Geological, physical, chemical and biological studies relating to dynamics, circulation, sediment transport and deposition in Western Port, Victoria, Australia have identified potential problems in the marine and coastal zones. The knowledge embodied in these studies and their conclusions have been incorporated into a series of recommendations forming the basis for Interim Advice and Guidelines to government for management of the bay and its catchment. Some major conclusions were: (1) six coastal areas were identified for conservation; (2) some industrial development, housing, and recreational facilities could be extended with appropriate environmental safeguards; (3) considerable care may be needed in the discharges of phosphorus to protect the bay's potentially susceptible ecosystems; (4) additional port facilities that require dredging and disposal could cause significant environmental damage and proposed projects should be carefully and individually assessed. The Study of Western Port is continuing into Phase II as the Westernport Regional Environmental Study. The regional study also is linked with studies of the catchments of Port Phillip and the Gippsland Lakes. Phase II of the Westernport Study is directed towards the continued development and implementation of management recommendations and particularly towards specific management decisions based on assessment of environmental impact of industrial, recreational, and urban development proposals. © 1979.