Study

Response of estuarine wetlands to reinstatement of tidal flows

  • Published source details Howe A.J., Rodríguez J.F., Spencer J., MacFarlane G.R. & Saintilan N. (2010) Response of estuarine wetlands to reinstatement of tidal flows. Marine and Freshwater Research, 61, 702.

Actions

This study is summarised as evidence for the following.

Action Category

Facilitate tidal exchange to restore/create brackish/saline swamps from other land uses

Action Link
Marsh and Swamp Conservation

Facilitate tidal exchange to restore/create brackish/salt marshes from other land uses

Action Link
Marsh and Swamp Conservation
  1. Facilitate tidal exchange to restore/create brackish/saline swamps from other land uses

    A before-and-after study in 1993–2004 in an estuary in New South Wales, Australia (Howe et al. 2010) reported that after removing culverts to improve tidal exchange to an island, the area of mangrove vegetation increased. Mangrove forests covered 1 ha of the study area two years before culvert removal, 5 ha three years after culvert removal, and 12 ha nine years after culvert removal. Mangroves benefitted from the expansion of intertidal habitat, which provided a suitable physical environment. Other habitats present in the study site included salt marsh vegetation (before: 44 ha; after nine years: 53 ha), tidal pools/mudflats (before: 33 ha; after nine years: 32 ha) and upland pasture (before: 42 ha; after nine years: 22 ha). Methods: The study focused on an island in the Hunter River Estuary, which had been partially drained for agriculture. In 1995, two 0.5-m-diameter culverts in a tidal inlet were removed, restoring full tidal exchange to approximately one fifth of the island. Tidal exchange was slightly improved across the rest of the marsh, where culverts remained in place. Habitats were mapped from aerial photographs taken in 1993, 1998 and 2004.

    (Summarised by: Nigel Taylor)

  2. Facilitate tidal exchange to restore/create brackish/salt marshes from other land uses

    A before-and-after study in 1993–2004 in an estuary in New South Wales, Australia (Howe et al. 2010) reported that after removing culverts to improve tidal exchange to an island, the area of salt marsh vegetation increased. Salt marsh vegetation covered 44 ha of the study area two years before culvert removal, 52 ha three years after culvert removal, and 53 ha nine years after culvert removal. Other habitats present in the study site included mangrove forests (before: 1 ha; after nine years: 12 ha), tidal pools/mudflats (before: 33 ha; after nine years: 32 ha) and upland pasture (before: 42 ha; after nine years: 22 ha). Methods: The study focused on an island in the Hunter River Estuary, which had been partially drained for agriculture. In 1995, two 0.5-m diameter culverts in a tidal inlet were removed, restoring full tidal exchange to approximately one fifth of the island. Tidal exchange was slightly improved across the rest of the marsh, where culverts remained in place. Habitats were mapped from aerial photographs taken in 1993, 1998 and 2004.

    (Summarised by: Nigel Taylor)

Output references
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