Lichen transplants as a suitable tool to identify mercury pollution from waste incinerators: a case study from NE Italy

A lichen transplant study aimed at investigating a strong increase in mercury concentrations in lichens was run in a territory of NE Italy where background values were very low only 8 years before. Thalli of the lichen Pseudevernia furfuracea collected in a pristine area were exposed for 1.5, 3 and 6 months at 31 sites selected according to the observed pattern of Hg concentrations, location of the suspected source (a new waste incinerator) and prevailing wind direction. Hg strongly increased at eight sites after 1.5 months, at 12 after 3 months and at 20 after 6 months. The highest values were always located SW and S of the incinerator, in good agreement with the prevailing night wind direction. It was concluded that, although the immediate risk for the population living close to the incinerator is low, long-term hazard due to Hg accumulation in the surrounding environment should be seriously taken into account.     

Sediment organic matter and meiofauna community response to long-term fish-farm impact in the Ligurian Sea (Western Mediterranean)

Quantitative and qualitative changes in meiofauna community structure were investigated to assess the impact of a fish farm, which was operating continuously for 15 years (La Spezia Gulf, W Mediterranean). Sediment samples were collected in June, July, September, October 2000 and February 2001 for the analysis of phytopigments (chlorophyll-a and phaeopigments), the biochemical composition of organic matter (proteins, carbohydrates and lipids) and related to meiofaunal parameters.

Sediment organic matter reached extremely high concentrations beneath the fish cages when compared to the control. Particularly lipids, carbohydrates and chlorophyll-a were significantly higher in fish-farm sediments. On a long-term basis meiofauna displayed adaptations in sediments beneath the cages resulting in an increase of density. Organic impact on meiofaunal community structure was evident in terms of an increase of the nematodes to copepods (Ne/Co) and nauplius to copepods (Na/Co) ratios in fish farm sediments. Cumaceans and kinorhynchs were encountered in control sediments, but disappeared in fish-farm samples. These data suggest that meiofauna is a sensitive tool for evaluating the effects of organic enrichment in fish farm impacted areas.     

Mutagenic activity of transition‐metal complexes: Relation structure‐mutagenic and antibacterial activity for some Pd(II), Pt(II) and Rh(I) complexes†

The inhibitory and mutagenic action of some Pd(II), Pt(II) and Rh(I) complexes towards various bacterial strains has been evaluated, and some correlations have been found between the chemical behaviour of the complexes and their selective biological activity: most of the complexes cause only a DNA damage repaired by the excision repair system. Particularly, the Rh(I) complexes used in this work show selective antibacterial effects on defective but no effect on wild‐type strains.     

On estimating Hooded crow density from line transect data through exponential mixture models

Line transect sampling is a distance sampling method widely used for estimating wildlife population density. Since the usual approach assumes a model for the detection function, the estimate depends on the shape of such a function. In particular, the estimate is influenced by the so-called shoulder condition, which ensures that detection is nearly certain at small distances from the line transect. For instance, the half-normal model satisfies this condition, whereas the negative exponential model does not. The aim of this paper is to propose the exponential mixture model of the half-normal and the negative exponential in order to estimate the population density in the case where the shoulder condition is not guaranteed. Such a case study on Hooded crow is described in the paper.     

Energy and resource basis of an Italian coastal resort region integrated using emergy synthesis

Sustainable development of coastal zones must balance economic development that encourages human visitation from a larger population with desires that differ from the local residents with the need to maintain opportunities for the local resident society and conserve ecological capital, which may serve as the basis for residents.We present a case study in which the sustainability level of a coastal zone (Riviera del Beigua), located along the Ligurian coast of north-western Italy, was assessed through the lens of systems ecology using emergy synthesis to integrate across economic, social and environmental sub-systems.Our purposes were (1) to quantify the environmental sustainability level of this coastal zone, (2) to evaluate the role of tourism in affecting the economy, society and environment, and (3) to compare emergy synthesis to Butler's Tourism Area Life Cycle model (TALC). Results showed that 81% of the total emergy consumption in the coastal zone was derived from external sources, indicating that this tourist-heavy community was not sustainable. Tourism, as the dominant economic sub-system, consumed 42% of the total emergy budget, while local residents used the remaining 58%. The progressive stages of the TALC model were found to parallel the dynamic changes in the ratio of external emergy inputs to local emergy inputs, suggesting that emergy synthesis could be a useful tool for detecting a tourist region's TALC stage. Use of such a quantitative tool could expedite sustainability assessment to allow administrative managers to understand the complex relationship between a region's economy, environment and resident society so sound policies can be developed to improve overall sustainability.     

鼋头渚不同年龄夜鹭卵中多氯联苯污染状况及分布特征

通过对太湖鼋头渚2000年采集的2龄、3龄和4龄夜鹭所产卵中15种多氯联苯同系物残留状况的研究,发现所有样品中均检出多氯联苯,残留量最高的为PCB₁₁₈,PCB₈₇,PCB₁₀₁和PCB₁₅₃,占PCBs残留量的75%～85%.含5～6个氯原子的同系物在夜鹭卵中的PCBs残留量明显高于其它类型的同系物.同时,多氯联苯残留量随亲鸟年龄增加而明显增加.4龄卵样分别比3龄、2龄卵样中PCBs残留量高出47.5%和60.9%.统计处理结果表明:多氯联苯残留总量与亲鸟年龄呈正相关(p=0.05).PCBs总量与亲鸟年龄呈正相关(p=0.05).与欧美日等国家同类研究结果中PCB₁₅₃残留量最高的情况略有不同,本研究在夜鹭卵中发现残留量最高的是PCB₁₁₈,占PCBs残留总量的30%左右,PCB₁₅₃含量仅为PCBs残留总量的17%左右.     

不同年龄夜鹭卵中有机氯农药污染的生物指示

通过对太湖鼋头渚 2 0 0 0年采集的二龄、三龄和四龄夜鹭卵以及相应年龄组夜鹭的捕食物中有机氯残留的检测 ,发现捕食物中HCH和DDT的平均残留量随年龄增加而增加 .除γ HCH外 ,其它 15种有机氯农药在卵样中均有检出 ,残留水平最高的为p ,p′ DDE ,占有机氯农药残留总量的 85 %以上 .β HCH是六六六类中持留性最强的组分 ,其残留量仅次于p ,p′ DDE .研究发现 ,p ,p DDT和 β HCH检出率为 10 0 % ,而其它类型农药只有很低的检出率 ,这与我国有机氯农药使用的历史情况相吻合 .随着亲鸟年龄增加 ,卵中 β HCH残留量有所提高 ,p ,p′ DDE残留量似有先升后稍降的趋势 .统计结果表明 :各年龄组有机氯残留量差异不明显 ,因此在用夜鹭卵作有机氯污染的生物指示时可以不考虑年龄差异所带来的影响 .     

A discrete model for estimating the development time from egg to infecting larva of Ostertagia ostertagi parametrized using a fuzzy rule-based system

Ostertagia ostertagi is a nematode, predominantly affecting cattle in the Pampean region of Argentina. A mathematical model parametrized using fuzzy rule-based systems of the Takagi-Sugeno-Kant type (FTSK) for estimating the development time from egg to infecting larval stage L3 of the gastrointestinal parasite O. ostertagi is here proposed. The estimation of development time of O. ostertagi is essential for the generation of appropriate control mechanisms, since this provides information about the time when parasites are ready to migrate to pastures. For the purpose of reflecting the natural environmental conditions, the mean daily temperature is taken as the main and only regulator of the development time. Humidity conditions are considered to be sufficient for the normal development of the larvae. Hence the individual's daily growth is a function of its length and the mean temperature recorded on the previous day. It is expressed in terms of a difference equation with fuzzy parameters, which are defined using laboratory data. Model outputs are tested against results of field experiments. Simulation results are very satisfactory, yielding a mean estimation error (MEE) of 0.64 weeks, with variance 0.34, and a determination coefficient R² = 0.74. The model clearly exhibits an inverse relationship between development time and temperature both in controlled and in field conditions. It also exhibits a very sensitive response both to the order in which the temperature sequence occurs, - reproducing the differences observed between spring and autumn - and to the amplitude of the temperature range.