Launched in 2013, the EU-funded MIDAS (Managing impacts of deep-sea resources exploitation) project aimed to help the nascent deep-sea mining industry, regulators and civil society to understand the potential impacts of mining on deep-sea ecosystems. The consortium comprised a unique combination of scientists, social scientists, industry and legal experts, non-governmental organisations' and SMEs. 'The project focused mainly on the potential impacts associated with extraction of manganese nodules and seafloor massive sulphides (SMS), but also addressed environmental issues related to the exploitation of methane gas hydrates, and the potential of deep-sea muds in the North Atlantic as a source of rare earth elements' explains Professor Phillip Weaver, MIDAS project coordinator. Large volumes of fresh data have been collected via 30 research expeditions to MIDAS study areas. They included the mid-Atlantic Ridge, the Clarion-Clipperton Zone of the central Pacific, the Black Sea, and the Norwegian and Svalbard continental margins. Scientists examined the scale of the potential impacts of mining, for example, the size of the areas to be mined, the spread and influence of sediment plumes on these areas and the potential toxic nature of the material mined or thrown up into suspension. Understanding these impacts will enable researchers to comprehend the connections between populations and how the loss of biodiversity affects the working of ecosystems. They will also allow marine scientists to determine how resilient ecosystems are to disturbance and how rapidly they might recover. A key unknown to be addressed concerned the ability of ecosystems to recover once mining ceased in an area. MIDAS involved more than scientific research, according to Professor Weaver. He says: ′Our industry partners provided links to the commercial sector, so that we could gather opinion on likely mining scenarios, enabling MIDAS to draw up an environmental management framework that could facilitate responsible mining whilst taking account of environmental concerns. The timing of the project has been extremely opportune, coinciding with the International Seabed Authority's (ISA) development of a mining code for the exploitation of deep-sea minerals.’ A key discovery, researchers found no straightforward correlation between temperature and pressure changes with increasing water depth in relation to potential toxicity of chemicals that could be generated by some forms of deep-sea mining. This means that a large amount of new work will need to be carried out in this area since results from shallow water areas cannot be applied. Work on sediment-laden plumes showed that they can have major impacts on ecosystems for tens of kilometres away from the mined sites. This is one area that will require an investment in technology to limit the generation of plumes during mining and in legislation to make sure all contractors adhere to best practice. ′We are already using MIDAS results to help inform the development of regulations to control the nascent mining industry,’ Professor Weaver explains. ‘These regulations are being developed right now by the ISA. We have also brought our concerns about plumes to the attention of those who are developing new equipment in Europe, so that solutions can be sought to reduce this impact. Furthermore, our work on toxicology points the way to new research that is needed before mining can be approved for sulphide minerals.’ Thus, MIDAS has made an important contribution by identifying the potential scale and impacts of deep-sea exploitation and is already feeding that information through to policymaking bodies.
Deep-sea mining, MIDAS, sea floor massive sulphides, rare earth elements, regulation