Cabrita Maria Teresa
Portuguese Institute of Sea and Atmosphere (IPMA), Av. de Brasília, 1449-006 Lisboa, Portugal.
Environ Pollut. 2014 Aug;191:17-24. doi: 10.1016/j.envpol.2014.04.001. Epub 2014 May 5.
This work reports changes in suspended particulate matter, turbidity, dissolved Cr, Ni, Cu, Cd, Hg and Pb concentrations, and phytoplankton biomass and composition during a 5-month period dredging operation, in a trace element contaminated area of the Tagus estuary (Portugal). Phytoplankton biomass, diatom:other groups ratio, benthic:pelagic diatom ratio, Margalef's, Simpson's diversity, Shannon-Wiever's, and Warwick and Clarke's taxonomic diversity and distinctness indices, and individual taxa were investigated as indicators of dredging induced changes. Significant rise in sediment resuspension and trace element mobilisation caused by dredging influenced the community structure but not the overall biomass. Benthic diatom displacement into the water column maintained species diversity, and therefore, none of the indices highlighted community changes. Contrastingly, diatom:other groups ratio and benthic:pelagic diatom ratio were reliable indicators for the assessment of dredging induced changes. A shift in composition towards species less susceptible to trace elements was observed, disclosing some individual taxa as potential indicators.
这项研究报告了在塔霍河河口（葡萄牙）一个受微量元素污染的区域进行为期5个月的疏浚作业期间，悬浮颗粒物、浊度、溶解态铬、镍、铜、镉、汞和铅的浓度，以及浮游植物生物量和组成的变化情况。研究了浮游植物生物量、硅藻与其他类群的比例、底栖硅藻与浮游硅藻的比例、马加利夫指数、辛普森多样性指数、香农-韦弗指数、沃里克和克拉克分类多样性及独特性指数，以及各个分类单元，将其作为疏浚引起变化的指标。疏浚导致的沉积物再悬浮和微量元素活化显著增加，影响了群落结构，但未影响总体生物量。底栖硅藻向水柱中的迁移维持了物种多样性，因此，没有一个指数突出显示群落变化。相比之下，硅藻与其他类群的比例以及底栖硅藻与浮游硅藻的比例是评估疏浚引起变化的可靠指标。观察到组成向对微量元素不太敏感的物种转变，揭示了一些个别分类单元可作为潜在指标。
