Loch nam Madadh

Site details

UK map showing location of Loch nam Madadh Special Area of Conservation/Site of Community Importance.
Location of Loch nam Madadh SAC/SCI/cSAC


When undertaking an appropriate assessment of impacts at a site, all features of European importance (both primary and non-primary) need to be considered.

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. Loch nam Madadh (Loch Maddy) is one of two sites selected in North Uist to reflect this distribution. Loch nam Madadh lagoons form the most extensive and diverse saline lagoon system in the UK. The only comparable site is Obain Loch Euphoirt (Loch Eport), which has also been selected. There are 14 lagoons in the Loch nam Madadh complex. These connect with the extensive system of freshwater lochs and lochans in the North Uist hinterland and the fjardic sea loch of Loch nam Madadh itself. There is a wide range of types, from large, complex lagoons with several sills and basins to small, shallow single lagoons. Together they encompass the full transition from freshwater to marine conditions, through a series of basins and sills, and have an exceptionally wide range of habitat types with associated characteristic communities. Most have one or more basins floored with soft, peaty mud, and there are usually boulders and cobbles around the margins. At the entrances to some of the lagoons there are rock and boulder waterfalls. Others have rock and coarse sediment rapids that flood at all states of the tide, and yet others have a percolation barrier. Within the basins of Loch an Dýin and Loch an Strumore there are beds of dwarf eelgrass Zostera noltei, small patches of eelgrass Z. marina, large quantities of the scarce green alga Cladophora battersii, and the scarce foxtail stonewort Lamprothamnion papulosum. Other lagoons in the complex have tidal rapids with kelp Laminaria spp. and sea-oak Halidrys siliquosa, which supports extensive epiphytic growths of sponges, anemones and ascidians. Others have intertidal rapids dominated by fucoid algae, and in these lagoons, the fan-worm Sabella pavonina is found, associated with areas of coarse sediment. Shallow peaty mud in the basins has large numbers of the burrowing amphipod Corophium volutator and lugworm Arenicola marina, and beds of mussels Mytilus edulis and the green alga Codium sp. are found on hard substrates near the entrance channels.
1160 Large shallow inlets and bays
Loch nam Madadh (Loch Maddy) is representative of fjardic sea lochs on the coast of north-west Scotland. This site is exceptionally complex. It is predominantly shallow, with deeper water only in its entrance, and wave exposure grades from moderately exposed to extremely sheltered in the inner basins. There are numerous rocks and islands and at least 22 shallow sills and associated basins. The fjardic marine biotopes on this site are more diverse than on any other known site in the EU. There is a particularly wide variety of shallow tide-swept reef and sediment habitats and communities. Some of the holothurian species found in abundance on soft mud in the inner basins, such as the sea cucumber Labidoplax media, are considered rare elsewhere. There are dense beds of knotted wrack Ascophyllum nodosum ecad mackaii and a variety of kelp forest types that illustrate the wave exposure gradient in the loch. There are transitions to a complex system of lagoons, which have been selected in their own right as Annex†I type 1150 Coastal lagoons.

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

1110 Sandbanks which are slightly covered by sea water all the time
1140 Mudflats and sandflats not covered by seawater at low tide
1170 Reefs

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

1355 Otter  Lutra lutra
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.

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

Not applicable.

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