Determination of HBCD, PBDEs and MeO-BDEs in California sea lions (Zalophus californianus) stranded between 1993 and 2003

Blubber samples from male California sea lions (Zalphophus californianus) stranded between 1993 and 2003 were analyzed for 27 polybrominated diphenyl ether (PBDE) congeners, three isomers of hexabromocyclododecane (HBCD) and 14 methoxylated polybrominated diphenyl ether (MeO-BDE) congeners. Total PBDEs ranged from 450 ng/g to 4740 ng/g wet mass and total HBCD ranged from < 0.3 ng/g to 12 ng/g wet mass. The concentration of HBCD increased from 0.7 ng/g to12.0 ng/g wet mass in sea lion blubber between 1993 and 2003. However, no significant temporal trend was observed for any of the other brominated compounds over this 10 year period. Only one of the 14 MeO-BDE congeners was detected in the blubber samples, 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (6-MeO-BDE 47), and concentrations ranged from < 0.2 ng/g to 12 ng/g wet mass. A bromo-, chloro-heterocyclic compound, 1,1'-dimethyl-tetrabromo-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), previously reported in marine species along the Pacific coast, was also identified in the sea lion blubber. DBP-Br4Cl2 ranged from 44 ng/g wet mass to 660 ng/g wet mass and was present at concentrations rivaling the dominant PBDE congener, BDE 47 (2,2',4,4'-tetrabromodiphenyl ether). Concentrations of DBP-Br4Cl2 were positively correlated with 6-MeO-BDE 47 (r = 0.7; p < 0.05). Both of these compounds have been identified in marine algae and sponges, and studies suggest they are both produced from natural sources. This study demonstrates that brominated compounds from both anthropogenic and biogenic sources can accumulate to similar levels in marine mammals. In addition, HBCD concentrations appear to be increasing in California sea lion populations, whereas PBDE concentrations, between 1993 and 2003, were highly variable.     

Use of biliary PAH metabolites as a biomarker of pollution in fish from the Baltic Sea

During field campaigns of the BEEP project (Biological Effects of Environmental Pollution in Marine Coastal Ecosystems) in 2001-2002, metabolites of polycyclic aromatic hydrocarbons (PAHs) were determined in bile samples from three fish species, flounder (Platichthys flesus), perch (Perca fluviatilis) and eelpout (Zoarces viviparus), from four separate areas in the Baltic Sea. Two determination methods were applied: fixed wavelength fluorescence (FF) for pyrene-type metabolites and high-performance liquid chromatography with fluorescence detection (HPLC). There was a good correlation between the FF method and 1-OH pyrene determined by HPLC. Normalisation of the FF data for absorbance at 380 nm or bile protein concentrations greatly increased variance in one third and decreased it in two thirds of the cases and resulted in a loss of significant differences (protein normalisation) between the sampling stations, but normalisation of the HPLC data had little effect on the results. The biliary PAH metabolite content was usually higher in males than in females. In perch and eelpout the biliary PAH contents were at similar levels, whereas in flounder the levels were lower. The sampling areas arranged in decreasing order of biliary PAH contents were: Wismar Bay > Gulf of Gdansk > Lithuanian coast > Kvadofj?rden (reference area). It is concluded that FF with un-normalised data is a reliable and simple method for monitoring purposes and only one sex of a selected species should be used.     

Mediterranean fin whales at risk from fatal ship strikes

This paper reviews and analyzes ship collision records for the relatively isolated population of fin whales in the Mediterranean Sea from 1972 to 2001. Out of 287 carcasses, 46 individuals (16.0%) were certainly killed by boats. The minimum mean annual fatal collision rate increased from 1 to 1.7 whales/year from the 1970s to the 1990s. Fatal strike events (82.2%) were reported in or adjacent to the Pelagos Sanctuary, characterized by high levels of traffic and whale concentrations. Among 383 photo-identified whales, 9 (2.4%) had marks that were attributed to a ship impact. The reported rates are unusually high for baleen whales. The high likelihood of unreported fatal strikes combined with other anthropogenic threats suggests an urgent need for a comprehensive, basin-wide conservation strategy, including ship strike mitigation requirements, like real-time monitoring of whale presence and distribution to re-locate ferry routes to areas of lower cetacean density, and reducing ship speed in high cetacean density areas.     

地下水气体组分的潮汐变化

我们观察了日本中部Omaezaki地区地下水气体组分时间序列数据的周期性变化,Omaezaki是日本地震预报目录中即将到来的Tokai地震前兆信号观察的重要地区.我们已经开始在一口100 m深的井中对地下水中气体组分进行持续监测.     

Lethal toxicity of industrial detergent on bottom dwelling sentinels

We used fresh and brackish water shrimp （Desmoscaris trispinosa and Palaemonetes africanus）, in sediment bioassays to assess the toxicity of an industrial detergent containing high levels of anionic surfactant （linear alkylbenzene sulphonate （LAS））. The Organization for Economic Cooperation and Development （OECD）, # 218 direct sediment toxicity assessment was employed. The organisms were exposed to different concentrations （31.25, 62.5, 125,250 and 500 mg/kg） of the chemical （Neatex） in replicate treatments. Percentage mortality was measured as the ecological endpoint. Mean mortality and estimated lethal concentration LCso values varied with species type, concentration and exposure duration. The statistical variation in the observed mean mortality of the test organisms in the chemical and the control treatment shows that mortality may be induced by the effect of the chemicals. The lethal concentration （LCso） was significantly different at levels ofp 〈 0.05 for the fresh and brackish water experiments. Consequently, assessment of water and sediment quality as a result of chemical pollutants was necessary for protecting some of the more sensitive benthic invertebrates representing the major proportion of the diet of many species in the Niger Delta ecological zone.     

Engineering vibration monitoring by GPS： long duration records

Monitoring the performance of any structure requires real-time measurements of the change of position of critical points.Different techniques can be used for this purpose,each one offering advantages and disadvantages.The technique based on satellite positioning systems(GPS,GLONASS and the future GALILEO)seems to be very promising at least for long period structures.The GPS in particular provides sampling rates that are able to track dynamic displacements with high accuracy.Its service ability is indepen...     

形变单位在地震文献中的正确使用

针对地震观测技术论文中有关形变单位"毫秒",即10~(-3″)混用为时间单位ms的情况,笔者从单位符号的意义及观测技术仪器的工作原理出发,最终明确,地震观测仪器中倾斜仪观测量单位应为10~(-3″),不能以时间单位ms代替,二者不能混为一谈。     

Desertification of Mediterranean rocky reefs caused by date-mussel, Lithophaga lithophaga (Mollusca: Bivalvia), fishery: effects on adult and juvenile abundance of a temperate fish

Macroalgal beds in temperate rocky habitats provide shelter and food for many adult reef fishes and their juvenile stages. In the Mediterranean Sea, the fishery of the endolithic date-mussel Lithophaga lithophaga (which involves dismantling of rocky substrates inhabited by these bivalves) may cause formation of barrens in shallow rocky reefs. Preliminary data collected in SW Apulia (SE Italy) show that rocky reefs impacted by this destructive fishery display different distribution patterns of adult Coris julis (a common labrid fish in the Mediterranean basin), and lower abundance of juveniles. The ecological implications of date-mussel fishery for dynamics of fish populations and rocky-reef ecosystem functioning (e.g., nursery role) are discussed.     

Scale effect and calibration of contaminant transport models

The influence on solute transport of the small-scale spatial variation of aquifer hydraulic conductivity (K) was analyzed by comparing results from fine-grid (2 m by 2 m) simulations of a synthetic heterogeneous aquifer to those from coarse-grid (8 m by 4 m) simulations of an equivalent homogeneous aquifer. Realizations of the K field of the heterogeneous aquifer were generated, using the Monte Carlo approach, from a lognormal distribution with mean log K of 2 (K in m/d) and three levels of log K variance of 0.1, 0.5, and 1.0. Numerical simulation results show that the average standard deviation of point concentrations increased from 1.21 to 5.78 when the value of log K variance was increased from 0.1 to 1.0. The average discrepancy between modeled concentrations (obtained from a coarse-grid deterministic numerical simulation) and the actual mean point concentrations (obtained from fine-grid Monte Carlo numerical simulations) increased from 0.91 to 4.23 with the increase in log K variance. The results from this study illustrate the uncertainty in predictions from contaminant transport models due to their inability to simulate the effects of heterogeneities at scales smaller than the model grid.     

Benthic recovery after fish farming cessation: a "beyond-BACI" approach

The development of a benthic environment after fish-farming cessation was examined. To ascertain whether recovery occurred, several abiotic (granulometry, acid-volatile sulfides, total phosphorus and redox potential) and biotic (polychaete abundance) variables were monitored using a "beyond-BACI" approach. Before the cessation of farming, the geochemical conditions and polychaete assemblages differed among the impacted and control sites. After cessation, an improvement of the geochemical conditions was achieved. A significant tendency toward a recovery of the polychaete assemblage in the impacted area was observed, but significant differences still remained compared with the control sites. The acid-volatile sulfide level was responsible for these differences. The abundance of polychaete families associated with organically enriched sediments diminished at the impacted site after cessation, whereas the abundance of some sensitive and omnivorous families increased. The "beyond-BACI" approach provided a wider framework than other approaches, enabling us to differentiate the natural variability from those changes induced by the fish farm and farming cessation.