©BSNHS 2014

The return of the Otter.


The last otter disappeared from the River Stort in the late 1950s-early 1960s. The Eastern Counties Otter Hounds used to meet regularly at Harlow Bridge up until this time. They never considered the Stort to be a great otter river and used to go up the Pincey Brook, to the Osier Beds at Pishiobury and then be taken up to Hallingbury Mill where they would investigate the backwaters around Tednambury Farm. The head of one of the last otters on the river is to be found in the lobby at New House Farm, Sheering where the farmer was a great hunter.

It is strange to think at that time, that nobody bemoaned the disappearance of the otter and it just seems to have been accepted. What people did not realise of course was that the environment had been poisoned with organochlorine pesticides including DDT. The otter being at the top of the food chain accumulated a large amount of these chemicals in its system resulting in infertility and death.

No real further thought was given to their return until in the early 1990s the Otter Trust, created by Philip Wayre in Suffolk with the aim of captive breeding otters for reintroduction, released a trio of animals at Hallingbury Mill. The introduction was undertaken at the instigation of Mrs Wilkinson, the owner of the mill who had visited the Otter Trust and offered the river as a site for a reintroduction. Three animals were placed in a release pen in early 1992. It is understood that they broke out on the first night and that the male was killed soon after, trying to cross the Causeway in Bishops Stortford. At about this same time there was another release down at Amwell near to the confluence of the Stort and the Lee.

The releases were not without their critics. People said that to release a top predator into an ecosystem without any prior research as to the suitability of the river and its ability to support these animals was irresponsible, both to the otters and to the environment. Although by that time, organochlorine pesticides had been banned it was thought that there was a high level of PCB’s in the river which was thought to have an affect on male fertility. I found myself being very surprised to be finding otter spraint at all sorts of places up and downstream of Sawbridgeworth. One of the reliable places was where a large willow had fallen across the backwater at the Sawbridgeworth Marsh Nature Reserve. My notebook shows that I continued to find spraint evidence until 1995 when there is no more mention and it was assumed that the animals had died out.

The story takes up again when I volunteered to help with the Essex Otter Survey in 2005. It was apparent that otters were returning of their own volition to Essex Rivers and I was given several locations to check for spraint. Most of these were negative but I did find my own spraint sites down at Eastwick and it was apparent that an animal was coming into the river on a fairly regular basis probably from the Lee Valley. There was no evidence that it was travelling further up river although in retrospect this may have been so. In the Spring of 2014 we had some large floods and after the weather had settled down I “created” a spraint site at the Sawbridgeworth Marsh Nature Reserve where a large willow had fallen across the river. By clearing away flood debris, Stinging Nettles and Cow Parsley I made what looked like an inviting spraint site. Low and behold! Within a fortnight Otter spraint appeared. A strategically placed trail cam caught the otter several times in the next two weeks. Since this time an otter has also been caught on a trail cam at the Thorley Wash Nature Reserve and it looks as if there is at least one animal established in the Stort Valley. The exciting thing is that this animal has either come from one of the Essex Rivers which means that it must have somehow or other negotiated the M11 motorway which forms a not inconsiderable North South

barrier or it has come up from the Lee Valley which means that it must also have passed through areas of riverside development in Harlow. The other vague possibility is that it could have come from the headwaters of the Stort above Bishops Stortford but such is the level of development in the Town Centre that is almost inconceivable that an animal would want to pass through such an urban environment. Once again, the appearance of this gold standard indicator of biodiversity is not without its critics, this time the angling community. In the 1950s, the presence of an otter on the river was accepted and as a fisherman myself I never heard any criticism of them but now that fishing clubs have lakes stocked with large and expensive fish then this has become more of an issue. As yet, there does not seem to have been any serious trouble at any of the fishing lakes but the anglers make their attitude very clear which is a great shame since the presence of the Otter on the river means that not only must the water be clean and pollution free but also in a good enough condition to support a top end predator. I always considered that the Stort was barely large enough to support a single Otter with its home range requirement of something like 15 miles of river. It is possible therefore that what we are seeing is a single animal’s territory and therefore breeding is unlikely although time will tell. Whatever the outcome it is really great to have this iconic mammal back on our river and it is something which I never thought would happen again.