The shy and elusive otter is still a rare sight in England and Wales. Otters' reproductive organs may be affected by chemicals in British waterways, according to scientists. Experts suggest that, based on previous research, the changes could be linked to hormone-disrupting chemicals. Photo: Nick Garbutt / Naturepl.com

By Michelle Warwicker
24 February 2013 (BBC Nature) – Otters’ reproductive organs may be affected by chemicals in our waterways, according to scientists. Experts studying the reproductive health of the mammals in England and Wales were concerned to find a decrease in the weight of otters’ penis bones. Other health problems in males included an increase in undescended testicles and cysts on sperm-carrying tubes. Experts suggest that, based on previous research, the changes could be linked to hormone-disrupting chemicals. The study, funded by the Environment Agency, was co-authored by the Chemicals, Health and Environment (CHEM) Trust and the Cardiff University Otter Project, and features on BBC One series Countryfile. “We were surprised to see the reduction in the baculum weight,” said co-author Dr Elizabeth Chadwick, project manager at the Cardiff University Otter Project, referring to the bone found in males’ penises. “[It’s] certainly something that needs further investigation.” During the 1970s, England’s otter population plummeted, the decline attributed to high levels of Persistent Organic Pollutants (POPs) in rivers. However contaminants such as organochlorine pesticides have mostly since been banned, and otter populations have steadily increased. Scientists examined hundreds of dead otters in a post-mortem laboratory to test if existing traces of POPs in rivers were still having an effect on the animals’ health. But they found no association between these old chemicals and the animals’ penis bones becoming lighter over time. Instead the report speculates that some modern contaminants could be causing the abnormalities. Previous studies have linked Endocrine Disrupting Chemicals (EDCs) to changes in animals’ reproductive organs, such as male penis size. “It’s from that that we’re drawing a possible inference that some of these Endocrine Disrupting Chemicals may be the reason that baculum weight has changed,” Dr Chadwick explained. EDCs are a range of synthetic and natural chemicals that can affect animals’ hormone systems, according to the World Health Organisation (WHO). [more]

Chemicals linked to problems with otters’ penis bones