The report describes a survey of the Fleet lagoon and Portland Harbour. Investigations in the sublittoral cover the sediments, salinity, temperature, the general environment and subtidal communities. Information up to 1984 on the Fleet is reviewed. A full species list is given. There is a most apparent contrast between the biological communities of the lagoonal basin and the link-channel zone. The former is dominated by eel grass and most previous work with the lagoon has focused here. The subtidal communities of the link-channel zone were examined at a series of eight stations.
