Seabed mining has been proposed as a sustainable option whose environmental impact and costs would be smaller than that of traditional mining.
“The metal concentration of marine minerals is also often high, which is why the mining industry is now looking to the sea,” says Postdoctoral Researcher Laura Kaikkonen, lead author of the study from the Faculty of Biological and Environmental Sciences, University of Helsinki.
Marine areas at the core of mineral exploitation
The growing demand for nickel, cobalt and other battery metals in particular has increased interest in minerals found in the seabed. The latest indication of interest in mining in shallow marine areas is the application submitted by a Swedish mining company to mine ferromanganese concretions in the Gulf of Bothnia. Even though tin and diamonds, among other resources, have previously been mined in the territorial waters of other countries, mining metallic ore is an industrial field new to the Baltic Sea.
While the potential for utilising deep-sea minerals has long been recognised, their commercialisation has been limited by concerns about the effects of mining on sensitive deep-sea ecosystems.
“Abyssal species are still poorly known, with new species unknown to science constantly encountered,” says Postdoctoral Researcher Elina Virtanen, second author of the study from the University of Helsinki’s Finnish Museum of Natural History.
Mining in deep sea areas is also considerably expensive, which is why the mining of minerals from shallow marine areas has been proposed as a more sustainable solution to the increasing demand for minerals.
“The technical solutions needed to extract minerals from shallow marine areas already exist, including suction dredging. In addition, this kind of mining is less expensive,” Kaikkonen notes.
Expanded national legislation is needed
Minerals and precious metals are found in all marine areas around the globe (Image 1). There are also an abundance of minerals in Finnish marine areas in the form of ferromanganese concretions, which Kaikkonen and Virtanen described in a previous study conducted in 2019. Due to the lack of extensive utilisation of minerals found in shallow marine areas, there is no national legislation for its regulation, which, in turn, is why the mining industry is turning its gaze to the sea.
Risks in mining shallow marine areas
The environmental impact of the mining industry in shallow marine areas is not yet known.
“The environmental effects are probably similar to those of operations where the seafloor is excavated, such as dredging. It can take decades for the ecosystems to recover,” says Kaikkonen.
The ecosystems of shallow marine areas are in a weakened state to begin with, as human activity is concentrated in coastal areas. Mineral mining alters habitats as well as causes local biodiversity loss and changes in species communities. The indirect effects of mining, such as the spread of swirling seabed material and harmful substances released from the seafloor and the clouding of water, contribute to impairing the state of the marine environment.
“The possible environmental effects are in conflict with the latest conservation and sustainability goals,” says Virtanen. The EU and the UN have an ambitious goal of protecting 30% of all marine areas, and EU directives include items on achieving a good status for marine areas.
“The precautionary principle should be applied to mining in shallow marine areas, and operations should not be permitted until their risks have been mapped,” Kaikkonen says.“The ecological significance of minerals remains unclear, but, for example, ferromanganese concretions can serve as habitats for species.”
According to the researchers, discontinuing mining operations in shallow marine areas can be challenging if they are initiated before the relevant legislation is drafted and enacted.
Shallow-water mining undermines global sustainability goals
Laura Kaikkonen, Elina A. Virtanen Open Access, Published: September 13, 2022