Obain Loch Euphoirt

General site character

• Tidal rivers, Estuaries, Mud flats, Sand flats, Lagoons (including saltwork basins) (100%)
  

Annex I habitats that are a primary reason for selection of this site

• 1150 Coastal lagoons  * Priority feature

  Rock-bound silled lagoons in Europe are virtually restricted to the Outer Hebrides in Scotland, where they are known as oban. Obain Loch Euphoirt (Loch Eport) is one of two sites selected in North Uist to reflect this centre of distribution. Obain Loch Euphoirt lagoons forms one of the most extensive and diverse systems of Coastal lagoons in the UK. The only comparable site is Loch nam Madadh, which has also been selected. The site is a complex of four individual lagoons, which together support the complete range of physical conditions and communities characteristic of this part of Scotland. Loch Obisary is a silled lagoon and is unique amongst the brackish basins of the UK on account of its size, depth (over 40 m), permanent hydrographic stratification and the range of communities it supports. There is a zonation of species within the loch. Several algal species are restricted to within 200 m of the sea water entrance channel. Some, such as Phyllophora pseudoceranoides, are abundant on shallow rock close to the inlet and dominate deeper water throughout the loch. This deeper rock also supports marine ascidians, and there are beds of the freshwater species fennel pondweed Potamogeton pectinatus in shallow water with a greater freshwater influence. Oban nam Fiadh is an extensive system of sluiced lagoons consisting of a series of basins separated by channels and sills with a full transition from marine to freshwater conditions. There is a transition from plant communities typical of fresh or brackish waters, occurring in the inner basin, through distinctive brackish communities including the nationally scarce foxtail stonewort Lamprothamnium papulosum, to marine communities with fucoid algae at the entrance to Loch Euphoirt. Beds of eelgrass Zostera spp. and tasselweed Ruppia spp. occur, supporting the opisthobranch mollusc Akera bullata. The smaller Oban Sponish is a silled lagoon separated from Loch Euphoirt by a boulder sill. There are two basins. Of particular note in the inner basin is a brackish/marine community of a dense bed of eelgrass Zostera marina and tasselweed Ruppia spp. supporting the opisthobranch mollusc Akera bullata. The outer basin supports communities more typical of those found in very sheltered marine conditions. A fourth lagoon in this site is the small brackish silled lagoon, Baigh Uaine, west of Loch Euphoirt. It has a mud floor that supports a dense bed of tasselweed Ruppia spp. The rocky intertidal zone and the sill support characteristic marine fucoid algae.

Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site

• Not Applicable

Annex II species that are a primary reason for selection of this site

• Not Applicable

Annex II species present as a qualifying feature, but not a primary reason for site selection

• Not Applicable