COASTAL ARCHAEOLOGY OF THE CROMARTY FIRTH
Historically, and indeed prehistorically, the Cromarty Firth formed part of a vital highway along the coast of Britain and across the North Sea to Europe and Scandinavia. Access to the sea was important not only for peaceful trade but also because this was how unwelcome visitors such as Viking raiders and settlers, for example, could arrive. The Firth's sheltered situation and large natural harbour are likely to have been particularly important at all periods and its maritime archaeology is expected to be correspondingly rich and generally relatively well protected from erosion processes (compared for example to many west coast areas where there are strong currents and rocky shores).
In addition, the sea provided resources which were important, such as fish and shellfish and other perhaps less obvious things like salt, or seaweed. The development of the fishing industry in the 19th century produced ice-houses, warehouses and smoke-houses and fishertown settlements.
The sediments of the Firth hold not only a record of human artefacts but also a record of past environmental change. Archaeologists are increasingly turning to aquatic sediments to interpret changes in surrounding land use, for example the history of deforestation and agriculture in a catchment area. In this as in many other aspects of its archaeological record, the Cromarty Firth holds exciting potential for research and interpretation.
The information recorded for the intertidal zone or the area below low water in the Cromarty Firth is sparse. Much of it relates to naval vessels and aircraft. However, for the reasons given above the potential of the Firth is high - especially in its more shallow, sheltered areas where natural processes have favoured deposition rather than erosion. Techniques, such as the use of side-scan sonar, could provide much further survey information.
Around the firth itself there are known sites of virtually all periods from Neolithic Henge monuments and cairns to depopulated settlements associated with the Clearances of the 19th century. Particular points of interest in the area include the fact that it is at the centre of a particularly important group of Pictish carved stones including those at Shandwick, Nigg, Dingwall and Rosemarkie, which Ross and Cromarty District Council has promoted through its Pictish Trail. Dingwall was an important Viking centre, although it has been inadequately researched. There are undoubtedly many more sites to be found throughout the Firth and its surrounding area.
The shoreline of the firth features a number of maritime or coastal structures of historical and/or architectural importance. These often vividly illustrate the firth's long history of use: ranging from medieval ecclesiastical remains to piers and 18th century granaries which were used to store estate "rents" prior to their shipment southwards. The frequency of the latter, of which there are listed examples at Foulis, Alness, Invergordon and Ferryton, is particularly distinctive of the area.
The archaeology of the coastal zone is threatened by both natural processes and coastal developments. The coast is subject to a constant process of deposition and erosion of material. Attention is often focused on areas of current erosion, where archaeological sites are falling into the sea (see Cille Bhrea Chapel), but these processes have of course always been going on, and this can affect our interpretation of the surviving archaeology. For example, it is thought that some at least of medieval Cromarty has been lost to the sea over the last 400 years.
Conversely where deposition has occurred, archaeological sites rich in organic remains (such as wooden boats or quays) may survive in waterlogged conditions. These processes do not just affect the shoreline, but the seabed also. Shipwrecks for example will not long survive if they are situated in areas of scour, but if buried can lead to the preservation of a remarkable range of artefacts. An understanding of the natural coastal processes of an area is therefore important in interpreting the archaeology it contains.
The construction of harbours, coastal defences, or oil platforms, dredging and other activities can have an effect on natural erosion and deposition processes - possibly for some distance along the coast. Dredging and other activities associated with the Nigg construction yard and the industries at Invergordon may have caused damage to this archaeological resource but it is difficult to assess. Changing patterns of currents can mean the sudden and rapid disappearance of submerged or coastal margin archaeology which has been in a stable condition for thousands of years. It is therefore important to consider these effects as part of any environmental assessment exercise ahead of new developments.
Sites of historical or archaeological importance can also be lost through a gradual process of attrition and neglect. This is of particular relevance to the Firth's maritime structures such as Balintraid pier and also to the evidence of its importance as a naval base.