Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis

This study investigated the effects of seawater pH (i.e., 8.10, 7.85 and 7.60) and temperature (16 and 19 °C) on (a) the abiotic conditions in the fluid surrounding the embryo (viz. the perivitelline fluid), (b) growth, development and (c) cuttlebone calcification of embryonic and juvenile stages of the cephalopod Sepia officinalis. Egg swelling increased in response to acidification or warming, leading to an increase in egg surface while the interactive effects suggested a limited plasticity of the swelling modulation. Embryos experienced elevated pCO₂ conditions in the perivitelline fluid (>3-fold higher pCO₂ than that of ambient seawater), rendering the medium under-saturated even under ambient conditions. The growth of both embryos and juveniles was unaffected by pH, whereas ⁴⁵Ca incorporation in cuttlebone increased significantly with decreasing pH at both temperatures. This phenomenon of hypercalcification is limited to only a number of animals but does not guarantee functional performance and calls for better mechanistic understanding of calcification processes.     

Seasonal decline in reproductive performance varies with colony size in the fairy martin, <Emphasis Type="Italic">Petrochelidon ariel</Emphasis>

Reproductive success within populations often varies with the timing of breeding, typically declining over the season. This variation is usually attributed to seasonal changes in resource availability and/or differences in the quality or experience of breeders. In colonial species, the timing of breeding may be of particular importance because the costs and benefits of colonial breeding are likely to vary over the season and also with colony size. In this study, we examine the relationship between timing of breeding and reproductive performance (clutch size and nest success) both within and between variable sized colonies (n = 18) of fairy martins, Petrochelidon ariel. In four of these colonies, we also experimentally delayed laying in selected nests to disentangle the effects of laying date and individual quality/experience on reproductive success. Within colonies, later laying birds produced smaller clutches, but only in larger colonies. The general seasonal decline in nest success was also more pronounced in larger colonies. Late laying birds were generally smaller than earlier laying birds, but morphological differences were also related to colony size, suggesting optimal colony size also varies with phenotype. Experimentally delayed clutches were larger than concurrently produced non-delayed clutches, but only in larger colonies. Similarly, delayed clutches were more likely to produce fledglings, particularly later in the season and in larger colonies. We suggest that the reduced performance of late breeding pairs in larger colonies resulted primarily from inexperienced/low quality birds preferring to settle in larger colonies, possibly exacerbated by an increase in the costs of coloniality (e.g., resource depletion and ectoparasite infestations) with date and colony size. These findings highlight the importance of phenotype-related differences in settlement decisions and reproductive performance to an improved understanding of colonial breeding and variation in colony size.     

Vertical distribution of polycyclic aromatic hydrocarbons (PAHs) in Hunpu wastewater-irrigated area in northeast China under different land use patterns

The concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in groundwater and soil profiles from upland field and paddy field in the Hunpu wastewater-irrigated area of northeast China. In the study area, the peak concentrations of total PAHs were within or just below the topsoil, and the contents decline with depth at various trend verified by the Spearman's rank correlation test. The total PAH concentrations in upland soil layers ranged from 46.8 to 2,373.0 microg/kg (dry wt.), while the concentrations in paddy soil layers ranged from 23.1 to 1,179.1 microg/kg (dry wt.). The 16 priority PAHs were all detected in the analyzed soil samples, and naphthalene (Nap), phenanthrene (Phe), fluoranthene (Fla), chrysene (Chr), and benzo[a]pyrene (Bap) were selected for further study in terms of their vertical distributions. The concentrations of both total and individual PAHs in upland soil were generally higher than those in the corresponding layers of paddy soil. The concentrations of total and individual PAH were notably different between the corresponding horizons in upland and paddy soil were probably attribute to the different sources and properties of the PAHs and soil; different methods of soil tillage and plant growing. Special PAH compound ratios, such as phenanthrene/anthracene, fluoranthene/pyrene, LMW/HMW, and parent PAH ratios (Ant/178, Fla/202, BaA/228, and Ilp/276) were used to identify the source of soil PAHs. The data suggests that the possible sources of PAHs in the Hunpu wastewater-irrigation area are the incomplete combustion of coal, petroleum and crude oil, automobile exhausts. These sources lead to pollution of the soil and groundwater by wet/dry deposition and vertical downward migration.     

醇和酚类污染物对欧洲林蛙蝌蚪及梨形四膜虫毒性的定量结构-活性模型

醇和酚类等有机化合物作为重要的工业原料,广泛应用于医药卫生、有机合成、食品工业等领域,但生产中排放于环境的这些物质,会对生物造成一定的毒性作用。为建立包含醇和酚类有机污染物对欧洲林蛙蝌蚪及梨形四膜虫毒性的定量结构-活性相关性模型,计算了227种有机污染物的分子连接性指数和分子形状指数,优化筛选了分子连接性指数的0X、1X、2X、4X和5Xc、分子形状指数的K1和K2共7种参数,将这7种结构参数作为神经网络输入层变量,110种有机污染物对欧洲林蛙蝌蚪的毒性值作为输出层变量,采用7:8:1的网络结构方式,构建了令人满意的对欧洲林蛙蝌蚪毒性的神经网络预测模型,方程总相关系数r为0.988,毒性预测值与实验值之间的平均误差为0.14。为检验指数的普适性,同样用这7个结构参数与117种醇和酚类化合物对梨形四膜虫的毒性进行分析,所得神经网络模型的总相关系数达到0.997,对梨形四膜虫毒性的预测值与实验值之间的平均误差仅为0.065,结果表明,所建模型具有良好的预测有机污染物对林蛙蝌蚪及梨形四膜虫急性毒性的能力。     

Atmospheric trace element concentrations in total suspended particles near Paris,France

To evaluate today’s trace element atmospheric concentrations in large urban areas, an atmospheric survey was carried out for 18 months, from March 2002 to September 2003, in Saclay, nearby Paris. The total suspended particulate matter (TSP) was collected continuously on quartz fibre filters. The TSP contents were determined for 36 elements (including Ag, Bi, Mo and Sb) using two analytical methods: Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The measured concentrations were in agreement within the uncertainties with the certified values for the polycarbonate reference material filter SRM-2783 (National Institute for Standard Technology NIST, USA). The measured concentrations were significantly lower than the recommended atmospheric concentrations. In 2003, the Pb atmospheric level at Saclay was 15 ng/m³, compared to the 500 ng/m³ guideline level and to the 200 ng/m³ observed value in 1994. The typical urban background TSP values of 1–2, 0.2–1, 4–6, 10–30 and 3–5 ng/m³ for As, Co, Cr, Cu and Sb, respectively, were inferred from this study and were compared with the literature data. The typical urban background TSP concentrations could not be realised for Cd, Pb and Zn, since these air concentrations are highly influenced by local features. The Zn concentrations and Zn/Pb ratio observed in Saclay represented a characteristic fingerprint of the exceptionally large extent of zinc-made roofs in Paris and its suburbs. The traffic-related origin of Ba, Cr, Cu, Pb and Sb was demonstrated, while the atmospheric source(s) of Ag was not identified.     

Air pollutants in rural homes in Guizhou,China – Concentrations,speciation, and size distribution

Several types of fuels, including coal, fuel wood, and biogas, are commonly used for cooking and heating in Chinese rural households, resulting in indoor air pollution and causing severe health impacts. In this paper, we report a study monitoring multiple pollutants including PM₁₀, PM_2.5, CO, CO₂, and volatile organic compounds (VOCs) from fuel combustion at households in Guizhou province of China. The results showed that most pollutants exhibited large variability for different type of fuels except for CO₂. Among these fuels, wood combustion caused the most serious indoor air pollution, with the highest concentrations of particulate matters (218～417 μg m^?3 for PM₁₀ and 201～304 μg m^?3 for PM_2.5), and higher concentrations of CO (10.8 ± 0.8 mg m^?3) and TVOC (about 466.7 ± 337.9 μg m^?3). Coal combustion also resulted in higher concentrations of particulate matters (220～250 μg m^?3 for PM₁₀ and 170～200 μg m^?3 for PM_2.5), but different levels for CO (respectively 14.5 ± 3.7 mg m^?3 for combustion in brick stove and 5.5 ± 0.7 mg m^?3 for combustion in metal stove) and TVOC (170 mg m^?3 for combustion in brick stove and 700 mg m^?3 for combustion in metal stove). Biogas was the cleanest fuel, which brought about the similar levels of various pollutants with the indoor case of non-combustion, and worth being promoted in more areas. Analysis of the chemical profiles of PM_2.5 indicated that OC and EC were dominant components for all fuels, with the proportions of 30～48%. A high fraction of SO₄^2? (31～34%) was detected for coal combustion. The cumulative percentages of these chemical species were within the range of 0.7～1.3, which was acceptable for the assessment of mass balance.     

Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells

The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb²⁺, Cd²⁺ and Zn²⁺ from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent’s dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent.     

Seasonal variability of antioxidant biomarkers and energy reserves in the freshwater gammarid Gammarus roeseli

In gammarids, behavioural and biochemical biomarkers are commonly used in ecotoxicological studies. In our study, we have investigated seasonal variations of several biochemical biomarkers in Gammarus roeseli, a freshwater species. Organisms were sampled monthly over a 1-year period. Gender was distinguished to measure antioxidant enzyme activities like total glutathione peroxidase (GPxtot), selenium-dependent glutathione peroxidase (SeGPx) and catalase enzymes, lipoperoxidation end-product (malondialdehyde, MDA), and energy reserves with protein and lipid contents. In the same time, usual water physico-chemical parameters were measured at the sampling site. A based-gender difference was observed for parameters related to oxidative stress. Females showed higher antioxidant enzyme activities and lower MDA level than males. Parameters related to oxidative stress and energy reserves appeared correlated with temperature and physiological status of organisms. Females GPx activities were lower in autumn and winter when no breeding occurred. In both gender, MDA levels were correlated with temperature with an increase of lipoperoxidation in summer. Lipid contents were the lowest in summer and the highest in winter, probably due to the reproductive status of organisms and their feeding behaviour. Gender-based differences of biochemical parameters suggest a specific sensitivity of males and females in ecotoxicological experiments. Moreover, organisms could be more vulnerable in summer when MDA levels are high and energy reserves low. Deleterious effect of xenobiotics would be different with gender and season.