Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Response of estuarine wetlands to reinstatement of tidal flows

Alice J. Howe A , José F. Rodríguez A D , Jennifer Spencer B , Geoff R. MacFarlane C and Neil Saintilan B

A School of Engineering, University of Newcastle, Callaghan, NSW 2308, Australia.

B NSW Department of Environment, Climate Change and Water, Sydney South, NSW 1232, Australia.

C School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.

D Corresponding author. Email:

Marine and Freshwater Research 61(6) 702-713
Submitted: 8 July 2009  Accepted: 15 December 2009   Published: 25 June 2010


The importance of estuarine wetlands to ecosystem services such as primary productivity and flood attenuation, as well as their function as habitat for threatened species has prompted efforts to restore tidal flows to degraded wetlands. We tracked the response of estuarine vegetation to tidal-flow reinstatement over 12 years (1995–2007) in a wetland of the Hunter estuary, Australia. This site provides important habitat for migratory shorebird species, which favour shallow tidal pools and saltmarsh over mangrove forest. Increased tidal flows following culvert removal reduced shorebird roost habitat by 17% because of mangrove encroachment on saltmarsh and shallow tidal pools. Saltmarsh occurred in areas with a spring tidal range <0.3 m, hydroperiod <1.0 and elevation >0.4 above the Australian height datum (mAHD), whereas mangrove occupied areas with spring tidal range >0.3 m, hydroperiod <0.45 and elevation <0.4 mAHD. By using these parameters, it is possible to exclude mangrove from saltmarsh areas and to establish saltmarsh at lower elevations in the tidal frame than would occur under natural conditions, effectively expanding saltmarsh area. These measures can be useful where landward migration of estuarine communities is restricted by infrastructure; however, they should not be considered a substitute for conservation of remnant saltmarsh or establishment of landward buffer zones.

Additional keywords: Hunter estuary, mangrove, migratory shorebirds, saltmarsh, south-eastern Australia, wetland rehabilitation.


Adam P. (1990). ‘Saltmarsh Ecology.’ (Cambridge University Press: Cambridge, UK.)

Adam P.2002Saltmarshes in a time of change.Environmental Conservation293961doi:10.1017/S0376892902000048

Bockelmann A.-C.Bakker J. P.Neuhaus R.Lage J.2002The relation between vegetation zonation, elevation and inundation frequency in a Wadden Sea salt marsh.Aquatic Botany73211221doi:10.1016/S0304-3770(02)00022-0

Boorman L. A.1999Salt marshes – present functioning and future change.Mangroves and Salt Marshes3227241doi:10.1023/A:1009998812838

Breitfuss M. J.Connolly R. M.Dale P. E. R.2003Mangrove distribution and mosquito control: transport of Avicennia marina propagules by mosquito-control runnels in southeast Queensland saltmarshes.Estuarine, Coastal and Shelf Science56573579doi:10.1016/S0272-7714(02)00207-X

Burdick D. M.Dionne M.Boumans R. M. J.Short F. T.1996Ecological responses to tidal restorations of two northern New England salt marshes.Wetlands Ecology and Management4129144doi:10.1007/BF01876233

Clarke K. R., and Gorley R. N. (2001). ‘PRIMER v5: Users Manual/Tutorial.’ (PRIMER-E Ltd: Plymouth, UK.)

Clarke L. D.Hannon N. J.1967The mangrove swamp and salt marsh communities of the Sydney district: I. Vegetation, soils and climate.Journal of Ecology55753771doi:10.2307/2258423

Clarke L. D.Hannon N. J.1971The mangrove swamp and salt marsh communities of the Sydney district. IV. The significance of species interaction.Journal of Ecology59535553doi:10.2307/2258330

Clarke P. J.Myerscough P. J.1993The intertidal distribution of the grey mangrove (Avicennia marina) in southeastern Australia: the effects of physical conditions, interspecific competition, and predation on propagule establishment and survival.Australian Journal of Ecology18307315

Clarke K. R., and Warwick R. M. (2001). ‘Change in Marine Communities: An Approach to Statistical Analysis and Interpretation.’ (PRIMER-E Ltd: Plymouth, UK.)

Department of the Environment and Heritage (2005). ‘Background Paper to the Wildlife Conservation Plan for Migratory Shorebirds.’ (Australian Government: Canberra.)

Ellison A. M.2000Mangrove restoration: do we know enough?Restoration Ecology8219229

Gedan K. B.Silliman B. R.Bertness M. D.2009Centuries of human-driven change in salt marsh ecosystems.Annual Review of Marine Science1117141doi:10.1146/ANNUREV.MARINE.010908.163930

Geoscience Australia (2008). ‘AUSGeoid98.’ Available at [accessed 30 June 2009].

Gosbell K.Clemens R.2006Population monitoring in Australia: some insights after 25 years.Stilt50162175

Howe A. J.Rodríguez J. R.Saco P. M.2009Surface evolution and carbon sequestration in disturbed and undisturbed wetland soils of the Hunter estuary, southeast Australia.Estuarine, Coastal and Shelf Science847583

Kingsford R. T., Ferster Levy R., Geering D., Davis S. T., and Davis J. S. E. (1998). ‘Rehabilitating Estuarine Habitat on Kooragang Island for Waterbirds, Including Migratory Wading Birds (May 1994 – May 1997).’ (NSW National Parks and Wildlife Service: Hurstville, NSW.)

Kuhn N. L.Mendelssohn I. A.Reed D. J.1999Altered hydrology effects on Louisiana salt marsh function.Wetlands19617626doi:10.1007/BF03161699

Lane B. (1987). ‘Shorebirds in Australia.’ (Nelson Publishing: Melbourne.)

Lear R., and Turner T. (1977). ‘Mangroves of Australia.’ (University of Queensland Press: St Lucia, Qld.)

MacDonald T. (2001). Investigating the estuarine wetlands of the lower Hunter River: rehabilitation potential of tidal reinstatement following degradation caused by tidal restriction. Ph.D. Thesis, University of Newcastle, NSW.

Marani M.Silvestri S.Belluco E.Ursino N.Comerlati A.Tosatto O.Putti M.2006Spatial organisation and ecohydrological interactions in oxygen-limited vegetation ecosystems.Water Resources Research42W06D06doi:10.1029/2005WR004582

Millennium Ecosystem Assessment (2005). ‘Ecosystems and Human Wellbeing: Wetlands and Water Synthesis.’ (Word Resources Institute: Washington, DC.)

Mitchell M. L.Adam P.1989The relationship between mangrove and saltmarsh communities in the Sydney Region.Wetlands (Australia)83746

Montalto F. A.Steenhuis T. S.2004The link between hydrology and restoration of tidal marshes in the New York/New Jersey estuary.Wetlands24414425

Montalto F. A.Steenhuis T. S.Parlange J.-Y.2006The hydrology of Piermont Marsh, a reference for tidal marsh restoration in the Hudson River estuary, New York.Journal of Hydrology316108128doi:10.1016/J.JHYDROL.2005.03.043

Mueller-Dombois D., and Ellenberg H. (1974). ‘Aims and Methods of Vegetation Ecology.’ (John Wiley & Sons: New York.)

Pethick J.1993Shoreline adjustments and coastal management: physical and biological processes under accelerated sea-level rise.Geographical Journal159162168doi:10.2307/3451406

Reed D. J. de Luca N.Foote L.1997Effect of hydrologic management on marsh surface sediment deposition in coastal Louisiana.Estuaries20301311doi:10.2307/1352345

Saintilan N.1997Mangroves as successional stages on the Hawkesbury River.Wetlands1699107

Saintilan N., and Rogers K. (2002). The declining saltmarsh resource. In ‘Coast to Coast 2002 – Australia’s National Coastal Conference, Tweed Heads, 4–8 November 2002’. (Eds B. Thom and P. Coughlan.) pp. 410–413. (CRC for Coastal Zone, Estuary and Waterway Management: Indooroopilly, Qld.)

Saintilan N.Williams R. J.1999Mangrove transgression into saltmarsh environments in south-east Australia.Global Ecology and Biogeography8117124

Saintilan N., Rogers K., and Howe A. (2009a). Geomorphology and habitat dynamics. In ‘Australian Saltmarsh Ecology’. (Ed. N. Saintilan.) pp. 53–74. (CSIRO Publishing: Melbourne.)

Saintilan N., Rogers K., and McKee K. (2009b). Salt marsh – mangrove interactions in Australasia and the Americas In ‘Coastal Wetlands: An Integrated Ecosystem Approach’. (Eds G. M. E. Perillo, E. Wolanski, D. R. Cahoon and M. M. Brinson.) pp. 855–884. (Elsevier: Amsterdam.)

Silvestri S.Defina A.Marani M.2005Tidal regime, salinity and salt marsh plant zonation.Estuarine, Coastal and Shelf Science62119130doi:10.1016/J.ECSS.2004.08.010

Simenstad C.Reed D.Ford M.2006When is restoration not? Incorporating landscape-scale processes to restore self-sustaining ecosystems in coastal wetland restoration.Ecological Engineering262739doi:10.1016/J.ECOLENG.2005.09.007

Smith R. T., and Atkinson K. (1975). ‘Techniques in Pedology: A Handbook for Environmental and Resource Studies.’ (Paul Elek (Scientific Books) Ltd: London.)

Spencer J. A. (2009). Migratory shorebird ecology in the Hunter estuary, south-eastern Australia. Ph.D. Thesis, Australian Catholic University, Sydney.

Streever W. J.Genders A. J.1997Effect of improved tidal flushing and competitive interactions at the boundary between salt marsh and pasture.Estuaries20807818doi:10.2307/1352253

Thelen B. A.Thiet R. K.2009Molluscan community recovery following partial tidal restoration of a New England estuary, USA.Restoration Ecology17695703doi:10.1111/J.1526-100X.2008.00397.X

Tomlinson P. B. (1986). ‘The Botany of Mangroves.’ (Cambridge University Press: Cambridge, UK.)

Torres R., Goñi M. A., Voulgaris G., Lovell C. R., and Morris J. T. (2004). Effects of low tide rainfall on intertidal zone material cycling. In ‘Ecogeomorphology of Tidal Marshes’. (Eds S. Fagherazzi, A. Marani and L. K. Blum.) pp. 93–114. (American Geophysical Union: Washington, DC.)

Ursino N.Silvestri S.Marani M.2004Subsurface flow and vegetation patterns in tidal environments.Water Resources Research40W05115doi:10.1029/2003WR002702

Wang C.Menenti M.Stoll M.Feola A.Belluco E.Marani M.2009Separation of ground and low vegetation signatures in LiDAR measurements of salt-marsh environments.IEEE Transactions on Geoscience and Remote Sensing4720142023doi:10.1109/TGRS.2008.2010490

Warren R. S.Fell P. E.Rozsa R.Brawley A. H.Orsted A. C.Olson E. T.Swamy V.Niering W. A.2002Salt marsh restoration in Connecticut: 20 years of science and management.Restoration Ecology10497513doi:10.1046/J.1526-100X.2002.01031.X

Weinstein M. P.Teal J. M.Balletto J. H.Strait K. A.2001Restoration principles emerging from one of the world’s largest tidal marsh restoration projects.Wetlands Ecology and Management9387407doi:10.1023/A:1012058713910

West R. J.1995Rehabilitation of seagrass and mangrove sites – successes and failures in NSW.Wetlands141319

Williams R. J.Watford F. A.1997Identification of structures restricting tidal flow in New South Wales, Australia.Wetlands Ecology and Management58797

Williams R. J., Hannan J., and Balachov V. (1995). Kooragang Wetland Rehabilitation Project: fish, decapod crustaceans and their habitats. First Interim Report, Summer 1993–94. NSW Fisheries, Sydney.

Zedler J. B.Callaway J. C.2000Evaluating the progress of engineered tidal wetlands.Ecological Engineering15211225doi:10.1016/S0925-8574(00)00077-X

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