The first phase of the SWCS in 1989, examined the assumption that submerged crannogs were relatively stable, while their counterparts on dry land were rapidly decaying.
The work obtained clear indications of the accelerated organic decay of sites on dry land and, most importantly, demonstrated that submerged sites were suffering from the infestation of underwater plant and animal life due to high levels of biological activity present in certain lochs.
The results of the 1989 survey indicated therefore that crannogs in South-West Scotland, both on dry land and underwater, are undergoing organic decay on a scale that is significantly devaluing their potential archaeological value. However, it was not possible to fully establish the condition of the surviving crannogs by superficial examination alone and no attempt was made to assess their stability.
The aim of the second phase of the SWCS, which began in 2002, was to establish an effective system of monitoring the rate of organic decay on crannog sites in different environments (submerged and on land) in an effort to provide accurate data on the sustainability of the crannog resource throughout South-West Scotland. This long-term monitoring will identify the mechanisms and causes of organic decay in the area. Using the information gathered during this survey, appropriate management strategies can be designed to ensure the maximum preservation of crannog sites in the South-West.
The crannogs of South-West Scotland are usually envisaged as 'packwerk' mounds made up of layers of peat, timber and brushwood to provide an artificial island for a timber superstructure contrasting with the stone and boulder mounds found in the Highland regions north of the Clyde (see Henderson 1998, 236).
The systematic surveys carried out during the SWCS have revealed that there is a far greater diversity of constructional forms present in the South-West than has previously been recognised (Henderson et al. 2003). While 'packwerk' mounds exist there are also sites which feature a substantial stone element in their construction or that appear to be completely constructed out of stone with a stone superstructure on top.
Overall, the findings of the SWCS challenge simplistic definitions of crannog form and question the relevance of previously held type boundaries. The perceived differences between the Highland and South-West sites may be more attributable to the lack of underwater survey carried out nationally as many of the key identifiable characteristics of sites noted during the SWCS can only be seen under water. The perceived differences between Highland and South-Western sites may have more to do with the widespread drainage and improvement operations in the latter area than any significant cultural structural or chronological variation. Equally the more widespread occurrence of exposed organics and structural timber on submerged sites in the South-West may be attributable to the smaller size and less active tidal regimes of those lochs compared to the much larger and more turbulent Highland lochs.
HENDERSON, J. C. 1998. Islets through time: the definition, dating and distribution of Scottish crannogs. Oxford Journal of Archaeology, 17:2, 227-244.
HENDERSON, J.C., CRONE, B.A., AND CAVERS, M.G., 2003. A condition survey of selected crannogs in south west Scotland. Transactions of the Dumfriesshire and Galloway Natural History and Antiquarian Society, 77, 79-102.
HENDERSON, J.C., 2004. The Scottish Wetland Archaeology Programme: Assessing and Monitoring the Resource. Journal of Wetland Archaeology, 4, 169-182.
HENDERSON, J.C., CAVERS, M. G., AND CRONE, B. A., 2006. The South West Crannog Survey: Recent work on the lake dwellings of Dumfries and Galloway. Transactions of the Dumfriesshire and Galloway Natural History and Antiquarian Society, 80, pp. 29-52.
HENDERSON, J.C., 2007. Recognising complexity and realizing the potential of Scottish Crannogs. In: BARBER, J., CLARKE, C., CRONE, A., HALE, A., HENDERSON, J., HOUSLEY, R., SANDS, R., SHERIDAN, A., eds. Archaeology From The Wetlands: Recent Perspectives. Edinburgh: Society of Antiquaries of Scotland. pp. 231-241.