WILDLIFE AND NATURAL HABITATS OF THE CROMARTY FIRTH
The Cromarty Firth has one of the largest area of intertidal flats within the Moray Basin (from Brora to Spey Bay). The uppermost parts of the Firth are muddy but the sediments become predominantly sandy towards the mouth at Nigg and Udale Bays. These sand and mud flats support a rich and abundant invertebrate fauna as well as mussel beds and extensive growths of Ruppia maritima (tasselweed) and Zostera spp. (eelgrass) in Alness, Nigg and Udale Bays. Alness Bay supports a particularly rich macroalgal flora with 21 species recorded.
Saltmarsh occurs within the estuary, particularly where rivers enter the Firth but nowhere is it very extensive. The most important areas are at the head of Dingwall and Udale Bays, at Alness Point and Nigg Bay and at the Conon Islands. The vegetation at the head of the Firth at the Conon Islands shows the transition from saltings on the outer islands, through herb-rich grassland and fen to woodland. Here, the invertebrate fauna is rich. Of further interest is the shingle bar and coastal lagoon at Alness Point. The shingle spit supports important breeding bird populations.
In contrast to the Firth itself the north and south Sutors are rocky headlands whose maritime cliffs support the only breeding seabird colony in the Inner Moray Firth. The coast to the north and south of the Sutors is also steep and supports other coastal habitats such as grassland and scrub.
The sheltered bays, intertidal flats and saltmarshes within the Cromarty Firth provide roosting and feeding grounds for wintering wildfowl and waders which regularly number in excess of 29,000 birds. The estuary attracts internationally important populations of four species of waterfowl (Icelandic Greylag Goose, Redshank, Wigeon, and Bar-tailed Godwit) and nationally important populations of a further four species (Red-breasted Merganser, Goldeneye, Curlew, and Scaup). In addition smaller numbers of Slavonian grebe, whooper swan, teal, oystercatcher and pink footed geese occur. These waterfowl form major components of the internationally important populations of these species which winter in the Moray Basin as a whole.
A range of breeding birds also occur in the Cromarty Firth, including colonies of herring gull, fulmar, common gull and greater black backed gull. Of particular importance however are approximately 300 pairs of terns which nest in the Alness and Nigg areas. The saltmarshes support small numbers of breeding waders including oystercatcher, redshank, and lapwing. Small numbers of ringed plover also breed within the estuary. The cliffs at the North Sutor support breeding razorbill, guillemot, shag, kittiwake, black guillemot and 4% of the breeding British cormorant population. The estuary also provides foraging grounds for nationally important numbers of breeding osprey.
Additional Wildlife Features
Otters are present on the estuary and between 50 and 100 common seals haul out on the sandbanks east of Cromarty Bridge. In addition a population of bottlenose dolphins regularly visits the Cromarty Firth. This is one of only two known resident populations in the UK and the only resident inshore population in the North Sea.
Most of the intertidal area of the Firth is covered by the Conon Islands (171 ha) and Cromarty Firth (3,585 ha) biological Sites of Special Scientific Interest, which are of national importance. Parts of Nigg and Udale Bays have been declared a National Nature Reserve. The cliffs at the Sutors form part of the Rosemarkie to Shandwick Coast SSSI.
The estuary and the Sutors form part of the proposed Moray Basin, Firths and Bays Ramsar Site and Special Protection Area under EC Directive 79/409 on the Conservation of Wild Birds. The Firth is also part of the Moray Firth possible marine Special Area of Conservation because of its importance to bottlenose dolphins.
There are two RSPB reserves on the Firth, at Udale Bay - where a public hide was installed in 1993 - and Nigg Bay. The southern shore of the Cromarty Firth was designated as a preferred Coastal Conservation Zone in the Oil and Gas Coastal Planning Guidelines (Scottish Development Department, 1974).
In the 19th century there were significant habitat losses due to reclamation for agriculture. This largely resulted in the distribution of habitats which were present before the development of the north sea oil industry. Mainly as a result of major oil-related developments during the seventies and late eighties, some further intertidal habitats have been lost to shore based developments. In particular, facilities at Nigg such as the BP oil terminal and the rig-fabrication yard at Nigg, and the pipeline fabrication yard at Evanton have been built on land reclaimed from intertidal habitats. Some habitat loss has also occurred because of road improvement schemes particularly at the western entrances to Invergordon and Cromarty.
Recreational activities such as sailing, bird watching and coastal walking occur throughout the Firth and are likely to increase. Potential pressure points include, for instance, Alness Point. SNH is currently undertaking a research project to investigate the impact of recreational disturbance on the bird populations of the Firth, the results of which will be available in August 1995.
Wildfowling occurs in the winter particularly in Nigg and Udale bays and at Conon Bridge. At present small numbers of wildfowlers take part and on the whole are responsible and law abiding. However, there are increasing numbers of visiting wildfowlers to the area. There could be a serious threat to bird populations if the wildfowling pressure were to increase significantly. The provision of sanctuary areas for wildfowl has been proposed as beneficial to both the bird populations and wildfowling. In addition birds may be affected by clay pigeon shooting, as practised at Evanton, which not only represents a further disturbance pressure but may also result in significant amounts of lead shot accumulating in intertidal feeding areas.
The commercial collection of cockles is increasing using both land-based and boat based equipment. As controls become tighter and stocks become less abundant both in England and in Europe it is likely that operators will increasingly look to the Moray Firth for business. Cockle stocks in Nigg bay are coming under increasing pressure from fishermen using a range of collection techniques and are seen by the cockling industry as an important source for further exploitation. As well as disturbing bird populations the activity also damages the intertidal habitat and the fauna living within it. It is significant that the activity cannot be controlled at present.