Microalgae worldwide regularly cause harmful effects, considered from the human perspective, in that they cause health problems and economic damage to fisheries and tourism. Cyanobacteria cause similar problems in freshwaters. These episodes encompass a broad range of phenomena collectively referred to as “harmful algal blooms” (HABs). For adequate management of these phenomena, monitoring of microalgae is required. However, effective monitoring is time-consuming because cell morphology as determined by light microscopy may be insufficient to give definitive species and toxin attribution. In the European Union FP7 project MIDTAL (Microarrays for the Detection of Toxic Algae), we achieved rapid species identification using rRNA genes as the target. These regions can be targeted for probe design to recognise species or even strains. We also included antibody reactions to specific toxins produced by these microalgae because, even when cell numbers are low, toxins can be present and can accumulate in the shellfish. Microarrays are the state-of-the-art technology in molecular biology for the processing of bulk samples for detection of target RNA/DNA sequences. After 36 months, we have completed RNA-cell number–signal intensity calibration curves for 18 HAB species and the analysis of monthly field samples from five locations from year 1. Results from one location, Arcachon Bay (France), are reported here and compared favourably with cell counts in most cases. In general, the microarray was more sensitive than the cell counts, and this is likely a reflection in the difference in water volume analysed with the volume filtered for the microarray an order of magnitude greater. 相似文献
From December 1994 up to October 1995 a “Mussel Watch Project”; was carried out to assess the quality of water of the Ligurian Sea and to identify the possible sources of heavy metal pollution. Several metals and organotin compounds were measured in mussels (Mytilus galloprovincialis, Lam) transplanted in different months from a marine farm to eight sites of the Ligurian coast. Spatial differences and temporal trends in tissue concentrations of Zn, Cu, Ni, Cr, Fe, Al, V, Cd and Mn were evaluated. Concentrations resulted in the same range as those obtained in a previous Mussel Watch Project carried out in the same area. In general, areas of known pollution display high concentrations of these metals, but also some areas not greatly influenced by human activities showed high concentrations of some metals. Data from this study show little evidence of any overall seasonal pattern except for Cu, Zn and V, concentrations of which were a function not only of sampling site, but also of reproductive cycle. Organotin compounds show differences in terms of both concentration and speciation between the investigated sites. 相似文献
Aljustrel mining area (South Portugal) is a part of the Iberian Pyrite Belt and encloses six sulfide mineral masses. This mine is classified of high environmental risk due to the large tailings’ volume and acid mine drainage (AMD)-affected waters generated by sulfides’ oxidation. The use of biological indicators (e.g., diatoms) revealed to be an important tool to address the degree of AMD contamination in waters. Multivariate analysis has been used as a relevant approach for the characterization of AMD processes. Cluster analysis was used to integrate the significant amount and diversity of variables (physicochemical and biological), discriminating the different types of waters, characterized by the high complexity occurring in this region. The distinction of two main marked phenomena was achieved: (1) the circumneutral-Na-Cl water type (sites DA, PF, BX, BF, RO, CB), expressing the geological contributions of the Cenozoic sediments of Sado river basin, with high diatom diversity (predominating brackish diatoms as Entomoneis alata); and (2) the acid–metal-sulfated water type (sites BM, JU, RJ, AA, MR, BE, PC, AF), reflecting both the AMD contamination and the dissolution of minerals (e.g., silicates) from the hosting rocks, potentiated by the extremely low pH. This last group of sites showed lower diatom diversity but with typical diatoms from acid- and metal-contaminated waters (e.g., Pinnularia aljustrelica). In addition to these two water types, this hierarchical classification method also allowed to distinguish individual cases in subclusters, for example, treated dams (DC, DD), with alkaline substances (lime/limestone), that changed the physicochemical dynamics of the contaminated waters.
This paper reports the results of a study using lichens as biomonitors to investigate the environmental distribution of uranium and other trace elements at selected Kosovo sites. The results suggested that the use of depleted uranium (DU) ammunitions in Kosovo did not cause a diffuse environmental contamination in such a way to have caused a detectable U enrichment in lichens. Also isotopic (235)U/(238)U measurements did not indicate the presence of DU particles in lichens. The present results also provided no indication of intense environmental contamination by the other trace elements analyzed, with the exception of Kosovska Mitrovica, where a diffuse environmental contamination by several heavy elements such as Pb, Zn, As and Cd was found. 相似文献
This study investigates the effects of several blends of gasoline and anhydrous ethanol on exhaust emission concentrations of carbon monoxide (CO), total hydrocarbons (HCs), and nitrogen oxides (NOx) from a small spark-ignited non-road engine (SSINRE). Tests were carried out for different air/fuel equivalence ratios as measured by lambda (λ). A 196 cm3 single-cylinder four-stroke engine-generator operating at a constant load of 2.0 kW was used; pollutant gas concentrations were measured with an automatic analyzer similar to those typically used in vehicle inspections. The results showed that as the ethanol content of the mixture increased the concentrations of CO, HCs, and NOx reduced by 15, 53, and 34%, respectively, for values of λ < 1 (rich mixture) and by 52, 31, and 16% for values of λ > 1 (lean mixture). Overall, addition of anhydrous ethanol to the gasoline helped to reduce emissions of the pollutant gases investigated, what contributes to photochemical smog reduction and quality of life in urban areas. 相似文献
In Argentina no historical or present programs exist specifically assessing ecosystem health with respect to photochemical
air pollution, although phytotoxic concentrations of near-ground ozone have been documented in recent years. Here we report
our preliminary findings on field observations of ozone-like injury found in natural plant populations and agroecosystems
late in the 2005 growing season in the Southern Hemisphere. Several possible ozone bioinidicator plants which have not been
previously documented were observed to exhibit foliar symptoms consistent with ozone-induced injury. Based on these results
we intend to expand field surveys and complete the screening process for injury confirmation of the plant species described
here. For this and future research we will be using controlled chamber studies based in the US. Continuous monitoring of tropospheric
ozone does not currently take place in the region of central Argentina. The combined evidence provided by intermittent air
quality sampling and the presence of ozone-like injury to vegetation indicates the need to establish air quality and ozone
biomonitoring networks in this region. 相似文献
Continuous methane, CH4, concentrations were measured in a rural area of the upper Spanish plateau from June 2010 to May 2012 by cavity ring-down spectroscopy technique. The results obtained have proven the local impact of anthropogenic nearby sources on CH4 concentrations, and evidence a significant influence on the overall mean, averaged daily and seasonal patterns recorded at the measuring site. The positive anomalies in CH4 concentrations, statistically significant at 95 %, in the southeast sector, defined here as ESE, SE, SSE and S sectors, have been attributed to the contribution of the Valladolid urban plume and the urban landfill. Based on this finding, CH4 background levels were associated to the concentrations recorded in the remaining un-disturbed sectors. CH4 means of the overall data set, the southeast sector and background sectors yielded average means of 1,894.1, 1,927.9 and 1,887.1 ppb, respectively. The diurnal and seasonal patterns of the overall data set and background concentrations have shown that CH4 concentrations are mainly dominated by its reaction with OH radicals. Maximum hourly concentrations were reached during night-time and early morning, 5–7 h, whereas minimum concentrations were recorded at 16 h. Maximum and minimum monthly means were recorded in January and July, respectively. The diurnal and seasonal amplitudes, namely, peak-to-peak means, of background concentrations were 25.1 and 48.1 ppb, respectively. These values were significantly lower than those obtained for the overall data set, 42.9 and 58.1 ppb, revealing the significant role of local influences on CH4 concentrations despite the low frequency of southeast winds recorded at the measuring site, 16.9 %. 相似文献
We re-sequenced 815 bp of the mtDNA of loggerhead turtles from a population nesting in Calabria (southern Italy), which was
found recently. Non-invasive sampling was applied and information on deposition date and place was used to avoid possible
resampling of nesting females. Among 38 nests laid by independent females, we found the common haplotype CC-A2.1 (57.9%) and
two other haplotypes which have never been described in Mediterranean nesting grounds, CC-A20.1 (36.8%) and CC-A31.1 (5.3%).
Calabria harbors the highest intra-population diversity among 11 Mediterranean nesting populations. Our findings narrow the
gap between haplotypes recorded in feeding grounds and those found in nesting grounds. Analyses of population structure show
a strong maternal isolation, with Calabria and east Turkey displaying far more diversity than expected considering their census
size. These observations suggest that recurrent female founder effects from sources yet to be identified in the Atlantic or
in the Mediterranean may have shaped the pattern of mtDNA diversity in this latter basin. Our results provide evidence that
the Ionian Calabrian sites should be protected because of the high diversity found there.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
Mercury is a high-priority regulatory concern because of its persistence and bioaccumulation in the environment and evidence
of its having serious adverse effects on the neurological development of children. 相似文献