Postmortem examinations were carried out on 341 otters retrieved between 1992 and 2000.
A detailed analysis of the health status and chemical burden of the otter in England and Wales, establishing a comprehensive baseline. Road traffic accounted for the majority of the otters submitted. Other causes of death included bite wounds and starvation. The population was considered to be in good health, road kill being a sampling method which tends to sample relatively healthy individuals. Non-lethal disease included the presence of renal calculi (kidney stones), which occurred in 10% of otters. Liver samples were removed and analysed for a range of organochlorine pesticides, PCBs and heavy metals. Mean levels were considered to be generally low, although large ranges were observed. There was a strong intercorrelation between toxicants, particularly individual PCB congeners, but also between total PCB and the OC pesticides. The level of toxicant observed in an individual otter may be affected by its geographical origin, health and reproductive status.