Standard Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Walk beside me – restoring coastal wetlands for a range of value outcomes (#533)

Nathan Waltham 1 , Jim Wallace 1 , Jacob Cassaday 2 , Paula Cartwright 1
  1. James Cook University, Douglas, QLD, Australia
  2. Mungalla Aboriginal Development Corporation, Ingham, QLD, Australia

Many wetlands along the coastal floodplains of north Queensland have been heavily modified due to the construction of earth bunds to stop seawater inundation. This was done to create ponded pasture for grazing or land suitable for growing sugarcane, when additional drainage was added. However, over time the ponded pastures were often subject to extensive freshwater weed infestations and the ecological conditions became highly degraded. More recently there has been a move towards restoring the more nature-based freshwater – seawater cycling in some wetlands by breaching the earth bunds. This presentation shows an example where Nwagai Traditional Owners have been working with scientists to understand the natural dynamics of a coastal wetland at Mungalla station in north Queensland where an earth bund was constructed in the early 1900’s to exclude seawater. We describe the main changes in water conditions that affected the vegetation and aquatic biota before and after its earth bund was breached in 2013.  This unique 11 year study highlights the more natural dynamic nature of the wetland and the multi-year time scales of its cycling between freshwater and saline conditions.  Our understanding of this wetland would not have been possible with walking along side Nywaigi Traditional Owners.