Short-term variability of multiple biomarker response in fish from estuaries: Influence of environmental dynamics

Short-term variability in biomarker responses and the effects of temperature and salinity variation were explored in three fish species (Dicentrarchus labrax, Solea senegalensis and Pomatoschistus microps) occurring in the Tejo estuary. Short-term variability in biomarkers was observed in all species although no pattern was discerned over time (days to weeks). Antioxidant enzymes activity (superoxide dismutase (SOD) and catalase (CAT)) showed low temporal variability, indicating some constancy or baseline level in antioxidant responses. Only CAT activity in S.?senegalensis was correlated with temperature, suggesting that exposure to contaminants triggered antioxidant acclimation. Higher short-term variability was observed in xenobiotic biotransformation enzymes activity (phase I ethoxyresorufin O-deethylase (EROD) and phase II glutathione S-transferase (GST)). Yet a significant correlation between EROD and GST in D.?labrax and S.?senegalensis suggests a concomitant response to contaminants. Moreover the lack of correlation between xenobiotic biotransformation enzymes and abiotic variables on concordant time scales, suggest a high specificity of these biomarkers to chemical exposure, rather than high variability due to environmental dynamics.     

The effect of artificial feed on blood biochemistry profile and liver histology of wild saddled bream, Oblada melanura (Sparidae)

Floating fish farms attract a great number of wild fish species, changing their behaviour and physiology. The saddled bream, Oblada melanura, sampled from populations aggregated around the Adriatic fish farm and from natural/control populations, were analysed for differences in eleven blood biochemistry parameters and liver histomorphology. The levels of lactate dehydrogenase (LDH), alkaline phosphatase (ALKP) and urea (URE) in cage-associated saddled bream (428.00±SD 321.56 U/L, 86.13±SD 39.87 U/L and 0.05±SD 0.16 mmol/L, respectively) were significantly lower than those observed in the control specimens (1047.06±SD 505.56 U/L, 125.75±SD 34.70 U/L and 1.99±SD 0.73 mmol/L, respectively). In contrast to that, concentrations of aspartate aminotransferase (AST) in cage-associated fish (87.63±SD 132.34 U/L) were higher than values noted for the control population (6.55±SD 5.90 U/L). URE and AST presented the main variables contributing to the discrimination between two analysed populations. One-way ANOSIM based on the blood parameters showed significant difference between saddled bream that fed around cages and those from the remote waters (R=0.697; P < 0.01). Hepatocytes of cage-associated fish contained large cytoplasmatic clear spaces indicating excessive accumulation of fat in the hepatocyte cytoplasm. All observed differences can be attributed to contrasting feeding behaviour of sampled populations but basic nutritional differences between them should be quantified in the future. Moreover, further research is necessary to detect their impact on the health status of the fish.     

A hydrochemical and dye- tracing investigation in the Posht-e-Naz Karstic Aquifer, Alburz Mountain, Northern Iran

A hydrochemical and tracer study (uranine injection) was conducted in Jurassic limestone of the Posht-e-Naz area in the Alborz belt to evaluate hydraulic relations between a large diameter (about 100 m) sinkhole and springs and aquifer parameters. A main goal of the project was to find out the source of turbidity of the Emarate drinking water supply spring (SP4) in rainy season. Springs discharge were measured and hydrochemical investigation were carried out. The uranine tracer was injected and eight springs, three wells and the Neka River were selected and totally 989 samples in 107 days were collected. Hydrochemical data demonstrated a relative connection between sinkhole (Sh1) and spring (SP4). The results of the tracing by sampling water indicated only a hydraulic connection between Sange- Nou spring (SP8) and injection point, while the charcoal packets analysis revealed tracer exits from spring numbers SP1, SP3, SP4, SP5, SP8, in wells W1 and W2, and in the Neka River. The concentration — time curves of charcoal packets for qualitative analysis and exit tracer for quantitative analysis is also assessed.     

Geological and Geochemical Characterization of Iron-titanium Mineral Indices in the Tertiary Anorogenic Complex of Bana (Cameroon Volcanic Line)

Please?refer?to?the?attachment(s)?for?more?details.     

Nitrogen loading to Pleasant Bay, Cape Cod: application of models and stable isotopes to detect incipient nutrient enrichment of estuaries

To test and refine methods to detect nutrient enrichment and resulting eutrophication, we applied the Waquoit Bay nitrogen loading model (NLM) and Estuarine loading model (ELM) to estuaries of Pleasant Bay that receive increasing but low N loads (25-199 kg N ha(-1) yr(-1)) from land. Contributions of wastewater to these estuaries increased from 7% to 63% as N loads increased, and modeled estimates of dissolved inorganic nitrogen in the water were within approximately 27% of measured values. N isotopic signatures in suspended and benthic organic matter and in tissue of quahogs increased as wastewater contributions to N loads increased, with clams approximately 4 per thousand heavier than organic matter, indicating that even at these low N loads, N from land-derived sources moved detectably up the food web. These results extend the application of NLM and ELM to detect incipient levels of N enrichment and demonstrate that these models can be used in conjunction with isotope measurements as the basis for food web analyses in a system exposed to relatively lower N loads than previously studied.     

印度中部MaДЖГaBaH金刚石岩管的物质成分特征

本文报道MaДЖГaBaH（印度中部）火山岩管含金刚石岩石的综合研究结果，首次分析了这个岩管岩石中的金云母、蛇纹石、硫化物的成分。按成分MaДЖГaBaH岩管的岩石实际上完全缺乏碳酸盐物质，TiO2和P2O5含量较高，含有高钛金云母和指示矿物（镁名榴石、铬铁矿、钛铁矿）含量低而不同于典型的金伯利岩。同时这种岩石与含钾镁煌斑岩也有显著差别：含K2O很低（0．46－1．79％），没有发现单斜辉石、钾碱镁闪石。这种岩石似乎是金伯利岩和钾美煌斑岩之间的过渡类型。