Bringing the Ocean to Society
16 Nov 2018
New numerical models available to predict the impacts of Deep Sea Mining
Portuguese researchers develop tools to better understand what may change if DSM ever takes place in the Atlantic.

The deep sea was the focus of various EurOcean activities in 2018. In March we organised a World Café workshop in the Azores about deep sea mining, which was part of the H2020 MARINA project. That first event was followed by a Structured Democatric Dialogue workshop in Lisbon in May, also part of that same project. In October we went back to the Azores to discuss the role that deep sea research can have in terms of knowledge transfer and support to decision-making processes. We will continue to raise awareness and support a positive discussion on such hot topic. 

At a time when the seabed exploration is being heralded as the next big bet for the mining industry, researchers at the Interdisciplinary Center for Marine and Environmental Research (CIIMAR) have developed numerical models that allow predicting scenarios of sediment dispersal resulting from deep sea mining activities and anticipate its possible consequences on ecosystems. The study, developed under the CORAL - Sustainable Exploration of the Oceans project (supported by the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund), in a partnership between CIIMAR and INESC-Tec, was published in the prestigious international journal Science of the Total Environment.

Deep sea mining presents itself as an possibility for obtaining metals and minerals for various industries. The seabed of the Portuguese Exclusive Economic Zone (EEZ), particularly in the areas near hydrothermal vents, presents massive sulphides rich in copper or nickel among other elements, materials with high economic interest. However, most of these resources are located in areas close to unique ecosystems of great ecological value, which may be damaged due not only to their own extraction activities, but also to the emission and transport of sediments and associated noise or light.

The CIIMAR team involved in CORAL underlines that before beginning to license mining activities in the deep sea, it is urgent to establish environmental and management guidelines that allow sustainable exploitation to minimize their impacts, and for this it is needed to develop tools to anticipate their effects.

CIIMAR's work responded to this problem by implementing a numerical tool to analyse scenarios of sediment dispersal associated with possible mining activities in areas near three important hydrothermal sources located in the Portuguese EEZ southwest of the Azores and classified by OSPAR as Marine Protected Areas since 2007. These numerical models allow to understand and represent the oceanic dynamics of these areas, and to predict the scenarios of dispersion of different sedimentary particles resulting from mining activities, depending on the depth, geomorphology and hydrodynamics of the sites.

Despite the great variability of the results due to the sediment type, zone morphology and depth of sediment release, the study now concludes that the particles associated to possible mining activities in the areas near the hydrothermal sources can remain in motion for a period varying between 14 and 40 days and can affect a large number of ecosystems within a radius of up to 190 km.

The numerical models therefore constitute fundamental tools to predict the possible impact of mining activities in the deep sea, to delimit ecosystem protection zones, to support the implementation of monitoring and risk assessment plans, and to design actions mitigation.

To access the new publication click here.