Surveys of the intertidal macrofauna and sediment characters of Nigg Bay, Moray Firth, were carried out between 1981 and 1985. Permanent stations were located at the intersections of a half-kilometre grid covering the entire intertidal area and sampled for infauna, using replicate cores. Estimates were also made of mussel and lugworm densities from quadrats and cast counts respectively. The biomasses of selected species that constitute important resources for higher trophic levels were also estimated. The sediment for each station was analysed for median particle diameter and silt content.

The infaunal data were analysed by Detrended Correspondence Analysis. This indicated that tidal height was the most important factor governing the distribution and abundance of the intertidal communities. Sediment characters were only poorly related to distribution patterns.

The bay has a rich fauna and is biologically similar to other outer bays of the Moray Firth, which, like Nigg, are important areas for wildfowl and waders. Comparisons of survey data from different years indicate that there are natural cycles in some sediment and biological characters of Nigg Bay.