Genetic connectivity of the ecosystem engineer Perumytilus purpuratus north to the 32°S southeast Pacific ecological discontinuity

Connectivity in benthic marine animals with complex life cycles occurs primarily during the pelagic larval stage and depends deterministically on oceanographic dynamics. The scale of such larval dispersal is highly uncertain due the difficulty of direct measurement and poor knowledge of larval dynamics and ocean flow variability. This study characterizes the pattern of genetic connectivity in the ecosystem engineer Perumytilus purpuratus between latitudes 23°S and 33°S, which includes the ecological discontinuity reported for many taxa north to 32°S at the southeast Pacific. The genetic discontinuity observed in P. purpuratus around 26°S is described herein while that detected at 28°S is in line with the ecological discontinuity (in coverage, recruitment and density) previously reported for this mussel between 28°S and 32°S. Both discontinuities delimitate two major gene pools upon Bayesian inferences on geographical variation of five microsatellite loci. Interestingly, marker Pepu1 was responsible for most variation between pools and was potentially under selection. In fact, inferences excluding Pepu1 produced a single gene pool (k = 1) in central-northern Chile. The IBD connectivity pattern observed among P. purpuratus beds distributed in the interval 23°S–33°S is congruent with processes driven by larval dynamics, and the dominant equatorward Humboldt Current along a coast largely unaffected by ice during the last Pleistocene glaciation. However, the selective scenario unveiled by microsatellite Pepu1 inside the 25°S–28°S ecological discontinuity is consistent with selective processes associated with specific mesoscale properties operating in this area. This study highlights the usefulness of integrating different oceanographic scales, ecological data and population genetics to better understand connectivity of benthic marine species.     

烟花燃放气对环境和健康影响与管理对策研究

春节期间,烟花燃放产生的烟气含有重金属的微小粒子,对城市环境空气中污染物浓度的上升关联度较高。燃放期间空气中的颗粒物成分和重金属成分浓度急剧升高,对市民的身体健康影响很大,使医院中呼吸系统、心脑血管系统等急性病症的发生率也相应升高。为了减轻烟花燃放可能对环境和人体造成的不利影响,建议节日期间不燃放或适当、适量地燃放烟花爆竹,提高烟花爆竹产品的科技含量以及全社会共同监管烟花爆竹的生产、流通、分配、消费等活动。     

Use of ecosystem information to improve soil organic carbon mapping of a Mediterranean island

Detailed maps of soil C are needed to guide sustainable soil uses and management decisions. The quality of soil C maps of Italian Mediterranean areas may be improved and the sampling density reduced using secondary data related to the nature of the ecosystem. The current study was conducted to determine: (i) the improvements obtainable in mapping soil C over a Mediterranean island by using ecosystem features and (ii) the effect of different sampling densities on the map accuracy. This work relied on field sampling (n=164) of soil properties measured over the island of Pianosa (Central Italy). Statistical analysis assessing the relationship between soil properties and ecosystem features revealed that the conceptual model of ecosystems defined on the basis of environmental features such as vegetation cover, land use, and soil type was mainly related to the variation of soil organic carbon (OC) content and to the type of Mediterranean environment. The distribution of ecosystems was used to improve the accuracy of soil OC maps obtainable by a simple interpolation approach (ordinary kriging). Substantial improvement was obtained by: (i) stratification into ecosystem types and (ii) applying locally calibrated regressions to satellite imagery that introduced both inter-ecosystem and intra-ecosystem information linked to vegetation features. This study showed that interpolation methods using information on ecosystem distribution can produce accurate maps of soil OC in Mediterranean environments, mostly because of the linkage between soil OC and vegetation types, which are spatially fragmented and heterogeneous.     

Degradation and decolorization of a biodegradable-resistant polymeric dye by chelator-mediated Fenton reactions

Chelator-mediated Fenton reactions (CMFRs) were used to decolorize a biodegradable-resistant polymeric dye (Poly R-478). Screening of different iron chelators was performed on Fe(3+)-reduction activity. All chelators showed Fe(3+)-reduction activity over a wide range of pH (2-7) and each mol of catecholate chelators (3,4-dihydroxiphenilacetic acid--DOPAC and 2,3-dihydroxibenzoic acid--DHBA) reduced about 5-6 moles of Fe(3+) whereas hydroxamate chelators (acetohydroxamic acid-AHA and desferrioxamine B-DFB) reduced Fe(3+) stoichiometrically. The most effective decolorization of Poly R-478 was achieved by CMFR using catecholate chelators. In addition, a 2(4) factorial design was performed with the aim of evaluating the effects of the variables considered in this study (pH, [DOPAC], [Fe(3+)] and [H(2)O(2)]) and optimizing the dye decolorization, using response surface methodology. Statistical analysis of results showed that, in the range studied, except for Fe(3+), all variables have a significant effect on dye decolorization. A second-order model is proposed to represent the Poly R-478 decolorization. At optimum conditions, complete decolorization of the dye (degradation of the chromophoric group) and also complete chemical degradation of the dye was observed.     

Exploring Environmental Data in a Highly Immersive Virtual Reality Environment

Geography inherently fills a 3D space and yet we struggle with displaying geography using, primarily, 2D display devices. Virtual environments offer a more realistically-dimensioned display space and this is being realized in the expanding area of research on 3D Geographic Information Systems (GISs). Traditionally, a GIS has only limited tools for statistical analysis, and 3D GIS research has concentrated on the visualization of the geographical terrain. Here we discuss linking multivariate statistical graphics to geography in the highly immersive C2 virtual reality environment at Iowa State University using mid-Atlantic streams data.     

The European Water Framework Directive: Water Quality Classification and Implications to Engineering Planning

The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission–water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach - at least on a temporary basis.     

210Pb geochronology and trace metal fluxes (Cd, Cu and Pb) in the Gulf of Tehuantepec, South Pacific of Mexico

Distributions of Al, Cd, Cu, Fe, Li, Mn and Pb were analyzed in a sediment core collected in the Gulf of Tehuantepec, an important fisheries region located in the South Pacific of Mexico, where data on metal accumulation and accretion rates were previously almost nonexistent. Depth profiles of metal concentrations were converted to time-based profiles by using a 210Pb-derived vertical accretion rate, estimated to be 0.05 cm year(-1) on the average. Sediments were dated up to 8 cm depth, corresponding to a layer of ca. 140 years old. The historical changes of metal accumulation along the sediment core have shown a moderate enrichment of Cd, Cu and Pb concentrations at present, of about threefold the corresponding background concentrations. Chronological trace metal records showed that metal fluxes have increased over the last 20 years, reaching the maximum values at present of 2.5, 22.5 and 45.8 (microg cm(-2) year(-1)) for Cd, Pb and Cu, respectively. These increments in metal fluxes are likely influenced by the development of anthropogenic land-based activities since over this period of time oil production activities in the region have had a significant development.     

Determining subsampling effort for the development of a rapid bioassessment protocol using benthic macroinvertebrates in streams of Southeastern Brazil

The purpose of this study was to establish a subsampling procedure for benthic macroinvertebrates to aid in the development of a multimetric index to assess the biological condition of streams. Data from six streams that are considered minimally impaired were used. Subsampling was done using a device divided into 24 quadrats. The sediment from each quadrat was sorted, and all organisms were removed and identified. Richness metrics were the most affected by subsample size. Relative-abundance metrics were the most stable, proving that the sample was well distributed throughout the tray and abundance proportions were maintained. The results showed that the macroinvertebrate assemblage present in the six quadrats was similar to that present in the full sample. These analyses indicated that six quadrats, randomly designated, with a minimum of 200 collected specimens could be used in place of the full sample. In routine water management, managing time and costs are a major challenge; therefore, this type of simplification is absolutely necessary to ensure that a biomonitoring tool is useful for practical applications.     

Little Egret (Egretta garzetta) as a bioindicator of trace element pollution in Tunisian aquatic ecosystems

The Little Egret, Egretta garzetta, has breeding colonies in the island of Chikly (in the lake of Tunis) and in Thyna saltpans (in the gulf of Gabès), two important Tunisian wetlands that are strongly affected by anthropogenic activity. Here, we used E. garzetta chick feathers for environmental monitoring of breeding grounds of this species. Since trophic ecology is fundamental when interpreting contamination levels, our approach combined both trace-element (Hg, Pb, Cd, and Se) and stable-isotope analysis of ??¹³C, ??¹⁵N, and ??³⁴S. Hg, Se, and ??¹⁵N levels were higher in specimens collected on Chikly than in Thyna. These observations highlight the degree of eutrophication of the lake of Tunis. Yellow-legged gulls (Larus michahellis) breeding in the same areas also feeds in the lake and attains similar concentrations of Hg and Se. In Thyna, egrets and gulls exploit distinct foraging habitats, as demonstrated by stable isotope analysis. The highest Hg and Se concentrations were found in Thyna. This result is consistent with greater exploitation of marine resources from the gulf of Gabès.