The Wild Carp Otolith In Response To The Eutrophication Of The Water In The Xiaoxi Port Of The Taihu Lake, Eastern China

Water environmental degradation has become a great threat to human health including thehuman living environment and food safety. As China’s third largest freshwater lake.With theincreasing utilization of The Taihu Lake and a large number of domestic sewage (nitrogen,phosphorusand other pollutants) emissions, the organic pollution and lake eutrophication are gettingworse and worse. On the lake eutrophication. It is necessary to explore more economical, efficientand effective approach for dynamic monitoring and evaluation of water quality.As a sensitive recorder of the ambient water and fish exposures, fish otolith has been studied asa potential dynamic monitor of water quality by many biologists and mineralogists.In order to work out the correlation of phosphorus enrichment in carp otoliths to the ambient waterof47tail wild carps in the3-4age, the phosphorus concentration in carp otoliths was measured insitu using laser ablation plasma mass spectrometry (LA-ICP-MS) and comparison with the2005-2008relevant data from1.50m of the water was conducted in Xiaoxi Port of the Taihu.Research results show，Strong enrichment of phosphorus in lappillae from water was found inXiaoxi port of the Taihu Lake, and the phosphorus content in lappillae was2to4orders ofmagnitude higher than that in the water. It is much more convenient to measure phosphorus contentin lappillae than in water. Although there is a big difference in phosphorus content from individuallappillae samples, the trend of phosphorus content in the same time period was broadly consistentfor all samples; therefore it is possible to set a correlation model for phosphorus content in lappillaeand in water. An almost same trend of phosphorus content was found in lappillae and in water fromlatter half of2005to late2007in the Taihu Lake, showing relatively lower phosphorus content in2005and higher phosphorus content during2006to early2007, but lower content in late2007again.The result reveals that phosphorus accumulated gradually for about two years before the largebloom of blue-green algae in2007to provide nutrition for the algae growth; the phosphorus contentreached maximum during the large bloom of blue-green algae and then decreased because thephosphorus was absorbed by the large amount of algae. Significant positive correlation was foundfor phosphorus concentration in carp otoliths to the ambient water in the corresponding time.phosphorus content inlapilli can be used for determining the varying tendency of phosphoruscontent in ambient water and to predict the blue-green algae pollution in the future. Phosphoruscontent in lappillae might be used as potential recorder for organic or phosphorus pollution of water.Different heavy metal elements in the otolith deposition is selective, Cr, Ba, Fe, Mg etc elements onthe response of the environment is sensitive, However Cu, Pb, Mn, Zn etc elements in the otolithwhole growing process the content are not there is a major change, To the environment the responseis sensitive. Based on the research, Carp otolith can be used as its life water eutrophication statusand heavy metal pollution environment beacon type. It can be traced back carp life at differenttimes of the water eutrophication status and heavy metal pollution situation, For lakes watereutrophication elements and heavy metal element abundance of dynamic change and long timemonitoring provides a potential life mineralogy method.