Biomonitoring of wild fish to assess chemical pollution in English rivers:an application of a fish tissue archive

摘要

Since 2007 CEH and the Environment Agency are building a Fish Tissue Archive by annually collecting roach (and in 2007/08 also some eels and bleak) from a number of English river sites and storing them long-term at -80°C. This provides a resource for retrospective monitoring of bioaccumulative pollutants in the fish tissue - allowing future scientists to answer questions that cannot yet be answered or are not yet asked. By the end of 2014, 1684 fish had been collected of which 179 have so far been analysed for one or more groups of chemicals: metals, organochlorine pesticides, PCBs and PBDEs. The results from the individual fish were compared to each other as well as to regulatory standards and previously published UK and European data. Some of the results are: With the exception of lead in 3% of analysed individuals, no food standards were exceeded, but the environmental quality standard (EQS) for mercury was exceeded in the majority of samples (111/144) and the very low EQS for PBDEs was greatly exceeded in all samples. Some patterns found were:  Mercury and selenium increased with size of the fish and to some extent with the distance of the sampling site from the river source.  PBDE concentration correlated well with the modelled concentration of treated sewage at the sampling site  A hotspot was found for DDTs (banned in 1981) and to a lesser extent lindane, chlordane and copper. Further investigations revealed that a pesticide factory had been located close to the sampling site for much of the 20th century. This shows how unexpected results can point to previously unknown issues, which warrant further investigation.  Compared to previous European data, eels were generally less contaminated with organic pollutants and roach were low in mercury and cadmium, but relatively high in lead.