Rocky shores in Sullom Voe were first surveyed in 1976 and, apart from a break of two years (1982–83), have been surveyed annually since. The aim of the surveys is to monitor the health of the rocky shore communities by identifying any major changes in the abundance of the fauna and flora and distinguishing anthropogenic effects from natural fluctuations. The 23 primary sites are spread around Sullom Voe, from Mavis Grind, at the head, to Mioness, just outside the entrance. A belt transect method is employed, and categorical abundances of conspicuous species on a checklist are recorded. Graphical analysis of the data for selected species and sites is presented to illustrate the most important changes that have been observed.
The rocky shore communities in Sullom Voe are dynamically stable, except where physical disturbance has not allowed them to reach a state of long-term stability. The effects of, and the recovery from, the 1979 Esso Bernicia oil spill and its clean-up are described. While recovery of communities was rapid on shores where no clean-up was attempted, the communities on shores which were mechanically cleaned were showing continued effects in 1993. The deterioration of dogwhelk populations affected by the antifouling paint additive tributyltin (TBT) has been followed in recent years. Dogwhelk populations close to the terminal jetties are very small and are dominated by adults. Natural fluctuations in abundances of barnacles, dogwhelks, limpets, fucoid algae and littorinid gastropods over the period 1976 to 1992 are also described.