SPRING 2003 No. 16

Page 7

Many of the reasons for the otter's decline, the blame for which can be laid firmly at our door, have now addressed. We have stopped poising our waterways with organochlorine pesticides and have ended the brutality of otter hunting (although it is sad to reflect that there is good evidence that otters are still being illegally killed), the quality of the water in our rivers has improved and so had the management or our river banks and fish stocks. However, as Alastair Driver, the Environment Agency's National Conservation Manager, has said: 'Despite the good news, we can't become complacent. Otters are not increasing as fast as we would like in some areas and we will need to concentrate on ways to protect the otter from the motor car – which continues to be one of the biggest threats to the otter'.

We should celebrate the otter's return but its journey has not yet ended. The work of the Dorset Otter Group will continue to have an important role in the years to come. If any new threat to the welfare of the otter arises in the future it will be people like ourselves who will probably be amongst the first to notice it.

Peter Irvine

'The loss of the otter from much of our countryside in the 60s and 70s was a tragedy. Its welcome return through the actions of many people shows that declines can be reversed. As the otter returns, we can expect to see all sorts of other freshwater plants and animals return to our rivers and wetlands.'

Tony Mitchell – Jones, English Nature

Otter deaths in southern England

When a dead otter is received by the Environment agency in the south of England it is sent to The Wildlife Veterinary Investigation Centre, run by Vic Simpson at Truro. Here Vic carries out a post-mortem investigation which determines the cause of the otter's death and also provides valuable information regarding its physical condition while alive. Tissue samples are also collected for use by other researchers, such as Karen Coxon of Exeter University who is carrying out research in DNA fingerprinting.

Vic has recently provided an interim report on the causes of death of the otter corpses he examined in 2002 (a total of 81 otters, some of which had died prior to 2002 and had been kept in a deep freeze). As might be expected the report makes rather grim reading but it provides an insight into the hidden world of the otter about which we would probably otherwise be unaware.

Not surprising by far the commonest cause of death was as the result of a road traffic injury (71.6% of the sample of 81 otters examined). However a large number of otters showed evidence of bite wounds (with male and females in almost equal proportions of around 40%).

In about a third of these cases the bites had led to septicaemia and this was the cause of death. In most cases the bites resulted from rival otters fighting one another but some appeared to have be caused by mink.

These two causes accounted for the great majority of deaths. Two otters had been killed by dogs, one had been run over by a train, one had died of stress or exposure, another had drowned and one unfortunate otter had a stick trapped in its mouth, presumably preventing it from feeding. Two cubs had been 'killed by man'. The details of this incident are worth quoting in full ad they show what can be done to find the 'culprit':

'A pregnant otter found on a cliff on the North coast of Cornwall had severe head injuries. The lesions were not typical of those found in road accidents and it was suspected that the animal may have been deliberately killed. Shortly afterwards, officers of an animal welfare organisation visited a commercial carp fishery and found a wire snare on the premises. The snare had hairs trapped in the strands and was presented to the Wildlife V I C for examination. Microscopic examination indicated that it was almost certainly otter hair. Samples were then sent for DNA analysis and this confirmed the hair was from an otter. Subsequently, tissue from the otter found on the cliff was also submitted to see if a match could be made with the hair from the snare. Initial results have been promising but further test are proceeding.'

Peter Irvine

One fisherman helps another...

There are still repercussions from the Foot & Mouth outbreak in 2001; cattle now graze the meadows on the Upper Water, which were traditionally grazed by sheep. To help stop these bovine bank and habitat destroyers, the Club has erected a permanent fence along the main river. Fences are expensive and the £1,000 raised from the Wild Trout Trust rod raffle was the catalyst for this project (The rod was kindly donated to the Wild Trout Trust by makers Thomas and Thomas). This new fence will mean more work for the River Keeper and his mower, but a better habitat for flora, fauna and of course salmo trutta!

River Frome otters will also be benefiting from the fence, in one of the small coppices along this stretch, in conjunction with the Dorset Wildlife Trust, We have built a log pile otter holt. It may seem strange that anglers are keen to help otters, yes they eat fish, but they are an important part of the riverside experience. Rivers fly-fishing does have a lot of quiet moments 9more than most in my case!). These precious moments are used by the angler to soak in their milieu and any contribution that will increase the chance of catching a glimpse of an otter, or even a mermaid, will be worth the effort.