The Ouse is a tidal

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...

in northern

Shapinsay Shapinsay (, ) is one of the Orkney Islands off the north coast of mainland Scotland. With an area of , it is the eighth largest island in the Orkney archipelago. It is low-lying and, with a bedrock formed from Old Red Sandstone overlain by bo ...

Orkney Islands Orkney (), also known as the Orkney Islands, is an archipelago off the north coast of mainland Scotland. The plural name the Orkneys is also sometimes used, but locals now consider it outdated. Part of the Northern Isles along with Shetland ...

. This water body has been shown on early maps of the island in a very similar shape to its current geometry. The Ouse is fed by small rivulets and upland springs that rise on the western part of the island's northeast spur. pH levels of these feed waters are moderately

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

, in the range of 9.1.C.M Hogan, ''Natural History of the Orkney Islands'' (2006)

Footnotes

Shapinsay {{Orkney-geo-stub

See also

Footnotes