Inshore/offshore gradients of imposex and organotin contamination in Nassarius reticulatus (L.) along the Portuguese coast

Imposex and organotin (OT) tissue contamination of the netted whelk Nassarius reticulatus (L.) were assessed in the continental shelves around the main estuaries of the central coast of Portugal (Lisbon: Tagus estuary; Setúbal: Sado estuary) and the main coastal lagoon in the Southern of Portugal (Faro: Ria Formosa). Pollution levels were higher in areas of more intense boat traffic and shipyard activities and imposex showed a clear decreasing gradient from the estuaries to the offshore, in relation to a similar gradient of tissue contamination by tributyltin. Remarkably, imposex was extensively spread over the adjacent continental shelves of Tagus and Sado estuaries. The current work shows that TBT pollution is undoubtedly a matter of concern not only for the above estuaries where harbours are implanted but also for the adjacent continental shelves, regardless the massive dilution of contaminants that may occur in these deeper areas.     

Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide

In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected Areas but must include areas outside such reserves. This contribution reviews the current situation of integrative ecological assessment worldwide, by presenting several examples from each of the continents: Africa, Asia, Australia, Europe and North America.     

Multixenobiotic resistance, acetyl-choline esterase activity and total oxyradical scavenging capacity of the Arctic spider crab, Hyasaraneus, following exposure to bisphenol A, tetra bromo diphenyl ether and diallyl phthalate

The Arctic has become a sink for persistent organic pollutants (POPs) originating from lower latitudes, and relatively high levels have been found in different biota. Recent studies have identified detrimental effects on wildlife including endocrine disruption, impairment of enzyme activity, and reduced immune function. The Arctic spider crab, Hyas araneus, shown interesting potential for its use as sentinel organism in polar ecosystems. This study investigated the effect of 2,2',4,4'-tetra bromo diphenyl ether (BPDE), bisphenol A (BPA), and diallyl phthalte (DPA) on H. araneus in a three weeks exposure study. Expression of multixenibiotic resistance (MXR) proteins has been studied using the C219 monoclonal antibody which allows identifying an immunoreactive protein of 40 kDa in the digestive gland while no such protein could be observed in the gills. Expression of this protein was increased by exposure to DPA (+75%; p<0.05, n=10). All compounds significantly affected muscle acetylcholine esterase (AChE) activity (p<0.05, n=10) with 50 microg/L DPA having the strongest effect by lowering the value to 37% of control. The total oxyradical scavenging capacity measured in the digestive gland toward peroxyl, hydroxyl and peroxynitrite was also significantly reduced indicating a decreased resistance to oxidative stress generated by DPA (p<0.05, n=5). These results thus suggest the potential detrimental effects of DPA even at concentration as low as 50 microg/L on H. araneus.     

Trace metal concentrations in Antarctic sea spiders (Pycnogonida, Pantopoda)

Trace metals were analysed in sea spiders collected on two Polarstern cruises in the Weddell Sea. We found a substantial interspecific heterogeneity of Cd, Cu, Ni, and Zn, indicating varying accumulation strategies and metabolic demands for essential elements. Means and 95%-confidence intervals for all 44 samples analysed are 26+/-7 mg Cd kg(-1), 38+/-22 mg Cu kg(-1), 62+/-13 mg Ni kg(-1) and 990+/-130 mg Zn kg(-1) DW. Only for Pb do we find values less than 1.0 mg kg(-1) for most collectives analysed, in good agreement with other Antarctic arthropods such as crustaceans. Our study provides further evidence for the frequently reported "Cd anomaly" in many polar arthropods. While Cu concentrations in pantopods are within the reported range for Antarctic amphipods and decapods, Ni concentrations are exceptionally high and might be part of predation defence mechanisms. These possibilities should be investigated in more detail in future studies.     

海平面变化研究进展

海平面变化研究进展Ｂ．Ｕ．Ｈａｑ海平面变化与大气、大洋和岩石圈体系的长期变化密切相关。这些体系的长期不稳定性可以引起大的海平面波动，这种波动的持续期较长，由数千年至数百万年。例如，自末次冰期极盛时结束以来，海平面升高约１１０ｍ。然而，大约４ｋａ前，全...     

由地震目录自动重构断层网络:三维最优各向异性动态群聚

利用地震的空间位置分布,提出了一种可以重构断层网络活动部分的三维结构的模式识别新方法。该方法为所谓动态群聚(或称k均值)方法的推广,是利用震源位置关于它们的中心的全局方差最小化准则将数据点集划分为群集。这种新方法比原来的k均值方法更好,因为它为了把数据集划分为断层形状的各向异性群集而考虑了每个群集全空间位置的协方差张量。给定地震事件目录,就可以输出符合数据空间结构的最优集的平面段。每个平面段在它的位置、大小和取向上都有明显区别。主要的可调参数为地震定位精度,它固定了分辨率,即拟合的剩余方差。分辨率决定了描述地震目录所需要的断层段数目:分辨率越高,重构断层段的结构越精细。该算法成功地重构了合成地震目录的断层段。把该方法用于1992年6月28日发生在南加州兰德斯地震余震序列子集的真实地震目录,重构的断层面段与地质图上已知的断层或者长期目录中明显出现的盲断层完全吻合。讨论了该方法将来的进一步改进及其在断层带内结构的多尺度研究的潜在应用。