Otters as sentinels for environmental health

On Wednesday 23 November 2016, Dr Elizabeth Chadwick talked to the Society about the work of the Cardiff University Otter Project, which she has managed for twelve years. The talk emphasised the otter’s importance as an indicator species for the general health of river ecosystems, and as a charismatic umbrella species that provides a focus for education and freshwater habitat conservation.

The Eurasian otter (Lutra lutra), one of 13 otter species worldwide, has an extensive range extending across continental Europe, Russia, China, and parts of north Africa; though in modern times its populations have become fragmented. In the UK, populations dramatically declined between the 1950 and 1970s, with chemicals in the environment (e.g. PCBs and organochlorine pesticides) mainly to blame. However, this protected species has recovered in the UK, and its once-isolated UK populations are again interacting. Nevertheless, by nature it is non-sociable and lives at low densities, so it can be hard to spot in the countryside.

Dr Chadwick explained the different methods used to monitor otters. The main methods used by the Cardiff University Otter Project are the monitoring of spraint (faeces and scent gland secretions) and the post-mortem of dead otters (mainly roadkill reported by the public).

A study of the spraint otters deposit at prominent locations around their territories is revealing interesting information. The spraint contains 432 volatile chemicals, and its smell is unique to an individual. The components of the spraint marking also change with age, enabling adults and juveniles to be identified.

The Cardiff University Otter Project started collecting samples from dead otters in the 1990s, when it would process around 10 otters/year (this figure is now around 200/year due to the otter’s recovery). This large sample bank now amounts to 3,000 specimens that can be used retrospectively for a wide range of interdisciplinary studies. Dr Chadwick described some of the studies that Cardiff University and its collaborators have done with these samples. These include studies on the presence of chemical contaminants over time and the effectiveness of legislation (e.g. bans on pesticides and lead), parasites infecting otters, dietary studies from stomach contents (83% fish), and genetic studies over time as a more contiguous UK population re-established. New areas of study include looking for the presence of micro-plastics and a new wave of emerging pollutants (e.g. pharmaceuticals).

For further information, visit the project’s website: www.otterproject.cf.ac.uk

Report by Stephen Nottingham

Parasites of The Eurasian Otter

Ellie Sherrard-Smith gave us a fascinating insight into the parasites that effect Otters and what they can tell us about their lives and distribution patterns, Not one for the squeamish tonight with some views if lice being a bit closer than I like to be where they are concerned, but fascinating all the same

This was another presentation from the excellent work that is being done by the Cardiff Otter project team and

Otters in Cardiff

We were pleased to receive this email from one of our members (Pauline Peregrine) recently who took a walk in Easrern Cardiff

"I don't know if you keep records of sightings - but would like to tell you that we saw an otter in the River Rhymney yesterday!  Clearly, I don't want to be too specific on the location for obvious reasons!  We were delighted to see the Otter - closest sighting we've ever had!"

The simple answer is yes we do like to keep records especially of unusual sightings and we would love to tell you about more of them here so we encourage people to let us know and also possibly record them directly with SEWBrec via their recording form at http://sewbrec.org.uk/recording-form.page

We know that the SEWBrec team keep in touch with information from the society so if you prefer to just tell us that's not problem

In the event of finding a dead otter, please telephone 08708 506506 (Environment Agency) and ask for your nearest conservation / biodiversity officer. You will be asked for the location of the otter and some other basic information.

The Cardiff Otter project investigate dead otters to determine cause of death and how that relates to their lifestyles. You can read more about such at the Cardiff Otter project website http://www.otterproject.cf.ac.uk/

Regards

Andy