Australia: A new study has found that pollution, particularly nitrogen and phosphorus, is reaching the Great Barrier Reef through underground water sources in significant quantities. The latest findings could have implications for policymakers focused on cutting pollution from river catchments.
Governments and agencies have placed significant emphasis on managing pollution that flows from farms into the reef. According to scientists, enhancing water quality is crucial for increasing the chances of coral recovery following bleaching events caused by global warming.
The decade-long research, published in the journal Environmental Science & Technology, was conducted by scientists at Southern Cross University, the Australian Institute of Marine Science, and CSIRO. Researchers took water samples and analysed them for radium isotopes that act as markers for pollution.
Dr. Douglas Tait, an expert on the chemistry of coastal waters at Southern Cross University and the lead author of the research, noted that the pollutants could take decades to move from farms to underground aquifers before emerging from springs at the coastline and from underwater springs, known as wonky holes, in the reef lagoon itself.
Dr. Tait added that “it was possible that this could just be the start of the front [of pollution] that is coming through, or it could be the tail-end. We could have a significant problem realised in the coming decades.”
Prof. Damien Maher, a co-author of the research also from Southern Cross University, commented that “groundwater discharge accounted for approximately one-third of new nitrogen and two-thirds of phosphorus inputs, indicating that nearly twice the amount of nitrogen enters the reef from groundwater compared to river waters.”
Mr. Tait remarked that the study “underscores the need for a strategic shift in management approaches to reduce the harm from pollutants.”
According to the researcher, there were a range of likely pathways that the pollution could take through groundwater, from moving through cracks and fissures in rocks below the top soil to dripping through porous rocks.
“We’re going to need to have a discussion about how these nutrients are managed. We need a much better understanding of this process so that we can manage it in the future,” Mr. Tait added.
MOST READ | UNESCO to launch virtual museum of stolen artefacts
