Natural environment of the Forth


The Forth of Forth, on the east coast of Scotland, is a sheltered arm of the North Sea and the estuary of the River Forth. From the tidal water limit at Stirling to the Isle of May the Forth is 96km long and covers an area of 1,670km2. At Stirling the waters are shallow and brackish i.e. a mix of sea and freshwater from the river. Expanses of mudflats exposed at low tide are rich feeding areas for birds. Further down the narrow channel between North and South Queensferry has been bridged first by the Forth Rail Bridge and then later by the road bridges. A deep channel allows large ships to pass under the bridges to the ports of Rosyth and Grangemouth. Further down the Forth widens out and the shores become sandy and rocky interspersed with fishing villages. Golf courses have traditionally been created on the sandy grassy links in Fife and East Lothian.

The Firth of Forth is the only area in the east coast with offshore islands. The largest of these is the Isle of May, an important seabird breeding habitat. There are around 12 islands.


The Firth of Forth estuary has a great variety of natural habitats including inter-tidal habitats such as mudflats, saltmarsh and reedbed, which are wonderful places for wildlife. When the mudflats of the Upper Forth are exposed at low tide they burst in to life, particularly during winter when the Forth becomes home to thousands of wading birds such as redshanks, knots and dunlins and oystercatchers. The wealth and diversity of plants and animals to be found in these habitats make the Forth an internationally important wintering site for birds travelling from as far afield as Scandinavia, Iceland and the Arctic.

Watching these waders during the winter can be an exhilarating experience and the mudflats around Cramond and Bo’ness are excellent places to spot a range of species. If you are lucky you might see the spectacular sight of peregrines hunting along the shoreline, often sending thousands of birds in to the sky at one time.

It’s not just the winter where you can see fantastic wildlife however, in summer flocks of non breeding mute swans congregate at the mouths of the River Esk at Musselburgh and River Almond at Cramond. Saltmarsh, an increasingly rare habitat within the Forth estuary, can be strikingly beautiful at the height of summer while the The coastal grasslands and dunes in Fife and East Lothian are home to many flowering plants and grasses some of which are nationally rare. The dune system extending from Aberlady to Yellowcraigs is the largest in the area. The most natural section is found between Jamie’s Neuk and Eyebroughy island. Here you can easily see the full sequence of dune habitats from strandline and embryo dunes through to stable dune grasslands.

Away from the inter-tidal habitats, the rocky islands of the Forth estuary provide safe breeding areas for many thousands of sea birds including puffins, gannets, fulmars, guillemots and razorbills. Some of the islands have been invaded by a plant called tree mallow which is preventing puffins in particular, from reaching their nesting burrows. Volunteers are working to remove tree mallow from nesting sites.

The marine environment is also important and the undersea habitats around the rocky islands support many species such as sponges, anemones and sea slugs. The waters around the Isle of May are home to beautiful rocky reefs. Much of the estuary is surprisingly shallow, particularly on the southern shores where large mud and sandflats extend out from the coast.

Traditionally fishing depended on the harvest of mussels, oysters, scallops and herring. These industries have largely collapsed but the Forth is showing signs of recovery and is a nursery ground for species such as flounder and a wintering area for herring and sprats. Salmon migrate along the coastline to gain access to upper reaches of the Forth for breeding.

Seals are a common sight in the Forth. Most are grey seals with their distinctive ‘Roman’ noses. Grey seals give birth in November at various rocky locations and islands including the Isle of May. Grey seal population levels are robust, this combined with their curious nature means you will often see them if you are on the sea, particularly around the Forth’s islands and rocky outcrops.

Harbour seals also use the Forth, pupping in the summer. The pups can swim almost immediately which means pupping sites can be found next to deep water. The east coast harbour seal population has crashed over the last decade and sadly there are few of these graceful creatures left in the Forth.

Whales and dolphins are also noted on a regular basis. Bottlenose dolphins and harbour porpoises visit the Forth and are regularly seen from boats and from the shore. Occasionally a whale makes it up as far as the Forth Bridge but this is uncommon.

Most of the coastline and the islands are legally protected by national and international wildlife designations. The Sites of Special Scientific Interest (SSSI) protect nationally important habitats, species and geology. The Special Protection Area (SPA) is an international designation which protects important bird species. The Isle of May is a Special Area of Conservation (SAC) because it supports a breeding colony of grey seals making it the largest east coast breeding colony of grey seals in Scotland. These habitats not only bring beauty and life to the landscape, but offer exciting opportunities- including sustainable flood management, climate change mitigation and potential for recreation, tourism and education- that provide real, measurable benefits for the people of the Forth as well.

For more information see


The geology of the Firth of Forth is both interesting and complex.  The area has been well studied since the early days of geological survey in the 18th century.  The estuary was largely created by glaciers excavating deep basins as they scoured the landscape and exploited existing river valleys. Following the last ice age some 7000 years ago, the ice retreated and the sea flooded the Forth valley up to Menteith and Aberfoyle. As the sea retreated the land rose and the flat fertile lands (the Carselands) at the head of the Forth emerged from the water. At first covered in peat, the area was gradually reclaimed to become fertile farmland and subsequently in demand for industrial development and transport links. Further down the coast the underlying coal, oil shale and limestone reserves were close to the shore and were exploited from earliest times.  As the Industrial Revolution gathered pace the reserves of coal and limestone were used to fuel the many industries around the Forth and beyond. The oil shale reserves in West Lothian created the world’s first oil industry and gave the area a head start once North Sea oil came onshore in the 1970’s and 1980’s.

Our members include

View Desktop
View Mobile