Marine Resources on the Extension of the Continental Shelf
The living and non-living resources of the seabed are increasingly seen as an alternative to the exploitation of such resources on land. As resource scarcity increases in continental areas and prospective and extractive technologies progress, the exploitation of mineral, energy (including methane hydrates) and genetic resources in the deep seabed is becoming increasingly feasible. Many of these resources are found on the continental shelves and their extension areas, making these areas of soil and subsoil new sources of wealth for coastal States.
The scientific exploration of the national seabed remains limited and poorly characterised. However, the data and knowledge gained over the years through scientific research campaigns and cruises dedicated to the purposes of the CSEP have allowed the vast potential of the different resources found on the continental shelf of Portugal to be identified.
Fig. 1 - Deep Sea Resources
With the CSEP, the reasons to consolidate existing data and evaluate new mineral resources only multiply. It is undeniable that mining is a risky undertaking and that a lack of knowledge of existing resources and strong international competition are constraints. Even so, the challenge and the opportunity cannot be ignored: concrete measures, relatively low in cost and simple to apply, would allow exploration projects and possible exploration to be pursued in the short term.
Mettalic Mineral Resources
Metallic mineral resources have been known to exist in the Portuguese EEZ for several decades. Known resources include polymetallic nodules, Co-rich Fe-Mn crusts and polymetallic sulphides. The extension of the Portuguese continental shelf will open doors for the discovery of new mineral deposits.
Polimettalic Sulphids (Cu, Zn, Ag and Au)
Recent scientific exploration of the seabed, which reached its heyday in the nineties, especially in the Azores region, has demonstrated the existence of metallic resources associated with hydrothermal fields. Various international oceanographic missions inside the EEZ and areas adjacent to the Mid-Atlantic Ridge have resulted in the discovery of five active hydrothermal fields – Menez Gwen, Lucky Strike and Saldanha, located inside the EEZ, and the Rainbow and Moytirra fields, located on the extended continental shelf. The exploitation of mineral resources at a depth of 1,500m, which until recently was mere science fiction, may be possible by the second decade of the twenty-first century.
The existence of unique ecosystems in the active hydrothermal fields poses new and formidable challenges to the sustainable exploitation of the mineral deposits formed there. Perhaps the wisest investment will consist of developing new tools and technology to identify and explore the inactive hydrothermal fields where these ecosystems are not present.
Fig. 2 - Chimney of the Lucky Strike hydrothermal vent
Fe-Mn Nodules and Crusts
On the continental shelf of Portugal there are documented occurrences of polymetallic nodules on the Abyssal Plains. According to data from the International Seabed Authority, Fe-Mn crusts have been identified on the Madeira-Tore Rise, north of the Madeira Islands, and along the Mid-Atlantic Ridge on the northern boundary of the EEZ of the Azores. More recently, dedicated CSEP cruises have also allowed occurrences of Fe-Mn crusts to be identified on seamounts south of the Azores, and have proved their existence on the Madeira-Tore Rise.
Fig. 3 - Fe-Mn crusts samples
Fig. 4 - CoFe-Mn crusts rich in Co
During the course of the CSEP campaigns, the EMEPC has collected a significant number of samples of fauna and flora, water and sediment, most of them collected at great ocean depths (over 1,500 m). This collection has been enhanced by academic studies on biodiversity and genetic resources. However, there is still a long way to go until so-called “blue biotechnology” applications can be developed.
Fig. 5 - Biodiversity in the Lucky Strike hydrothermal field