Otter (Lutra lutra)

The Eurasian otter  is one of the larger British mustelids. On average male otters can be up to 1.2m long from nose to tail and weigh up to 12kg with the females being smaller. During the 1950s to the 1970s there was significant decline in the otter population as a result of pollution and extensive use of organochlorine pesticides, however, the otter population within the UK is steadily increasing/recovering as a result of better river quality. 

Otters can be found in a diverse wetland habitat for breeding, feeding and resting, such as, rivers, streams, lochs, marshes, ditches, coastal areas, wetlands and estuaries. Otters are mainly active at night (nocturnal), resting during the day in holts underground (or under tree roots near river banks and cavities under bridges) or in hovers (or couches) above ground, so they can be quite elusive and seldom seen. The otters home range can be extensive, up to 40km, encompassing a variety of habitats including resting places and areas of refuge. Breeding can occur throughout the year with 1 to 4 cubs being raised. The cubs stay with the mother for approximately a year before leaving to establish their own territories.

GLM Ecology has extensive experience in otter surveys. This involves the identification of field signs, such as, footprints and spraints, including key foraging and commuting habitat.  Due to otters being highly mobile and wide ranging a typical otter survey will involve the immediate watercourse possibly affected by development and also an additional 2km upstream and downstream. Otter surveys are not seasonally constrained but are less complicated during summer and autumn.

Legislation

Otters and their habitats are fully protected under both UK and European legislation under the Wildlife and Countryside Act 1981 (as amended) and  the Conservation Regulations 1994.There are designated areas of protection, but even outside of these sites, otters and their holts are fully protected. It is an offence to kill, injure or knowingly disturb an otter; to take an otter from the wild; to damage/obstruct a place of otter shelter/protection; and to disturb an otter while in a place of shelter. The otter is a Priority Species under the UK Biodiversity Action Plan and there is a national Species Action Plan (SAP) for its conservation (Species of Principal Importance in England under Section 41 of the NERC Act 2006 (Section 42 in Wales) and the Conservation (Scotland) Act in Scotland). It is government policy that local authorities protect such species from the adverse effects of development.

Mitigation

Developers should have an otter survey carried out prior to obtaining any planning permission. A European Protected Species licence is required whenever disturbance to otters or damage to their holts/couches is likely to occur, prior to any development. The nature of the development will determine the type of mitigation to be carried out. If otters are present planning permission can be refused unless the developers can clearly demonstrate that the otters will be protected during the development process and disturbance kept to a minimum. Modifications to site practice and layout may be involved. If habitat is to be lost, this may include habitat creation involving artificial holt construction along watercourses. Traffic mortality is a significant threat to otter populations and so otters must be discouraged from using roads. For road schemes ramps and culverts will have to be constructed above high water level, under bridges, to allow otters passage as they are forced upwards, and to dissuade them from using the road during these high river flow times.The overall objective is that otter habitat is maintained.