Investigations into the bioavailability and bioaccumulation of mercury and other trace metals to the sea cucumber, Sclerodactyla briareus, using in vitro solubilization

The in vitro solubilization and bioaccumulation of mercury and other trace metals by the intestinal fluid of the sea cucumber, Sclerodactyla briareus, was investigated. Sediments were incubated with intestinal fluid and the intestinal fluid was analyzed for the in vitro experiments. Experiments examined both procedural effects of in vitro solubilization and bioaccumulation of trace metals by the sea cucumber. Both solubilization and bioaccumulation were compared among the different metals. This comparison revealed that monomethylmercury (MMHg) solubilization and bioaccumulation is greater than Hg_I; Cd solubilization is higher than MMHg and Hg_I; and Cu and Pb solubilization is similar to MMHg and slightly higher than Hg_I. Solubilization and bioaccumulation was found to be very low, except for Cd, which had high relative solubilization but low bioaccumulation. It was concluded that while solubilization could be the rate-limiting step for certain metals, other factors, such as depuration and membrane transport, may influence overall bioaccumulation of the other metals.     

地质雷达在加拿大曼尼托巴省皮纳瓦怀特谢尔研究区深成岩断裂…

在加拿大核废料处理计划中，地质雷达（ＧＰＲ）已经用来测绘加拿大地质花岗岩和片麻岩内的构造特征，野外结果进一步证实了理论上的分析，在含有淡水或稀释地下不的近地表低电导率的岩石中，信号的用穿透工超过６０ｍ是可能的，在更大的深度上（大于４００ｍ）由于与地盐质地耳水有关的电导率的升高，其有效探查距离急剧下降（低于２０ｍ）。地质雷达已经成功地运用于钻井和露头的测线上，本文介绍了怀特谢尔（ＷｈｉｔｅＳｈｅｌｌ     

“94·7"北京大暴雨的能量锋及能量锋生

首先利用湿静力湿度Ｔσ分析了１９９４年７月１２－１３日北京地区台风低压和西来槽共同影响的强降水过程的能量场，其次利用能量锋锋生方程组，并进行能量锋锋生分析。结果表明：此次降水过程对流层低层对应有明显的Ｔσ水平能量锋区，且Ｔσ能量锋区与同时次６小时降水相对应。能量锋生方程组计算出的Ｔσ水平锋生是地转变形项和倾斜项共同作用的结果，而Ｔσ垂直锋生主要是倾斜项的作用。同时，水平锋生对降水具有指示意义。     

A laboratory analog for the carrier of the 3 micron emission of the protoplanetary nebula IRAS 05341+0852

A mixture of the polycyclic aromatic hydrocarbons (PAHs), acenaphthylene and acenaphthene, when subjected to the energetic environment of a hydrogen plasma, is transformed into a material that exhibits an infrared absorption profile in the 3 micron region that is an excellent match of the protoplanetary nebula IRAS 05341+0852 emission profile in the same wavelength region. Acenaphthylene and acenaphthene were chosen as precursors in the experiment because these molecules have a structure that can be described as a keystone in a process in which carbon atoms in a stellar wind condense into PAH species. The spectral match between experiment and observations appears to validate that scenario.     

Seasonal changes in imposex and tissue burden of butyltin compounds in Thais clavigera populations along the coastal area of Mirs Bay, China

We assessed the current status of tributyltin (TBT) contamination of Thais clavigera (Gastropoda) along the coastal area of Mirs Bay, China for the first time. The snail samples were collected from 10 different sites in the summer (June) and winter (December) of 2006, respectively. They were analyzed for imposex status, i.e. relative penis size index (RPSI) and vas deferens sequence index (VDSI), followed by quantification of butyltins in their tissues. Most of the collected females suffered from imposex, but the level of butyltin contamination varied with the distance from Yantian Port, which is currently the fourth busiest container port in the world. The tissue concentration of TBT varied with season. For a particular site, the winter samples in general contained much higher concentration of TBT than the summer samples. RPSI, VDSI and organotin concentrations were higher in T. clavigera collected from sites closer to the Port, such as the Seafood Street and Kat O. Both RPSI and VDSI were positively correlated with the tissue burden of tributyltin. VDSI exhibited little seasonal variability, whereas RPSI showed marked seasonal variability, with lower values in the summer samples. The current results will serve as an important reference for long-term monitoring of butyltin contamination in this area.     

Correlations between gastropod shell dissolution and water chemical properties in a tropical estuary

Although poorly reported in the scientific literature, acidic waters characterize many South East Asian estuaries. The observation of shell dissolution in a typically marine gastropod whelk (Thais) prompted investigation into determining relationships between shell properties of this whelk and the water chemistry (including pH) of the Sungai Brunei estuary (Borneo) in which it occurs. Shell weight, shell length and topographical shell features were determined for populations of Thais gradata distributed along a gradient of pH and salinity ranging between 5.78 and 8.3 pH units, and 3.58 and 31.2psu. Shell weight varied independently of the co-varying acidity, salinity and calcium levels experienced. In contrast, shell length and a semi-quantitative variable based on shell sculpturing (shell erosion rank, SER) were significantly correlated with these water chemistry variables. This study brings attention to the potential use of estuarine organisms and systems in investigating current marine acidification questions.     

The impact of organic pollution on the macrobenthic fauna of Dubai Creek (UAE)

Dubai Creek is a tidal marine intrusion bisecting Dubai within the United Arab Emirates (UAE). The creek extends 14km inland from its opening into the Arabian Gulf, with a narrow lower creek channel leading to a lagoon section in the upper creek. The creek contains numerous sources of organic pollution including sewage outlet flows and boat waste. A survey of the creek was performed, assessing organic pollution, water properties, and the benthic macrofaunal community. The upper creek was heavily polluted with macrofauna communities commonly associated with organic pollution and eutrophication, while the lower creek contained low pollution and relatively healthy macrofauna communities. There is little net tidal flow of water within the creek and residence time in the lagoon is high, which may account for the high organic pollution levels. However, some evidence of the pollution effect moving into the lower creek was found. The results are considered in light of current and historic organic loading within the creek and future developments in the area.     

Stable isotopes as a useful tool for revealing the environmental fate and trophic effect of open-sea-cage fish farm wastes on marine benthic organisms with different feeding guilds

Environmental fate of fish farm wastes (FFW) released from an open-sea-cage farm at Kat O, Hong Kong was examined by measuring carbon and nitrogen stable isotope (SI) ratios in selected benthic organisms collected along a 2000 m transect from the farm. Our results showed that FFW significantly influenced the energy utilization profile of consumers near the fish farm. Although nitrogen enrichment effect on δ15N was anticipated in biota near the farm, the predicted patterns did not consistently occur in all feeding guilds. Two species of suspension-feeders, which relied on naturally δ15N-depleted sources, were δ15N-enriched near the fish farm. In contrast, both species of benthic grazer and deposit-feeder, which relied on naturally δ15N-enriched algal sources, were δ15N-depleted under the influence of FFW. The SI signatures of biota can, therefore, serve as feasible biomarkers for FFW discharges only when the trophic structure of the receiving environment is fully elucidated.     

Seasonal variations of imposex indices and butyltin concentrations in the rock shell Thais clavigera collected from Hong Kong waters

This study investigated butyltin contamination in Hong Kong waters using the rock shell Thais clavigera as a biomonitor. We collected rock shells from nine coastal sites in both winter 2005 and summer 2006 to examine the spatial and seasonal patterns. The relative penis size index (RPSI) and vas deferens sequence index (VDSI) were determined following a standard protocol, while the tissue concentrations of butyltins (i.e., mono-, di- and tri-butyltin) were measured using gas chromatography. The results showed that imposex was particularly severe in T. clavigera collected from Victoria Harbour, Pak Sha Wan and Sai Kung Pier where shipping activities were frequent. Both imposex indices had a positive correlation with tissue concentration of tributyltin in T. clavigera. While VDSI exhibited little seasonal variation, RPSI of winter specimens was significantly higher than that of summer specimens. Thus, sampling season should be standardised when using RPSI as a biomarker.