Vertebrate species: mammals

1355 Otter    Lutra lutra   
   Follow link for UK biodiversity information on this species.

Background to selection

Distribution of SACs with species 1355 Lutra lutra.  Click image for enlarged map.
Distribution of SACs with species 1355 Lutra lutra. Click image for enlarged map.

Description and ecological characteristics


The otter Lutra lutra is a semi-aquatic mammal, which occurs in a wide range of ecological conditions, including inland freshwater and coastal areas (particularly in Scotland). Populations in coastal areas utilise shallow, inshore marine areas for feeding but also require fresh water for bathing and terrestrial areas for resting and breeding holts. Coastal otter habitat ranges from sheltered wooded inlets to more open, low-lying coasts. Inland populations utilise a range of running and standing freshwaters. These must have an abundant supply of food (normally associated with high water quality), together with suitable habitat, such as vegetated river banks, islands, reedbeds and woodland, which are used for foraging, breeding and resting.

European status and distribution


The otter Lutra lutra was once widespread in Europe, but populations declined sharply during the 1960s and 1970s due to pollution, exacerbated by hunting and habitat loss. Currently it has a rather discontinuous distribution with strong populations in Greece, Spain, Portugal and much of eastern Europe. Over most of continental western Europe the species is scarce to extinct, but reintroduction or restocking projects are in progress in several countries.

UK status and distribution Click to view UK distribution of this species


Historically, otters Lutra lutra occurred over most of the UK. However, persecution, habitat loss and, more recently, the impact of toxic organochlorine insecticides caused a marked reduction in the range of the species. At present, the majority of the otter population in Great Britain occurs in Scotland, with a significant proportion of this number being found in the north and west of the country. Other strong populations survive in Wales and Ireland. The otter is still scarce over much of England, where the highest concentrations are in the south-west. However, recent surveys suggest that the otter population is recovering well and recolonising parts of its former range.

Site selection rationale


The SAC series reflects the present discontinuous distribution of otters Lutra lutra in the UK. Sites that are known to support high densities have been selected to represent the current strongholds of the population. The sites selected also cover the ecologically variable conditions in which the species is found across its range. As well as a known high density of otters, sites selected have good quality habitat features necessary for feeding and breeding. This is demonstrated by a known record of continuous occupation of the site, even, in England, during the period of population decline. Recent research has demonstrated that this approach has also ensured good coverage of the main lines of genetic variation in British otters.


The otter population is widespread and individuals are wide-ranging, normally occurring at low densities, which is reflected in the relatively large number of sites where the species occurs as a qualifying feature, but is not a primary reason for site selection. The selected sites include some very extensive areas (totalling over 175,000 ha). While the SAC series makes a contribution to securing favourable conservation status for this Annex II species, wider countryside measures, in particular Biodiversity Action Plan implementation, additionally contribute to conservation of this species in the UK.

Site accounts

Afon Teifi/ River Teifi Caerfyrddin/ Carmarthenshire; Ceredigion; Penfro/ Pembrokeshire
The Teifi in west Wales holds otter Lutra lutra throughout much of its catchment. The river has suitable resting and breeding sites along its length. Evidence from surveys and sightings suggest the tidal reach is being increasingly used by otters.
Afon Tywi/ River Tywi Caerfyrddin/ Carmarthenshire
The Afon Tywi is one of the best rivers in Wales for otters Lutra lutra. There are abundant signs of otters and they are regularly seen on the river. The water quality is generally good and there is an ample supply of food. There are suitable lying-up areas along the river bank, but there few known breeding sites on the main river, although cubs have been seen.
Afonydd Cleddau/ Cleddau Rivers Ceredigion; Penfro/ Pembrokeshire
The Eastern and Western Cleddau Rivers flow through a largely lowland landscape, eventually joining and flowing into Milford Haven, which is part of the Pembrokeshire Marine cSAC. These slow-flowing rivers have a diversity of bank-side habitats, and good water quality ensures good stocks of otter Lutra lutra prey species. The otter population on these rivers has shown excellent signs of recovery during the last 1020 years.
Caithness and Sutherland Peatlands Highland
This extensive site contains numerous lochs, lochans and extensive areas of headwaters of burns and rivers. There is extensive habitat suitable for otters Lutra lutra and this is reflected in the presence of a good population, representative of the northern mainland of Scotland.
Cors Caron Ceredigion
Cors Caron is one of the largest wetland areas in Wales and feeds into the River Teifi. Historically it is a very important site for otters and has been an important source of breeding otters Lutra lutra for the River Teifi and probably other catchments such as the Severn and Dovey. Cors Caron provides a very important amphibian food resource for breeding otters in spring.
Dornoch Firth and Morrich More Highland
Dornoch Firth and Morrich More consists of an estuarine system with extensive areas of bordering natural habitat including sand dune, woodland and small lochans. The River Evelix and the River Oykel, which both feed into the site, provide further otter Lutra lutra habitat. The area supports a good population of otters in what is the only east coast estuarine site selected for the species in Scotland.
Insh Marshes Highland
The Insh Marshes are a component part of the River Spey. These extensive marshes together with their lochs, small lochans and ditches provide ideal feeding, resting and shelter areas for otter Lutra lutra and support a good population which is linked to that of the important River Spey population.
Inverpolly Highland
Inverpolly contains extensive areas of large lochs and small lochans together with numerous small river and burn systems as well as an extent of coastline. It forms a large productive area which provides all aspects of otter Lutra lutra needs and supports a high-quality population representative of north-west Scotland.
Loch Maree Complex Highland
This site contains the large freshwater waterbody of Loch Maree with its numerous heavily wooded islands and areas of fringing woodland and heath. There are also a number of smaller, higher altitude lochans within the site and numerous small streams which hold salmonid fish. The site contains all the necessary requirements for otters Lutra lutra and supports a good population representative of a freshwater loch environment in the west Highlands of Scotland.
Loch nam Madadh Western Isles / Na h-Eileanan an Iar
This large, sheltered maritime area is bordered by an extensive area of shoreline and contains numerous small islets and islands. The area supports a key dense otter Lutra lutra population which is a reflection of the shelter and food availability within this highly productive area.
River Camel Cornwall
The Camel represents otter Lutra lutra in its main stronghold in England in the south-west of the country. Surveys have indicated a dense population along this river. Records show that these populations persisted even during the period when the otter was in serious decline over much of the rest of its range in England, and this area has acted as a nucleus for recolonisation of other parts of England. The river and its tributaries represent the more upland as well as lowland habitat types utilised by otters, satisfying requirements for adequate food supply throughout the year. The wooded lower reaches of the river provide excellent habitat for resting and breeding.
River Dee Aberdeenshire
The Dee is a major east coast Scottish river, which flows uninterrupted for some 130 km from its upland reaches in the high Cairngorms to the North Sea. Surveys have indicated that the otter Lutra lutra is found throughout Dee catchment, from its mouth at Aberdeen to many of the high-altitude lochs. The river system contains extensive areas of suitable habitat for otter feeding, resting and breeding, including watercourses with a high fish biomass and islands and marshy areas for resting. This is a strong, high quality population, representative of north-east Scotland.
River Derwent and Bassenthwaite Lake Cumbria
The River Derwent and Bassenthwaite Lake represent good quality otter Lutra lutra habitat in north-west England. Together, the lake and river represent a wide range of suitable conditions for otters in a relatively upland environment.
River Eden Cumbria
The River Eden provides an example of lowland otter Lutra lutra habitats in north-west England and complements the selection of the River Derwent and Bassenthwaite Lake.
River Spey Highland; Moray; Perthshire
The Spey represents an important otter Lutra lutra site in Scotland, with good quality freshwater habitat. Surveys have identified high levels of otter presence throughout the Spey catchment. Riverine habitat features which are known to be important to otters are present, such as reedbeds and islands, and populations of important prey species are relatively healthy. The persistence of a strong population of otter on this river indicates that habitat conditions are particularly favourable for the survival of the species.
River Tweed Northumberland; Scottish Borders
This large river system contains extensive water and riparian habitat suitable for otters Lutra lutra. The extensive tributary burns provide good feeding habitat. The area provides extensive suitable habitat for all the necessary aspects of otter’s life cycle and the site is a good representative of the south-east lowlands of Scotland and the north-east of England.
River Usk/ Afon Wysg Casnewydd/ Newport; Fynwy/ Monmouthshire; Powys
The River Usk is an important site for otters Lutra lutra in Wales. They are believed to be using most parts of the main river, from Newport upstream, and in recent years signs of otters have increased. In 1991 an expansion upstream of known otter ranges was recorded on several tributaries, including the Honddu, Senni and Crai. The upper Usk may have acted as a ‘refuge’ during the decline of the 1950s, and had subsequently acted as a ‘source’ population for recolonisation of south-east Wales.
River Wye/ Afon Gwy Fynwy/ Monmouthshire; Gloucestershire; Herefordshire; Powys
The Wye holds the densest and most well-established otter Lutra lutra population in Wales, representative of otters occurring in lowland freshwater habitats in the borders of Wales. The river has bank-side vegetation cover, abundant food supply, clean water and undisturbed areas of dense scrub suitable for breeding, making it particularly favourable as otter habitat. The population remained even during the lowest point of the UK decline, confirming that the site is particularly favourable for this species and the population likely to be highly stable.
Rum Highland
This island contains numerous freshwater lochs and lochans at a range of altitudes from near sea level to over 400 m, a wide range of small rivers and streams, and an extensive area of coastline. The site provides the full range of marine and freshwater requirements necessary for otter Lutra lutra including breeding, feeding and resting sites. Rum’s otter population is representative of otter populations throughout the Small Isles and Inner Hebrides.
Sunart Highland
Sunart supports a relatively high density of otter Lutra lutra. Records show that the site has supported consistently strong populations, indicating that the habitat is suitable for the species. The site is representative of coastal otter populations on the west coast of Scotland, which is a stronghold for the species. The otters mainly forage in the extensive wrack and kelp beds that occur throughout shallow areas of Loch Sunart and which serve as habitat for important prey species. Over 1400 otter holts, typically in areas of dense vegetation and rock boulder cover, have been recorded in the terrestrial areas bordering the edge of the loch and on the main islands. There is also a large influx of freshwater from numerous streams and rivers around the site which are important to the otter for washing.
Upper Lough Erne Fermanagh
This site represents otter Lutra lutra in Northern Ireland. The province holds one of the strongest populations of otters in the UK. Upper Lough Erne consists of a large eutrophic lake with very extensive associated wetland habitats that holds a dense and large population of otters. In addition the surrounding countryside is rich in relatively unpolluted rivers and lakes and has a high density of semi-natural habitats, especially wetlands, supporting the otter population within the site.
Yell Sound Coast Shetland Islands
The otter Lutra lutra population in Shetland is one of the most intensively-studied in Europe. Not only are the Shetland animals morphologically distinct from their mainland counterparts, they are also believed to be genetically distinct. In addition, specialists consider that the populations are possibly the densest in Europe. Therefore, the Shetland population is in many ways unique, and is considered of special importance in a UK context. Within Shetland, the Yell Sound area has the highest density of otter. Indeed the site is believed to support more than 2% of the entire GB otter population. The site consists of a complex of islands and coastline, selected to include the areas of highest otter density. The areas are characterised by low-lying peaty coastlines with large numbers of otter holts and easy access to fresh water. The adjacent marine areas have extensive algal beds which are used for foraging.

SACs where this Annex II species is a qualifying feature, but not a primary reason for site selection

Afon Eden - Cors Goch Trawsfynydd Gwynedd
Afon Gwyrfai a Llyn Cwellyn Gwynedd
Ardvar and Loch a' Mhuilinn Woodlands Highland
Ballochbuie Aberdeenshire
Cairngorms Aberdeenshire; Highland; Moray
Carmarthen Bay and Estuaries/ Bae Caerfyrddin ac Aberoedd Abertawe/ Swansea; Caerfyrddin/ Carmarthenshire; Penfro/ Pembrokeshire
Dartmoor Devon
Dunkeld - Blairgowrie Lochs Perth and Kinross
Durness Highland
Exmoor and Quantock Oakwoods Devon; Somerset
Foinaven Highland
Glen Beasdale Highland
Glen Creran Woods Argyll and Bute
Glen Tanar Aberdeenshire
Hascosay Shetland Islands
Kinloch and Kyleakin Hills Highland
Lewis Peatlands Western Isles / Na h-Eileanan an Iar
Loch Etive Woods Argyll and Bute; Highland
Loch Fada Argyll and Bute
Loch Lomond Woods Argyll and Bute; Stirling; West Dunbartonshire
Loch Moidart and Loch Shiel Woods Highland
Loch of Isbister Orkney Islands
Loch Ruthven Highland
Lower Derwent Valley East Riding of Yorkshire; North Yorkshire; York
Merrick Kells Dumfries and Galloway; East Ayrshire; South Ayrshire
Moine Mhor Argyll and Bute
Morvern Woods Highland
Muir of Dinnet Aberdeenshire
Mull Oakwoods Argyll and Bute
Ness Woods Highland
North Harris Western Isles / Na h-Eileanan an Iar
North Norfolk Coast Norfolk
Owenkillew River Tyrone
Pembrokeshire Bat Sites and Bosherston Lakes/ Safleoedd Ystlum Sir Benfro a Llynnoedd Bosherston Penfro/ Pembrokeshire
Pembrokeshire Marine/ Sir Benfro Forol Penfro/ Pembrokeshire
Pen Llyn a`r Sarnau/ Lleyn Peninsula and the Sarnau Ceredigion; Gwynedd; Powys
Rannoch Moor Argyll and Bute; Highland; Perth and Kinross
River Borgie Highland
River Dee and Bala Lake/ Afon Dyfrdwy a Llyn Tegid Cheshire; Ddinbych/ Denbighshire; Gwynedd; Shropshire; Sir y Fflint/ Flintshire; Wrecsam/ Wrexham
River Derwent East Riding of Yorkshire; North Yorkshire; York
River Faughan and Tributaries
River Foyle and Tributaries Tyrone
River Itchen City of Southampton; Hampshire
River Mease Derbyshire; Leicestershire; Staffordshire
River Roe and Tributaries Londonderry
River Tay Angus; Argyll and Bute; Perth & Kinross; Stirling
South Uist Machair Western Isles / Na h-Eileanan an Iar
Strathglass Complex Highland
Taynish and Knapdale Woods Argyll and Bute
Tayvallich Juniper and Coast Argyll and Bute
The Broads Norfolk; Suffolk
The Wash and North Norfolk Coast Lincolnshire; Norfolk
Upper Ballinderry River Tyrone

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.