Schmidt et al., 2004, focuses on four islands in the Great Barrier Reef: Heron Island, One Tree Island, Raine Island; and Low Isles.  The research was conducted to determine:

1. Which nitrogen (N) sources are utilised by plants in cay communities;
2. how N is distributed within the cay, and
3. whether seabird-derived N moves from cay to the surrounding low-N marine environment.

Key findings from the study on the islands are noted below:

• Coral cays with high densities of seabirds are areas of extreme nitrogen (N) enrichment with deposition rates of up to 1000 kg N ha-1 y-1. 
• Waters from the aquifer under the Heron reef had high NO^₃- concentrations (0.23 - 1.76 mM NO^₃-, average 1.0 +/- 0.44 s.d.) and 2-orders of magnitude lower NH₄⁺ concentrations (0.001 - 0.041 mM NH₄⁺, average 0.011 =/- 0.011 s.d.). 
• There were no consistent differences in N concentrations of waters collected from wells situated in the forest or at the beach. 
  
• Seabirds concentrate N of marine origin via guano deposition on the cay, some N volatilises as NH₃ back into the atmosphere, a substantial proportion of N leaches, mostly as NO^₃-, into the surficial aquifer, and aquifer waters exchange with marine waters at sites of the outer reef slope. 

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Citation and/or URL

Schmidt, S., Dennison, W.C., Moss, G.J. & Stewart, G.R. 2004, Nitrogen ecophysiology of Heron Island, a subtropical coral cay of the Great Barrier Reef, Australia, Functional Plant Biology, 31: 517-528. © CSIRO 2004. CSIRO Publishing, Collingwood Australia - http://www.publish.csiro.au/nid/102/paper/FP04024.htm

Spatial Coverage

 Heron Island, One Tree Island, Rains Island and Low Isles

Temporal Coverage

Update Frequency

Other Information

 None