Floating marine debris in coastal waters of the SE-Pacific (Chile)

Herein we report on the abundance and composition of floating marine debris (FMD) in coastal waters of the SE-Pacific (off the Chilean coast) during the austral summer 2002. The observed FMD consisted mainly of plastic material (86.9%). Densities of FMD were highest between 20 degrees S and 40 degrees S, corresponding to the main concentrations of human population and activities. Low densities of FMD were found in the south between 40 degrees S and 50 degrees S (<1 item km(-2)). Generally, the highest densities were recorded in nearshore waters of major port cities (>20 items km(-2)), but occasionally high concentrations of debris were also found 50 km offshore. Densities of FMD in coastal waters of the SE-Pacific are of similar magnitudes as those found in coastal waters or inland seas of highly populated regions in the northern hemisphere, indicating the need for improved regulation and legislation in the countries of the SE-Pacific.     

Effects of spilled oil on microbial communities in a tidal flat

Effects of spilled oil on microbial communities in tidal flats were examined by use of a simulator for a tidal flat ecosystem. The simulator is composed of a wave generator, a tide control device, and a tidal flat. Sediment for the tidal flat was obtained at a natural tidal flat in Hiroshima Bay, Japan. After stabilizing the benthic organisms, fuel oil C was added to the surface of the flat at 1 lm(-2). Although the total number of micro-organisms remained at 1.5-3.5 x 10(9) cells g(-1) dry sediment irrespective of the addition of oil, bacterial communities which were analyzed based on the 16S rDNA showed clear changes after the addition of fuel oil C and after a subsequent recovery period. Bacterial colonies were randomly isolated from the oil-supplemented sediment during the experiments, and the isolates were examined for susceptibility to hydrocarbons in order to screen the oil-susceptible bacteria. The proportion of oil-susceptible bacteria in the isolates decreased with the addition of the oil. Oil-susceptible bacteria showed an inability to assimilate petroleum compounds as well as an inhibition of growth. The possibility of using oil-susceptible bacteria as an indicator of bioremediation in tidal flats was discussed.     

Persistent organochlorine residues in sediments from the Black Sea

The extent of contamination of the Black Sea by selected organochlorine compounds has been assessed through the analysis of surficial sediments taken from throughout the region. Concentrations of HCHs at sites influenced by the Danube delta are among the highest recorded on a global basis (up to 40 ng g(-1) dry wt). The ratio between the alpha- and gamma-isomers was relatively low indicating contamination through the use of lindane. Concentrations of DDTs (0.06-72 ng g(-1) dry wt) and PCBs (0.06-72 ng g(-1) dry wt) were not especially high in comparison to levels reported from throughout the world. The DDE/DDT ratio was, however, low indicating fresh inputs and hence current usage of DDT within the Black Sea region.     

科学园作为区域政策工具的评价

引言这几年,科学园(scrence park)或研究园(research park),技术园(technology park),已变成越来越流行的以技术为基础的区域政策的工具。1982年以来,美国科学园的数目已增加到几乎3倍,至今增长势头还在继续。孟克(C.S.P.Monck)等人1988年也提供了自从80年代初以来英国科学园发展“第二次浪潮”的文件。要弄清科学园目前的数目很困难,因为几乎每周都有新园宣告成立,而所新建科学园的失败率却是非常高的。科学园的激增引起一些明显的公共政策问题。     

可能蒸发与地区蒸发间的互补关系

本文中的地区蒸发定义为一个很大区域的蒸散,满足这种区域条件是其蒸散对过境空气的温湿状况发生影响。可能蒸发有许多定义,这里所用的是科科勒和帕米利对彭曼公式进行修正后,根据气候观测资料估算的蒸发,即E_p=DR_A+(1-D)f_A(V-V_D)(1)式中,E_P-可能蒸发,R_A-地面温度为气温时的净辐射,f_A-水汽传输系数,V和V_D分别为气温和露地温度时的饱和水汽压,D=(1+λ/△)~(-1),△-饱和水汽压相对于气温的变     

Calcium alginate immobilized marine microalgae: experiments on growth and short-term heavy metal accumulation

Growth of 11 calcium alginate immobilized marine microalgal species belonging to eight taxonomical groups has been checked in the present work. Cellular densities inside the calcium alginate beads were monitored during 17 days. Good growth and maintenance of the structure of the beads were both found for some of the assayed species. One of those species (Tetraselmis chui, Prasinophyceae) was selected in order to perform a short term (up to 24 h) heavy metal accumulation experiment. Beads of calcium alginate containing (or not) cells of T. chui were exposed to 820 μg L⁻¹ Cu and 870 μg L⁻¹ Cd separately during a 24 h period, and accumulation of heavy metals in the beads was measured after this time and compared. Concentration of each metal in the supernatants was monitored at 5, 10, 60 min and 24 h from the beginning of the experiment. After 24 h, practically all Cu was removed by the beads. Beads with immobilized algae removed around 20% of total Cd, while beads without algae removed half of that percentage.     

Trace element accumulation in fishes collected from coastal waters of the Caspian Sea

Concentrations of 13 trace elements (V, Mn, Cr, Co, Cu, Zn, Se, Mo, Ag, Cd, Hg, Tl and Pb) were determined in muscle of bony fishes collected from coastal areas of the Caspian Sea (Kazakhstan, Azerbaijan, Turkmenistan and Iran). In all the fishes, Zn concentration was highest, followed by Cu, Se, Mn and Co, while levels of toxic elements (Ag, Cd, Cd, Tl and Pb) were relatively low. Concentrations of several elements were significantly varied between the species in each sampling area. For most of the trace elements examined, the concentrations decreased significantly with body weight of fishes. In contrast, a positive correlation with body weight was found for Co, Se and Pb concentrations in one fish species, and Hg in 2 fish species. Geographical difference in the concentrations of trace elements was examined using the Caspian roach collected from five stations of Iranian coastal waters. The concentrations of Co, Mo, Ag, Cd and Tl were higher in fishes from western stations than those from eastern stations, whereas the opposite trend was observed for Hg, indicating that local sources of trace metal pollution may be present in the Iranian coastal areas of the Caspian Sea. Levels of trace elements in Caspian fishes were relatively low in comparison to those of other regions, but Zn and Hg levels in some specimens exceeded the guideline values for food.     

Benthic diatom community response to environmental variables and metal concentrations in a contaminated bay adjacent to Casey Station, Antarctica

This study examined the effects of anthropogenic contaminants and environmental variables on the composition of benthic diatom communities within a contaminated bay adjacent to an abandoned waste disposal site in Antarctica. The combination of geographical, environmental and chemical data included in the study explained all of the variation observed within the diatom communities. The chemical data, particularly metal concentrations, explained 45.9% of variation in the diatom communities, once the effects of grain-size and spatial structure had been excluded. Of the metals, tin explained the greatest proportion of variation in the diatom communities (28%). Tin was very highly correlated (R2>0.95) with several other variables (copper, iron, lead, and sum of metals), all of which explained similarly high proportions of total variation. Grain-size data explained 23% of variation once the effects of spatial structure and the chemical data had been excluded. The pure spatial component explained only 1.8% of the total variance. The study demonstrates that much of the compositional variability observed in the bay can be explained by concentrations of metal contaminants.