Mason C F, Macdonald S M
Department of Biology, University of Essex, Colchester, United Kingdom.
Sci Total Environ. 1993 Sep 30;138(1-3):147-60. doi: 10.1016/0048-9697(93)90411-x.
A study of otter (Lutra lutra) populations and levels of organochlorine (OC) pesticide residues and PCBs in otter faeces (spraints) was made on rivers in East Anglia, England. Population and contaminant levels are compared against target values. It is thought that the native otter population was almost extirpated during the study period. The current population must derive largely, if not entirely, from captive-bred animals introduced since 1983. Its range has expanded little and population levels, measured as an index, were generally low. Concentrations of OC pesticides and PCBs were similar to those of lowland stretches of western rivers; however, samples had a smaller proportion of dieldrin and a greater proportion of PCBs. Overall 44% of samples had concentrations of contaminants exceeding the 'level of concern'. It is considered that contamination, especially by PCBs, remains a factor influencing otter populations, which may not be viable in East Anglia without repeated releases of captive-bred animals.
对英格兰东安格利亚地区河流中的水獭（欧亚水獭）种群以及水獭粪便（粪迹）中的有机氯（OC）农药残留和多氯联苯水平进行了一项研究。将种群和污染物水平与目标值进行了比较。据认为，在研究期间，当地水獭种群几乎灭绝。目前的种群如果不是完全的话，很大程度上必须源自1983年以来引入的圈养繁殖动物。其分布范围几乎没有扩大，作为一个指标衡量的种群数量总体较低。OC农药和多氯联苯的浓度与西部河流低地河段的浓度相似；然而，样本中狄氏剂的比例较小，多氯联苯的比例较大。总体而言，44%的样本污染物浓度超过了“关注水平”。据认为，污染，尤其是多氯联苯造成的污染，仍然是影响水獭种群的一个因素，如果不反复释放圈养繁殖的动物，东安格利亚的水獭种群可能无法存活。
