Sea-level rise in northern Australia's Kakadu National Park

a survey of floodplain eukaryotes

Sarah Stephenson, Tiffanie M. Nelson, Claire Streten, Karen S. Gibb, David Williams, Paul Greenfield, Anthony A. Chariton

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2 Citations (Scopus)

Abstract

Forecasted climate-change models predict that much of northern Australia's coastal habitats will be in retreat because of saltwater intrusion (SWI) from sea-level rise. A region of primary concern is the nutrient-rich and biodiverse floodplains of world heritage-listed Kakadu National Park (KNP). To understand the implications of SWI, we need fundamental baseline information for floodplain biota from the South Alligator River, KNP, northern Australia, and informative data on how increased and prolonged exposure to salt is likely to shape the eukaryotic community. To assist in addressing these key knowledge gaps, we used amplicon sequencing to examine the composition of eukaryotic soil communities from the South Alligator River floodplain, an ecologically important area at the 'coalface' of sea-level rise. Samples were obtained from three river zones and three floodplain morphologies, capturing a wide range of habitats and episodic exposures to both saltwater and freshwater. We found that both the floodplain morphology and positioning along the river significantly influenced eukaryotic composition. However, the influence of these variables varied greatly among the floodplain morphologies, with correlative evidence suggesting that both salinity and pH played a dominant role in shaping communities within lower parts of the floodplain, with this being particularly evident in those regions subjected to major tidal influence (estuarine funnel and sinuous, and cuspate).

Original languageEnglish
Pages (from-to)1134-1145
Number of pages12
JournalMarine and Freshwater Research
Volume69
Issue number7
DOIs
Publication statusPublished - 2018

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Keywords

  • climate change
  • flood morphology
  • metabarcoding
  • river zone
  • saltwater

Cite this

Stephenson, S., Nelson, T. M., Streten, C., Gibb, K. S., Williams, D., Greenfield, P., & Chariton, A. A. (2018). Sea-level rise in northern Australia's Kakadu National Park: a survey of floodplain eukaryotes. Marine and Freshwater Research, 69(7), 1134-1145. https://doi.org/10.1071/MF18067