The Loch of Stenness is a large

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

loch on

Mainland, Orkney The Mainland, also known as Hrossey and Pomona, is the main island of Orkney, Scotland. Both of Orkney's burghs, Kirkwall and Stromness, lie on the island, which is also the heart of Orkney's ferry and air connections. Seventy-five per cent of ...

, Scotland and is named for the parish of

Stenness Stenness (pronounced ) ( non, Steinnes; nrn, Stennes) is a village and parish on the Orkney Mainland in Scotland. It contains several notable prehistoric monuments including the Standing Stones of Stenness and the Ring of Brodgar. Geography St ...

. It is northeast of the town of

Stromness Stromness (, non, Straumnes; nrn, Stromnes) is the second-most populous town in Orkney, Scotland. It is in the southwestern part of Mainland Orkney. It is a burgh with a parish around the outside with the town of Stromness as its capital. E ...

, lies immediately to the south of the Loch of Harray and is close to the

World Heritage A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...

neolithic sites of the

Stones of Stenness The Standing Stones of Stenness is a Neolithic monument five miles northeast of Stromness on the mainland of Orkney, Scotland. This may be the oldest henge site in the British Isles. Various traditions associated with the stones survived into ...

and

Ring of Brodgar The Ring of Brodgar (or Brogar, or Ring o' Brodgar) is a Neolithic henge and stone circle about 6 miles north-east of Stromness on Mainland, the largest island in Orkney, Scotland. It is part of the UNESCO World Heritage Site known as the ...

. In

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is a stage of development of North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants of Scandinavia and their overseas settlement ...

its name was ''Steinnesvatn''.Pedersen, Roy (January 1992) ''Orkneyjar ok Katanes'' (map, Inverness, Nevis Print)

Hydrography

The Loch of Stenness is a sea loch and is the deepest loch on the Mainland, it is slightly smaller in area and volume than the Loch of Harray. It is located at northeast of

, and is the largest brackish lagoon in the UK."Loch of Stennes"
JNCC. Retrieved 19 June 2011. Its outflow is into the Bay of Ireland and the

Hoy Sound Hoy Sound is a body of salt water subject to tidal currents situated south of the town of Stromness in the Orkney archipelago of Scotland. The sound lies north of the island of Hoy and to the south of Mainland Orkney. To the west are the open w ...

at Brig o’ Waithe where tidal currents influence the loch but cause little variation in its level. The loch is connected to the Loch of Harray at the Bridge of Brodgar"Lochs of Harray and Stenness Site of Special Scientific Interest" Midas 1083. SNH and both lochs together cover an area of making the two combined the ninth largest loch in Scotland by area (as listed by Murray and Pullar (1910)). The Loch of Stenness has a maximum depth of and an average depth of .

Natural history

The Loch of Stenness is important in terms of its biodiversity because of its brackish composition. It has been designated a

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle ...

as well as a

Special Area of Conservation A Special Area of Conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and a ...

. Its varying salt content supports a range of wildlife suited to marine, brackish and fresh water conditions including burrowing worms, bivalves such as

mussels Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which ...

and

mya arenaria Soft-shell clams (American English) or sand gaper (British English/Europe), scientific name ''Mya arenaria'', popularly called "steamers", "softshells", "piss clams", "Ipswich clams", or "Essex clams" are a species of edible saltwater clam, a ...

, the snail

Hydrobia ulvae ''Peringia ulvae'' (or ''Hydrobia ulvae''), common name the Laver spire shell or mudsnail, is a European species of very small aquatic snail with gills and an operculum, a gastropod mollusk in the family Hydrobiidae.Gofas, S. (2010). ''Hydr ...

and various types of green algae known as

charophytes Charophyta () is a group of freshwater green algae, called charophytes (), sometimes treated as a division, yet also as a superdivision or an unranked clade. The terrestrial plants, the Embryophyta emerged within Charophyta, possibly from terres ...

. It provides a wintering ground for a wide variety of

wildfowl The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on ...

including

pochard Pochard is a common name used for several species of diving ducks: *Four species in the genus ''Aythya'': ** Common pochard, ''Aythya ferina'' ** Baer's pochard, ''Aythya baeri'' ** Ferruginous pochard, ''Aythya nyroca'' ** Madagascar pochard, '' ...

, tufted duck,

scaup Scaup is the common name for three species of diving duck: * Greater scaup, or just "scaup", ''Aythya marila'' * Lesser scaup The lesser scaup (''Aythya affinis'') is a small North American diving duck that migrates south as far as Central Ameri ...

and

goldeneye ''GoldenEye'' is a 1995 spy film, the seventeenth in the ''James Bond'' series produced by Eon Productions, and the first to star Pierce Brosnan as the fictional MI6 agent James Bond. Directed by Martin Campbell, it was the first in the se ...

Archaeology

The Watch Stone, Stenness, Orkney - geograph

The Loch of Stenness is adjacent to the World Heritage sites of

and the

. The Watch Stone, a solitary monolith high stands where the loch joins with the Loch of Harray, at Bridge of Brodgar. The loch and its surrounding area underwent detailed

geophysical Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' some ...

and multibeam sonar surveys in 2011 and 2012 to investigate the drowned palaeo-landscape. The surveys indicated significant archaeological features in the loch including a circular structure possibly a

henge There are three related types of Neolithic earthwork that are all sometimes loosely called henges. The essential characteristic of all three is that they feature a ring-shaped bank and ditch, with the ditch inside the bank. Because the internal ...

References

{{reflist * Murray, Sir John and Pullar, Laurence (1910) ''Bathymetrical Survey of the Fresh-Water Lochs of Scotland, 1897-1909''. London; Challenger Office. * This article incorporates text from - Wilson, Rev. John ''The Gazetteer of Scotland'' (Edinburgh, 1882) Published by W. & A.K. Johnstone

Sites of Special Scientific Interest in Orkney Special Areas of Conservation in Scotland World Heritage Sites in Scotland

Mainland, Orkney