A science consortium led by CSIRO, Australia’s national science agency, has developed the first environmental management and monitoring frameworks to protect deep sea ecosystems, should the International Seabed Authority (ISA) permit deep-sea mining.
The project was commissioned by The Metals Company Australia Pty Ltd (TMC) and brought together scientists from CSIRO, Griffith University, Museums Victoria, the University of the Sunshine Coast, and Earth Sciences New Zealand (formerly NIWA and GNS Science).
The scientists’ role was to provide objective and independent science-based evidence so that, if deep-sea mining does proceed, decisions can be guided by robust and transparent environmental assessments.
Importantly, this research is not an Environment Impact Statement or an Environmental Management and Monitoring Plan, both of which are requirements of mining proponents under international regulations.
The research focused on the Clarion Clipperton Zone (CCZ) in the Pacific Ocean – a region being considered for potential mining of polymetallic nodules containing critical minerals like cobalt and nickel, which are viewed as essential for renewable energy technologies.
The scientists analysed data from test mining activities that were carried out in the CCZ by TMC under approval by the ISA.
The integrated ecosystem assessment and ecosystem-based management framework from this research offer important insights into how we can assess impacts and risks to ecosystems in the deep sea that may be potentially exposed to mining.
To address uncertainties and data scarcity in the deep sea, scientists used an ecosystem-based management (EBM) framework that helps assess and manage the environmental risks of deep-sea mining.
This eight-step process includes stakeholder engagement, risk assessment, and ongoing monitoring, and is designed to be adapted as new data becomes available.
Dr Piers Dunstan, Senior Principal Research Scientist at CSIRO, said the project sets a new benchmark for environmental assessment in one of Earth’s most fragile and unknown ecosystems.
“This project helps ensure that if deep-sea mining were to go ahead, there is a clear approach to understand potential risks and impacts to marine life and ecosystems,” Dr Dunstan said.
“There will be impacts at deep-sea mining sites, and our research shows the speed and scale of potential recovery differs across functional groups of species.
“The research also provides guidance for the regulator about how serious harm can be identified and how this can be operationally implemented.
“Continued monitoring of the effects of any mining on marine ecosystems would be crucial to validate these findings.”
Key outcomes of the project include:
- A clear definition of ‘serious harm’ using a traffic light system – green for minor impacts, orange for moderate, and red for major, irreversible damage. This would help regulators know when to act or halt mining operations.
- A full ecosystem model of the CCZ, linking surface waters to the seafloor, which predicts that mining impacts are likely to be localised to the seabed.
- A suite of environmental indicators to monitor changes in biodiversity and ecosystem health, tailored to plausible operational mining scenarios.
- A risk-based management process that assumes full ecosystem loss unless proven otherwise, ensuring a precautionary approach to mining.
- Quantitative estimation of impacts to pelagic ecosystems from metals and risk of impact to deep sea benthic ecosystems.
This research provides decision-makers with trusted, science-based tools to evaluate the environmental risks and viability of deep-sea mining.
It supports the work of the ISA and precautionary approaches to management of the seabed in international waters.
All reports and findings are publicly available.
Read an explainer on this project.
View the media briefing, hosted by the Australian Science Media Centre.
