Following cessation of sewage sludge disposal at a site ca 2 km from Garroch Head, Isle of Bute, Firth of Clyde (Scotland), a study of the recovery of the benthic environment was undertaken. In order to permit comparisons a reappraisal of data obtained in 1971, whilst the site was still actively in use, was undertaken. Based on the parameters used, the benthic community showed a marked recovery from its status in 1971 and now approaches what should be considered as normal for this slightly enriched area.

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Sewage sludge has been dumped at sea in the Firth of Clyde, Scotland, for almost 90 yr. Prior to implementation of the Dumping at Sea Act (1974) it was dumped ca 2 km south of the Isle of Bute. Surveys at this site before 1974 showed the accumulation of organic material and metallic contaminants in the sediments. The present study describes the geographical distribution of trace metal concentrations in both surface and subsurface sediments in 1985. Trace metal concentrations in surface sediments were much lower than those reported while dumping was in progress. Marked elevations in trace metal concentrations were found w~t h depth in the sediments. A tentative trace metal budget for this disused disposal site is presented. About a quarter to a half of the input metals were retained in the sediment.

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