemical structures and conditions of development of colour metabolites is necessary for application of optical analytical methods. The main goal of this work was the isolation and identification of intermediates from the biodegradation of the mixture of low chlorinated biphenyls (Delor-103), which is based on the solid phase extraction (SPE) of the whole mixture using LiChrolut EN cartridges, then silylation of the extract as one way to the identification of one part of intermediates by GC-MS, and acetylation of the extract as a way for the further concentration and analysis of more polar chlorobiphenylols and chlorobiphenyldiols. The combination of SPE and following acetylation allows to obtain chlorobiphenylols and chlorobiphenyldiols as an almost pure fraction. The acetylation method could be also used instead SPE procedure with the same final concentration effect. Using the simulation mass spectrometry program, two new compounds, dihydrodihydroxytrichloro- and tetrahydrodihydroxytrichlorobiphenyl, as silylderivatives, were identified.     

Large-scale spatial variation in mercury concentrations in cattle in NW Spain

Mercury (Hg) is a highly toxic environmental contaminant and man-made emissions account for between a quarter and a third of total atmospheric levels. Point discharges, particularly coal-burning power stations, are major sources of atmospheric Hg and can result in marked spatial variation in mercury deposition and subsequent uptake by biota. The aims of this study were to quantify the extent to which major point and diffuse sources of atmospheric Hg emissions affected accumulation of Hg by biota throughout Galicia and Asturias, two of the major regions in northwest Spain. We did this by relating renal Hg concentrations in locally reared cattle (n=284) to the proximity of animals to point and diffuse sources of Hg emissions. Mercury residues in calf kidneys ranged between non-detected and 89.4 g/kg wet weight. Point discharges from coal-fired power plants in Galicia had the most dominant impact on Hg accumulation by calves in Galicia, affecting animals throughout the region and explaining some two-thirds of the variation in renal residues between animals located directly downwind from the plants. The effects of more diffuse emission sources on Hg accumulation in calves were not distinguishable in Galicia but were detected in cattle from neighbouring Asturias. The impact of both point and diffuse sources in elevating environmental levels of bioavailable Hg and subsequent accumulation by cattle extended to approximately 140-200 km downwind from source.     

Desperado siblings: uncontrollably aggressive junior chicks

According to the desperado sibling hypothesis, chicks of obligately siblicidal species kill their junior broodmates as early as possible because junior broodmates face dire ecological prospects and are consequently predisposed to aggressively overthrow elder broodmates by all-out aggression. The agonistic behavior of junior chicks is virtually unknown because they die so young. We investigated the agonistic behavior of hypothetical desperados by fostering junior brown boobies (Sula leucogaster, an obligately siblicidal species) into nests of the blue-footed booby (S. nebouxii, a facultatively siblicidal species) containing an older singleton blue-foot chick. Controls were junior blue-footed boobies fostered into the same situation. Junior brown boobies were 7 times more aggressive than controls and most of them dominated their elder and larger nestmates. Four of nine brown booby juniors showed relentless aggression, delivering up to 711 pecks, bites and pushes (including "expulsion pushes") per hour, thereby overwhelming nestmates 90% heavier and permanently expelling one of them from the nest. Similarly, in natural broods of two surviving brown booby chicks, the losing chick was 13 times as aggressive as blue-foot subordinates, up to at least age 7 weeks. Contrast of the two species of booby suggests the evolution of agonistic roles within broods may be partly driven by selection on potential victims to express a level and type of aggressiveness appropriate to their status-related ecological prospects.     

Negative interactions between two SW Atlantic intertidal crabs in soft-bottom habitats

The intertidal crabs Chasmagnathus granulatus and Cyrtograpsus angulatus coexist across the SW Atlantic intertidal. Previous studies in this region suggest that C. granulatus displace C. angulatus in soft sediment, where C. granulatus build burrows (“burrowing beds”). We examined variation in abundance, size-frequency distribution, sex ratio, incidence of autotomies, and diet of both species in C. granulatus crab beds and adjacent areas without burrows. We also experimentally tested the hypothesis that in the absence of C. granulatus, C. angulatus will build burrows. Only large sized individuals of C. angulatus venture into C. granulatus crab beds. The sex ratio of C. angulatus was always biased towards females, with higher bias outside crab beds (1:8 outside, 1:2 inside). Although the items consumed in the crab beds did not differ from those consumed outside, the males of C. angulatus had a higher frequency of empty stomachs in crab beds. The incidence of limb autotomies of C. angulatus was higher outside C. granulatus crab bed areas. After a long rainy period in which C. granulatus was absent from these areas, the pattern of habitat use of C. angulatus changed. During this period C. angulatus showed higher abundance in the areas, where C. granulatus previously constructed burrows, and there were no differences between areas in any of the measured parameters. In the absence of C. granulatus, C. angulatus built their own burrows and never used C. granulatus burrows. The interaction between C. granulatus and C. angulatus may be a good example of competitive exclusion, when the shared resource is the access to surface soft-sediment.     

Biotoxizitätstests mit PAK

There is great need for toxicity tests with higher plants for the investigation and monitoring of chemicals in the environment — especially for tests which are quick, easy, and inexpensive. Such tests should add to and improve current guidelines, e.g., OECD- and BBA-Guidelines. This article describes the nodulation of leguminous plants withRhizobium bacteria used in a bioassay with polycyclic aromatic hydrocarbons (PAH). Plants growing on a solid medium were exposed simultaneously to bacteria and PAH. This axenic culture system allows to observe the impact of PAH on plant growth and the interaction between plant and bacteria (nodulation). Dose-response-experiments indicated that nodulation measured as number of nodules per plant, was more sensitive to the inhibition by PAH than other plant growth parameters.     

Forest cover dynamics in the Selva Maya of Central and Southern Quintana Roo,Mexico: deforestation or degradation?

ABSTRACT

Forest cover dynamics (1993-2018) was assessed in two regions on the Yucatan Peninsula: Zona Maya (ZM), 67% indigenous with shifting cultivation and community forestry; and Bacalar–Rio Hondo (BRH), mainly commercial agriculture and pastureland. Degradation (12,915 ha y^?1) exceeded deforestation (5882 ha y^?1) and was worse in BRH. In BRH there was a net forest loss (?1.6% y^?1) associated with pastureland and commercial agriculture. In ZM, mature forest recovery (1.4% y^?1) and dynamic forest cover (continuous loss and gain) were associated with shifting cultivation. Changes were more intense during 2011–2018 and gains of mature forest in ZM and deforested areas in BRH targeted secondary vegetation. Fragments of mature and secondary vegetation decreased, and connectivity improved in ZM, but opposite trends occurred in BRH. Reporting and monitoring deforestation using Global Forest Watch data is inadequate since 62% of forest cover loss represent degrading or recovering forest cover.     

Regaining the traditional use of wildlife in wetlands on the coastal plain of Veracruz,Mexico: ensuring food security in the face of global climate change

Regional Environmental Change - Wetlands play important roles that benefit social-ecological systems. They are threatened by climate change and human activities, i.e., raising livestock and...     

The appreciation of mineral element accumulation level in some herbaceous plants species by ICP–AES method

Introduction  

From the metallurgic industry zone of Dambovita County, we harvested and analyzed seven herbaceous plants species (Lolium perenne, Festuca pratensis, Stipa capillata, Agrostis alba, Cynodon dactylon, Luzula campestris, and Agrostis tenuis) to establish the heavy metal accumulation levels in these species.