Estuarine wetlands distribution along the Parramatta River, Sydney, 1788–1940 : implications for planning and conservation

This study examined a variety of written, cartographic and pictorial historical materials to document the extent and distribution of inter-tidal wetlands and riparian vegetation along the Parramatta River and its bays from 1788 (first settlement in Port Jackson) to c. 1940 (when documentation by aerial photographs commenced). Although data available do not permit detailed quantitative analysis, and no single source is definitive, in total they yield a more detailed picture has hitherto been available. These historical sources indicate that in the 19th century extensive mudflats and saltmarsh communities dominated the inter-tidal zone, with mangroves more limited to creek fringes and some patches in bays for much of the period. In the upper river from Subiaco Creek to Parramatta, there is no evidence for the presence of mangroves until the 1870s. Following settlement and increased sedimentation, inter-tidal mudflats expanded, mangroves colonised up river and out onto mudflats in bays in the latter part of the 19th century, followed by expansion into saltmarsh in the 20th century. This study demonstrates that some of the assumptions regarding the former extent of mangroves on which recent studies and foreshore plans are based are inappropriate. The historical data, combined with subsequent aerial photographic data, provides an enlarged database that needs to be taken into account in the formulation of conservation management plans and restoration strategies