A new report by Finnish scientists Laura Raikkonen and Elina A. Virtanen argues that, despite claims that shallow-water mining is a sustainable way to meet increasing demand for metals, environmental impacts can be high, while adequate protective legislation is still not in place.
The scarcity of certain minerals in terrestrial sources as well as the high high costs of deep-sea mining have been driving a change of focus towards shallow-water mining (mining in waters up to 200m deep), as some seabed deposits can have high concentrations of metals.
However, according to the article published by the journal Trends in Ecology and Evolution, the mining process in coastal areas, may have significant and negative impacts on the ecology of the continental shelves. Shallow water mining, the authors argue, exerts additional pressures on vulnerable coastal ecosystems which are already affected by the cumulative impacts of human activities and the effects of climate change.
The shallow water mining process, which consists of dredging the seafloor and sifting through up to 2.500 m³ of sediment per hour, may end up changing the ecological equilibrium of the sea floor.
“Mineral extraction removes the sediment, resident sea floor organisms, and ultimately the habitat, potentially resulting in local extinctions and changes in species composition.” Raikkonen and Virtanen state in the study. “In addition to altering seabed morphology, mineral extraction results in degradation of water quality through sediment plumes that increase water turbidity and smother organisms. There is also potential release of harmful substances from the sediment and disturbance to marine organisms via noise, light, and vibration from the operations.”
The article calls for a moratorium on these mining practices until these impacts are properly assessed and claims that shallow-water mining, due to its impacts, is in stark contrast with UN’s Sustainable Development Goals as it may have an impact on ocean life from which it may take decades to recover.