The Assessment will be undertaken in conjunction with the local community, Norfolk Island Regional Council and Parks Australia.
Why is CSIRO undertaking a water quality assessment on Norfolk?
Concern regarding the water quality of Norfolk Island’s inshore marine water, fresh surface water and groundwater and the condition of coral reefs in Emily Bay and Slaughter Bay has spanned several decades. Emily Bay and Slaughter Bay lie on the southern side of Norfolk Island adjacent to the world heritage listed Kingston and Arthurs Vale Historic Area (KAVHA) on the Kingston lowlands. These bays, along with neighbouring Cemetery Bay, are popular recreational and tourist attractions. The Norfolk Island Marine Park is part of the Temperate East Marine Park Network managed by Parks Australia.
In 2021, a lagoonal reef ecosystem health assessment commissioned by Parks Australia reported declining coral health in Emily and Slaughter bays. Discharge of poor water quality including high nutrient concentrations was thought to contribute to reef health decline. However, there was insufficient water quality monitoring data to access any change in marine water quality or to support management decisions on how to improve protection of marine water quality. This Assessment seeks to increase the knowledge of water quality and potential risks to marine water quality.
In addition, the water quality assessment will continue to assess acid sulfate soils to expand on the understanding gained in the Norfolk Island Water Resource Assessment. Drying or disturbance of acid sulfate soils can negatively impact on soil and water resources, including the sensitive marine environment within Emily and Slaughter bays, human and animal health and infrastructure, including heritage structures in KAVHA.
The information provided by the Assessment can be used to help inform the Norfolk Island community, and the Norfolk Island Water Quality Working Group, which includes representatives from the Department of Infrastructure, Transport, Regional Development, Communications and the Arts, Parks Australia and the Norfolk Island Regional Council, to make decisions on how to improve water quality management and specifically to improve protection of the marine environment.
The Norfolk Island Water Quality Assessment is distinct from the Norfolk Island Water Resource Assessment. The water quality Assessment relies on information provided by the Norfolk Island Water Resource Assessment on surface water and groundwater systems and their interactions. However, the water quality Assessment requires new information on marine water quality and on groundwater and surface water in KAVHA. The KAVHA area was not assessed in the water resource Assessment due to the presence of a localised calcarenite carbonate aquifer which is not considered to be a significant water resource for the island and the risk of saline intrusion.
Importantly CSIRO will provide scientific input but not be advocating for a particular approach.
As part of this Assessment CSIRO will undertake a program of data collection and field measurements. These will include measurements of marine, surface and ground water quality, monitoring of submarine groundwater and surface water discharge, and soil characterisation. Marine water quality monitoring locations will be informed by the lagoonal reef ecosystem health investigations. As the focus of the Assessment is water quality that may be impacting on reef health in Emily Bay and Slaughter Bay, field measurements will be concentrated in KAVHA and the Watermill Creek and Town Creek surface water catchment. Anecdotal information, such as observation of groundwater discharge into the lagoonal bays, held by members of the community will be vital to the success of the Assessment.
Specifically the project seeks to:
- implement a water quality monitoring program on Norfolk Island
- enhance the capacity of the community and Council to manage their water resources and inform the Australian Government about investment decisions related to water quality management
- develop marine water quality targets and a water quality program for environmental protection specific to Norfolk Island
- assess the occurrence of acid sulfate soils across Norfolk, as these soils can have significant impacts on the environment animal and human health and infrastructure.