Land use and the spatial distribution of perfluoroalkyl compounds as measured in the plasma of bottlenose dolphins (Tursiops truncatus)

The distribution of perfluoroalkyl compounds (PFCs) in the environment is well documented with higher concentrations observed in wildlife located in industrial and urban areas. This study examined the distribution of PFCs in relation to land use using blood samples collected from bottlenose dolphins during capture-release health assessment surveys conducted in Charleston, SC. The study area was partitioned into three subareas (ACW, CHS, and SRE) based upon habitat and land use characteristics. The ACW and CHS subareas are characterized by high degrees of industrial and urban land uses, while the SRE subarea is more residential and characterized by a lower degree of developed land use. Long-term monitoring data from photo-identification surveys were used to group bottlenose dolphins based on their proportions of sightings in the different subareas. Dolphins affiliated with both the ACW and CHS subareas were observed to have significantly higher mean plasma concentrations of perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) than those affiliated with the SRE subarea. Dolphins affiliated with the ACW subarea were found to have a significantly higher mean plasma concentration of PFUnA than those affiliated with the CHS subarea. Further examination of the distribution of the PFCs revealed positive correlations with developed land uses and negative correlations with wetland/marsh land cover. A positive correlation was also observed between PFUnA and agricultural land use. The variability and scale of the observed contaminant burdens have important implications for the conservation and management of living marine resources and illustrates the importance of long-term monitoring of free-ranging wildlife species.     

厦门东海域鱼类食物网研究

本文分析了厦门东海域58种鱼类的营养关系.根据对它们的食性分析,并依其食料生物的生态类群,将厦门东海域的鱼类食性类型分为:浮游生物食性、底栖生物食性、游泳动物食性、浮游生物和底栖生物、底栖生物和游泳动物食性等5种.该海域鱼类的营养级可分为4级:杂食性鱼类、低级肉食性鱼类、中级肉食性鱼类和高级肉食性鱼类,其中低级肉食性鱼类占优势,为63.79%.本文还分析了厦门东海域鱼类的食物网及其能量流动途径,并提出合理利用和保护厦门东海域鱼类资源的建议.     

GIS Investigation of the relationship of sex and season on the population distribution of common bottlenose dolphins (Tursiops truncatus) in Charleston,South Carolina

ABSTRACT

The Charleston Estuarine System Stock (CESS) of common bottlenose dolphins (Tursiops truncatus) has been the focus of population monitoring for the past 20 years. Photo-id studies have determined abundance and survival estimates for this population, which exhibits high site fidelity in this area. However, fine-scale distribution, utilization patterns, and the driving forces behind these patterns are lacking. Using historical photo-id data and a novel application of geographic information system (GIS) analysis, the present study identified core use areas within Charleston Harbor, as well as patterns specific to sexes and seasons. Photo-id data of 319 dolphins sighted 11 times or more during 2004–2009 were analyzed. Heat maps were developed to examine spatial distributions using kernel density estimates (KDE) and were compared between sexes and seasons. Multiple high-density core use areas were identified for this population, with the most noteworthy near the mouth of the harbor toward the Atlantic Ocean. Fine-scale distribution varied across sexes, as well as seasons. Some areas were identified as more specifically inhabited by one sex, while other areas overlapped between sexes. Females were more tightly concentrated within their distribution while males were more dispersed. Although population distribution varied across seasons, sex distributions remained.     

Assessment of perfluorinated compounds (PFCs) in plasma of bottlenose dolphins from two southeast US estuarine areas: relationship with age, sex and geographic locations

Plasma PFCs were measured in 157 bottlenose dolphins (Tursiops truncatus) sampled from two US southeast Atlantic sites (Charleston (CHS), SC and Indian River Lagoon (IRL), FL) during 2003-2005. ∑PFCs, perfluoroalkyl carboxylates (∑PFCAs), perfluoroalkyl sulfonates (∑PFSAs) and individual compounds were significantly higher in CHS dolphins for all age/sex categories compared to IRL dolphins. Highest ∑PFCs concentrations occurred in CHS juvenile dolphins (2340 ng/g w.w.); significantly higher than found in adults (1570 ng/g w.w. males; 1330 ng/g w.w. females). ∑PFCAs were much greater in CHS dolphins (≈ 21%) compared to IRL dolphins (≈ 7%); ∑PFSAs were 79% in CHS dolphins versus 93% in IRL dolphins. PFOS, the dominant compound, averaged 72% and 84%, respectively, in CHS and IRL dolphins. Decreasing PFC levels occurred with age on the bioaccumulation of PFCs in both sites. These observations suggest PFC accumulation in these two dolphin populations are influenced by site-specific exposures with significantly higher levels in CHS dolphins.     

准噶尔盆地复杂地区地层压力预测方法研究及应用

准噶尔盆地地层压力分布复杂,长期以来由于地层压力预测不准,在钻井过程中常出现井壁失稳、卡钻、井壁坍塌、钻井液漏失等工程事故,严重影响了钻井速度.为减少工程复杂问题,准确预测地层压力至关重要.为此,在准噶尔盆地开展了断层相关褶皱理论解释复杂构造、利用地质构造建模指导速度建模,求出每层的层速度和真倾角,再用Terzaghi 理论计算地层孔隙压力,计算结果证实地层压力预测精度显著提高.     

Crystal Structure and Chemical Composition of Ludwigite from Vranovac Ore Deposit (Boranja Mountain,Serbia)

The crystal structure of ludwigite from Vranovac ore deposit (Boranja Mt., Serbia) was refined using the X-ray powder diffraction (XRPD) Rietveld method in the space group Pbam to a final RB=7.45% and RF=5.26%. It has the unit cell dimensions of: a=9.2515(2) ?; b=12.3109(2) ?; c=3.03712(7) ?; and V=345.91(1) ?3. The calculated distances and angles are mostly in good agreement with the Mg2+-Fe2+ substitutions across the M(1) and M(3) sites, as well as with the Fe3+-Al3+ replacement in the M(4) site. However, the mean observed M(2)-O distance is considerably shorter than prescribed, due to a slight increase of the Fe3+ content in the M(2) site. Such replacement was compensated by slight increase of the Fe2+ content in the M(4) site, resulting in the (Mg1.48Fe2+0.46Fe3+0.05Mn0.02)2.01(Fe3+0.94Fe2+0.04Al0.02)1.00B1.00O5 composition. The formation temperature was estimated to be about 500–600°C. The influences of the various chemical compositions to the crystallographic parameters, M-O distances, M(3) and M(4) sites shift, distortion parameters and estimated valences, were also studied and compared with other reference samples.     

Seas under ice: Stability of liquid-water oceans within icy worlds

The present-day existence of internal oceans under the outer ice shell of several icy satellites of the Solar System has been recently proposed. The presence of antifreeze substances decreasing ice’s melting point (and tidal heating in Europa’s case) has been generally believed to allow the stability of such oceans; limited cooling of the water (ice plus liquid) layer, due to stability against convection or to stagnant lid convection in the icy shell, have been also considered. Here we propose that even pure liquid-water oceans could survive today within several icy worlds, and we consider some factors affecting thermal modeling in these bodies. So, the existence of such oceans would be a natural consequence of the physical properties of water ice, independently from the addition of antifreeze substances or any other special conditions. The inclusion of these substances would contribute to expand the conditions for water to stay liquid and to increase ocean’s volume.