May 17, 2024

Scientists Discover Hidden Threat to the Great Barrier Reef

Diagram revealing groundwater sources on Great Barrier Reef. Credit: Douglas Tait
Study discovers nearly twice the amount of nitrogen is going into the Reef from groundwater compared to river waters.
Scientists utilizing natural tracers off Queenslands coast have discovered the source of previously unquantified nitrogen and phosphorous having a profound environmental effect on the Great Barrier Reef.
The findings, published today in Environmental Science and Technology, suggest present efforts to preserve and bring back the health of the Reef might need a new viewpoint.

Southern Cross Universitys Dr. Douglas Tait leads the ground-breaking research study, Submarine groundwater discharge exceeds river inputs as a source of nutrients to the Great Barrier Reef.
Submarine groundwater discharge is any water released to the ocean below the waterline from numerous sources, including underground aquifers and the seafloor.
Composite showing beautiful coral together with eutropohied coral on Great Barrier Reef. Credit: Ashly McMahon
Research Implications and findings
The research study group, which likewise includes CSIRO, AIMS, and Gothenburg University (Sweden), gathered information from offshore transects, rivers, and coastal bores in an area from south of Rockhampton to north of Cairns. The use of radium isotopes permitted the researchers to track just how much nutrient is transferred from the land and rack sediments through unnoticeable groundwater circulations.
Southern Cross Professor Damien Maher stated the groups work revealed that groundwater discharge was 10-15 times higher than river inputs, something previously unaccounted for.
” Groundwater discharge accounted for approximately one-third of brand-new nitrogen and two-thirds of phosphorous inputs, showing that almost two times the quantity of nitrogen goes into the Reef from groundwater compared to river waters,” Professor Maher stated.
Teacher Maher added that the lions share of efforts to alleviate the impact of nutrients on the Reef were focused on outflow from river systems.
Eutropohied coral on Great Barrier Reef. Credit: Ashly McMahon
Prospective Environmental Impact and Recommendations
Lead author Dr. Douglas Tait said: “Nutrients are vital to support the incredible biodiversity of the Great Barrier Reef.”
” However, an excess of nutrients can lead to destructive issues such as hazardous algal blossoms, crown-of-thorns starfish break outs, and fish illness, which have been on the increase in the Reef over the previous couple of years.
” Our study underscores the need for a tactical shift in management techniques targeted at safeguarding the Great Barrier Reef from the results of excess nutrients.”
Dr. Tait said unlike river outflow, nutrients in groundwater could be kept for years underground before being discharged into seaside waters, suggesting research study and methods to protect the Reef required to be long-lasting.
” This research study sheds brand-new light on the complex nutrient characteristics within the Great Barrier Reef,” Dr. Tait stated.
” Our understanding and ability to handle the sources of nutrients is essential in protecting the Reef for generations to come.”
Reference: “Submarine Groundwater Discharge Exceeds River Inputs as a Source of Nutrients to the Great Barrier Reef” by Douglas R. Tait, Isaac R. Santos, Sèbastien Lamontagne, James Z. Sippo, Ashley McMahon, Luke C. Jeffrey and Damien T. Maher, 8 October 2023, Environmental Science & & Technology.DOI: 10.1021/ acs.est.3 c03725.
The task was supported with funding from the Australian Research Council, the Herman Slade Foundation, and the Great Barrier Reef Foundation.