Are chemicals damaging the health of male otters?

A new report has highlighted serious concerns for the health of otters in the UK. The otter is one of the country's best loved predator species, but research indicates that they may not be in the best of reproductive health.

The report, co-authored by the Cardiff University Otter Project and CHEM Trust (Chemicals, Health and Environment Monitoring Trust), raises the question as to whether modern chemicals - particularly endocrine disrupting chemicals (EDCs) - could be to blame.

The current report shows that despite an increase in the otter population, male otters in particular are showing worrying signs of change in their reproductive organs. The report - entitled Persistent organic pollutants and indicators of otter health: other factors at play? -was written by two of the UK's leading researchers on otters: Dr Elizabeth Chadwick and Dr Eleanor Kean of the Cardiff University Otter Project.

The researchers looked at several indicators of male reproductive health and found several signs of change that give cause for concern: shrinking reproductive organs; an increase in cysts on the tubes that carry sperm during reproduction, and an increase in undescended testicles (cryptorchidism).

It is not possible to determine exactly what the causes of these changes are, but various studies, both in the laboratory and in wildlife, have suggested links between hormone disrupting chemicals and problems with male reproductive health.

Dr Kean of Cardiff University's School of Biosciences stated: "The otter is an excellent indicator of the health of the UK environment, particularly aquatic systems. Our contaminant analyses focused on POPs that were banned in the 1970s, but which are still appearing in otter tissues now – other chemicals, in current usage, are not yet being monitored in wildlife. There is a clear need to regularly revise the suite of contaminants measured – failure to do so may lead to a false sense of security and cause emerging threats to otters and UK wildlife to be missed."

Gwynne Lyons, Director of CHEM Trust, added: "If we are to protect our wildlife, we need good information on the reproductive health of key species in both the terrestrial and aquatic environments. These findings highlight that it is time to end the complacency about the effects of pollutants on male reproductive health, particularly as some of the effects reported in otters may be caused by the same EDCs that are suspected to contribute to the declining trends in men's reproductive health and cause testicular cancer, undescended testes and low sperm count."

CHEM Trust is calling for the UK Government and the EU to urgently identify hormone disruptors to ensure that chemicals suspected of playing a role in male reproductive health problems are substituted with safer alternatives.