Author(s): Alice Howe
Linked Author(s):
Keywords: Ecohydraulics; Estuarine wetlands; Migratory shorebirds; Coastal development; Management
Abstract: Coastal salt marsh provides important roost habitat for migratory shorebirds. In Australia, its distribution appears to be following a global trend of decline, as it is squeezed between landward encroachment of mangrove forest and urban/industrial development of foreshore land. Efforts to maintain and rehabilitate salt marsh are complicated by an incomplete understanding of the ecological and hydraulic processes that govern estuarine vegetation distribution. Our research is focused on the hydraulic and geomorphologic conditions required to sustain salt marsh in a rehabilitated wetland in the Hunter estuary, NSW. The effect of culvert removal on habitat availability for migratory shorebirds is examined through high resolution mapping of tidal inundation, topographic elevation and habitat distribution, and measurement of the flow field at discrete locations using acoustic Doppler velocimeters. This analysis has allowed development of habitat zonation curves for areas of attenuated and unattenuated tidal flow in the study area, which support the landward migration of mangroves following culvert removal. Characterisation of the hydraulic flow field has identified significant differences in velocity and turbulent kinetic energy that have wider implications for rates of sediment accretion in estuarine wetlands.
Year: 2005