Assessing a Quick Monitoring Method Using Rocky Intertidal Communities as a Bioindicator: A Multivariate Approach in Algeciras Bay

A multivariate approach was used to test the value of intertidal communities as a bioindicator of environmental conditions at Algeciras Bay, southern Spain. The study area is located in the Strait of Gibraltar and it is subjected to a variety of anthropic impacts. Eight localities (5 inside and 3 outside the bay) were selected, and four transects were undertaken in each locality to characterise the fauna and flora. The spatial distribution of the intertidal species reflected the physico-chemical conditions of Algeciras Bay. The stations located outside the bay, characterised by high hydrodynamism and dissolved oxygen and low sedimentation and turbidity, had a higher diversity and species richness than the inner stations. According to the BIO-ENV procedure and CCA, water turbidity was the factor which best correlated with the intertidal assemblages. SIMPER showed that the molluscs Chtamalus stellatus, Mytilus cf edulis, Littorina neritoides and Balanus perforatus, and the algae Gelidium pusillum, Corallina elongata, Asparagopsis armata, Colpomenia sinuosa and Fucus spiralis were the species that most contributed to the dissimilarity between internal and external sites. The present study, based on the spatial distribution of intertidal taxa, yielded similar results to those previously obtained in the area with costly physico-chemical analysis based on complex matrices of subtidal epifaunal communities. Consequently, the intertidal sampling method proposed in this study is presented here as a quick, effective alternative strategy, and can be useful in environmental monitoring programs, since these communities are easily accessible and amenable to sample, and the sessile nature of the majority of the species makes future, long-term monitoring relatively simple.     

Assessment Of Trampling Simulation Impacts On Native Vegetation In Mediterranean Sclerophyllous Forest

This study examines the effects of visitors on vegetation of natural semi-arid areas of Mediterranean basin using controlled experimental trampling. Impacts were assessed on days 1, 5, 15 and 30 examining presence of plant species, their cover and height in linear transects suffering a constant trampling intensity (25, 75, 100 and 200 passes/day). In addition, the study included the analysis of factors such as plant species, trampling intensity, the cumulative impact (day effect) and the type of footwear on plant variables. The results showed a decrease on plant cover and height influenced by cumulative (day) effect, an effect of trampling intensity and a different effect for each species. In contrast, shoe type affected only slightly the decrease in plant height. The evolution of plant cover revealed which species were most resistant to trampling. The disappearance of plant individuals during trampling appeared to be an impact index better than plant cover, because cover increased in some species when they were trampled thus introducing a bias.     

Modified CDKN2B (p15) and CDKN2A (p16) DNA methylation profiles in urban pesticide applicators

Environmental Science and Pollution Research - Gene-specific changes in DNA methylation by pesticides in occupationally exposed populations have not been studied extensively. Of particular concern...     

Root uptake of atenolol,sulfamethoxazole and carbamazepine,and their transformation in three soils and four plants

Soils can be contaminated by pharmaceuticals. The aim of this study was to evaluate the impact of soil conditions (influencing sorption and persistence of pharmaceuticals in soils) and plant type on the root uptake of selected pharmaceuticals and their transformation in plant-soil systems. Four plants (lamb’s lettuce, spinach, arugula, radish) planted in 3 soils were irrigated for 20 days (26) with water contaminated by one of 3 pharmaceuticals (carbamazepine, atenolol, sulfamethoxazole) or their mixture. The concentrations of pharmaceuticals and their metabolites in soils and plant tissues were evaluated after the harvest. Sulfamethoxazole and atenolol dissipated rapidly from soils. The larger concentrations of both compounds and an atenolol metabolite were found in roots than in leaves. Sulfamethoxazole metabolites were below the limits of quantifications. Carbamazepine was stable in soils, easily uptaken, accumulated, and metabolized in plant leaves. The efficiency of radish and arugula (both family Brassicaceae) in metabolizing was very low contrary to the high and moderate efficiencies of lamb’s lettuce and spinach, respectively. Compounds’ transformations mostly masked the soil impact on their accumulation in plant tissues. The negative relationships were found between the carbamazepine sorption coefficients and its concentrations in roots of radish, lamb’s lettuce, and spinach.

     

Methods for the Sustainable Rebuilding of Overexploited Natural Resources

In this paper, we introduce an approach based on viability theory for designing rebuilding programs for overexploited natural resources. Instead of using the so-called viability kernel, as is usual in the applications of viability theory, we consider the set of sustainable thresholds, which represents the constraints (parametrized by thresholds) that can be sustained from the current level of the resources under study over time. The recovery of the Southern hake in Chile is presented as an example to illustrate the proposed approach.     

Ivermectin dissipation and movement from feces to soil under field conditions

The aim of this work was to evaluate the fate of ivermectin (IVM) at two concentrations in cattle feces and its movement to the nearby soil and plants. Feces were spiked with IVM at two levels: 3000 ng g^?1 (high group, HG) and 300 ng g^?1 (low group, LG). Artificial dung pats were prepared and deposited in an experimental field area. Feces and underlying soil were sampled up to 60 days post-deposition (dpd). As an additional analysis, grasses growing around the pats were sampled at 30 and 60 dpd. Ivermectin concentrations in all matrices were determined by HPLC. Mean IVM fecal concentrations were in the range between 3901.9 ng g^?1 and 2419.2 ng g^?1 (high group) and 375.3 ng g^?1 and 177.49 ng g^?1 (low group). Mean times for 50% and 90% dissipation were 88.23 and 293.03 days (HG) and 39.1 and 129.9 days (LG). Soil concentrations ranged from 26.1 ng g^?1 to 71.1 ng g^?1 (HG) and 3.4 to 5.9 ng g^?1 (LG); in plants, concentrations were between 71.4 and 380.8 ng g^?1 and 5.40 and 51.8 ng g^?1 in HG and LG, respectively. These results confirm that IVM moves from feces to the underlying soil as well as to nearby plants. The potential risk of detrimental effects on soil organisms and the impact on herbivorous animals should be further evaluated.     

Land cover effects on water balance partitioning in the Colombian Andes: improved water availability in early stages of natural vegetation recovery

Regional Environmental Change - Vegetation actively affects different components of the water budget in multiple spatial and temporal scales. Changes in vegetation cover and structure—such as...     

Trends in social metabolism and environmental conflicts in four Andean countries from 1970 to 2013

In the global map of environmental injustices (http://www.ejatlas.com), the Andean countries (AC) report many ecological distribution conflicts. Our hypothesis is that the patterns of such conflicts are explained by the structural shifts of the economies and the concomitant changes in their metabolic profiles. Since the 1990s, these countries went through a strong reprimarization process, which changed their social metabolism as well as intensified environmental pressures and conflicts. In monetary terms, in the AC group of countries (Colombia, Ecuador, Peru and Bolivia), the primary sector increased its importance both in exports as well as in GDP. In the metabolic dynamics, the Domestic Extraction of materials (measured in tons) increased by a factor of 3.4 after jumping from 336 to 1145 MT between 1970 and 2012. This was driven by the fossil fuel and mining sectors. This reality was reflected in the environmental conflicts. Mining, fossil fuels, biomass and hydropower plants are the most conflictive sectors. The research in this article relies on a study of material flow analysis for the four AC carried out by the authors as well as 244 environmental conflicts reported in the EJAtlas until August 2016. The shifts in the metabolic–economic patterns help explain the dynamics and characteristics of the environmental conflicts in the AC. Such conflicts produce social mobilizations, which if successful, might help move society towards sustainability and environmental equity.     

Determination of pesticides of different chemical classes in drinking water of the state of Santa Catarina (Brazil) using solid-phase microextraction coupled to chromatographic determinations

The evaluation of the concentration of pesticides in drinking water presents a real concern. In this study, a simple and rapid method based on solid-phase microextraction (SPME) followed by gas chromatography–mass spectrometry and electron capture detectors was developed aiming at multiclass determination of 23 pesticides regulated by the Brazilian legislation. The extraction was carried out by direct immersion mode (DI-SPME) using DVB/Car/PDMS fiber coating. In order to improve the extraction efficiency, parameters such as temperature, salting-out effect, and extraction time were optimized. The method was evaluated using drinking water samples spiked with the analytes at different concentrations, and it showed good linearity in the range studied. The values obtained for limits of quantification (LOQ) were below the limits established by Brazilian regulations. Accuracy and precision of the method exhibited satisfactory results, providing relative recoveries from 70 to 123.34% at three spiked levels, and the relative standard deviations ranged from 0.53 to 24.8%. The method was applied in 20 drinking water samples from 13 cities in the State of Santa Catarina, Brazil.

     

Effects of insecticides used in strawberries on stingless bees Melipona quadrifasciata and Tetragonisca fiebrigi (Hymenoptera: Apidae)

Environmental Science and Pollution Research - The use of pesticides is considered one of the most important threats to pollinators, especially since they are widely used in agriculture for pest...