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Title: Health and ecotoxicology of otters: summary of four studies from 1988-2003
Author: V.R. Simpson
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1194, Representation ID: 375, Object ID: 2414
A total of 1027 otters were examined in the study period. Most of these were adults, of which 62 per cent were male and 38 per cent female. Among the juvenile animals submitted, the sex ratio was 1:1. The number of otters submitted has increased year on year. Currently, approximately 140 otters are examined each year. Most are found in winter, the number of otters killed on roads is strongly correlated to the hours of darkness, with the highest numbers submitted between October and March. There is a peak in the number of otters killed in February. The majority of otters died as the result of road traffic accidents; over 83% in southern England, and 92% in the rest of England and Wales. In southern England a further 11% died as the result of bite wounds and subsequent infection. Other causes of death included young cubs that had been abandoned and either starved or were killed by dogs; and a small number of otters killed illegally by snares or drowned in fyke nets. Wild otters are generally healthy. However, these studies give a remarkable insight into some aspects of their health and lifestyle. The distribution of pollutants in otters was analysed by region. The highest levels of organochlorine pesticides occurred in the Midlands. Other rankings varied between different chemicals, however PCBs and HCB were highest in the North East and North West regions. Overall, pollutant concentrations are higher in adult males than in adult females. This almost certainly results from the excretion of these compounds during pregnancy and lactation. Juvenile otters had high levels of pollutants, presumably as a consequence of the same mechanism. Evidence suggests that OCs and PCBs accumulate with age in males, while in females an initial increase was followed by a decline in concentration following sexual maturity.
Publisher: Environment Agency
Subject Keywords: RiversAquatic mammalsPesticidesPathologyPollutantsOrganochlorine compoundsMortality
Geographic Keywords: EnglandWales
Taxonomic Keywords: Lutra lutra
Extent: 16
Total file downloads: 44

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