The Recovery of the Otter in Christchurch Harbour

Over the last few months, under the guidance and training of the Dorset Otter Group, Tony Astridge has been monitoring Christchurch Harbour for evidence of Otter. This works involves weekly checks of 23 points on Stanpit and 4 on Hengistbury in search of spraints. Excitingly, in the last few weeks, spraints have been found at 2 locations on Stanpit and by the HHC; while in early September single Otter were actually seen at two locations just outside the recording area. There is now significant evidence to show that Otter are returning to the waters of the harbour.

Otter have large, riverside territories, sometimes up to 30 kilometres in length. The animals in the harbour are presumably at the southernmost tip of territories on the Avon and Stour. Nationally, Otter populations are on the recovery after human persecution and river pollution from pesticides. Killing of Otter was outlawed in 1978 and, in conjunction with the tightening of pesticide laws in 1982, a slow recovery was triggered. It is estimated the population has increased by 300% since 1976. Dorset has always played host to small, isolated populations on both the Stour and Avon, with the greater numbers on the former.

Not to be confused with the also present Mink, Otter are between 1m and 1.2m in length and can weigh up to 10kilograms. Overall coloration is a uniform, medium to dark brown, with a paler throat and, occasionally, a white chin spot. Head shape is flat with prominent whiskers, while the tail is proportionately long to the body, about 30% of the total. When swimming, they create a V-shaped wake.

In the last couple of weeks, evidence of Water Vole has been found in Purewell Stream. This is a nationally declining species that can only survive in pure water.

Many thanks to Tony Astridge for supplying the information about Otter.