Three estuarine firths extend deep into the Highlands – Dornoch, Cromarty and Beauly. These shallow mudflats support mussel beds and expanses of seagrass. The muds are dense with burrowing molluscs, including cockles, baltic tellins, peppery furrow shells and razor shells.
Estuarine mudflats are also found along the south shore of the Moray Firth at Culbin Sands, Findhorn Bay and Spey Bay.
Seagrass beds are found in all the bays from Findhorn Bay to Loch Fleet and provide important feeding areas for shellfish and young fish, and waterfowl. The Moray Firth supports 20,000 to 36,000 wintering waders and 10,000 waterfowl, with many birds using the inner firths as migration staging posts.. The inner Moray Firth is recognised as the most important sea duck site in Britain. The Firth as a whole is in the ten most important estuarine sites in Britain, and is the most northerly major wintering ground for waterbirds in Europe.
Saltmarsh supports some highly specialised plants, including glasswort, full of silica and adapted to a twice daily covering of shallow sea water. Further up the shore flowering plants like sea aster, thrift and sea plantain can survive in the salty air and occasional sea wash.
The mud and sands of the Dornoch Firth and Morrich More near Tain form the most extensive area of glasswort saltmarsh in Scotland. At Morrich More this forms part of a complete transition from glasswort pioneers to upper saltmeadow and important sand dune habitats.
At Nigg Bay, on the Cromarty Firth shore, sea walls were removed by the RSPB in 2003 to allow a natural coastline and saltmarsh habitat to develop. Since then saltmarsh has expanded and mud-dwelling invertebrates (snails, worms and shrimps) have moved back in. Twenty-five species of waterbirds, including redshank, bar-tailed godwit and whooper swan use the bay’s valuable extra feeding areas as the tide comes in and find a safe roost at high tide. During windy conditions and in high spring tides the bay is an essential refuge for up to 2000 waterbirds.
Find out more:
Saltmarsh, SNH website