Marine Resources on the Extension of the Continental Shelf
The non-living resources of the seabed are increasingly seen as a potential 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 and energy (including methane hydrates) from the the deep sea is becoming increasingly feasible. Some of these resources are found on the continental shelves beyond 200 nautical miles, making these areas new potential sources available to coastal States.
The exploration and scientific knowledge on the resources of the l seabed and subsoil in areas under national jurisdiction remains limited and poorly characterized. However, the data and knowledge gained over the years through marine scientific research and oceanographic cruises promoted by the CSEP have allowed the identification of the areas with higher potential for their study.
Fig. 1 - Deep Sea Resources
Metallic Mineral Resources
Metallic mineral resources have been known to exist in the Portuguese EEZ for several decades. Known resources include ferromanganese 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.
Polymetallic Sulphides (Cu, Zn, Ag and Au)
Recent scientific exploration of the seabed, which reached its heyday in the nineties of the XX century, especially in the Azores region, has demonstrated the existence of metallic resources associated with hydrothermal fields. Various international oceanographic cruises 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 future exploitation of mineral reserves that may form at water depths of 1,500-3,000m, which until recently was mere science fiction, may be technologically feasible by the second half of the twenty-first century. Apart from the technological challenge there is still a lot to be done in order to assess and fully understand the environmental impacts that may arise from these activities. In fact, the existence of unique ecosystems in the active hydrothermal fields poses new and formidable challenges to the sustainable exploitation of this type of mineral deposits. Fostering the knowledge on the formation and evolution of sulphide deposits formed at active sites may give important clues for the development of new tools and technology focused on the identification of the inactive analogues where these fragile ecosystems are not present.
Fig. 2 - Chimney of the Lucky Strike hydrothermal vent
Fe-Mn Nodules and Crusts
In the EEZ and continental shelf of Portugal there are documented occurrences of ferromanganese nodules on the Madeira-Tore rise (Muiños et al., 2013). According to data from the International Seabed Authority, Fe-Mn crusts have been also identified in this area, as well as to the north of the Madeira Archipelago, and along the Mid-Atlantic Ridge in the northern boundary of the Portuguese EEZ in the Azores area. More recently, dedicated cruises within the scope of the CSEP have allowed recognizing new occurrences of Fe-Mn crusts on the seamounts located to the 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
Natural Living Resources
The marine environment comprises more than 70% of the Earth’s surface, and the deep sea covers the majority of this area.
The high variability of seafloor habitats - seamounts, spreading ridges, canyons, plains, trenches - along with the different physico-chemical conditions of the deep sea promotes biological diversity. The genetic resources constitute the basis for blue biotechnology, which uses organisms or their DNA in the development of new products comprising medicines, cosmetics and innovative industrial applications.
Throughout the last decades, scientific knowledge of the deep sea has increased rapidly, and bioprospecting has been essentially focused on fundamental research, studying the biodiversity and characterizing the different ecosystems. These communities namely of coral gardens and deep sea sponge aggregations provide a complex habitat structure and increasing local biodiversity by providing shelter for an unknown number of species, as well as spawn grounds for commercial fishes. The deep sea coral gardens also provide compounds useful in fighting antibiotic resistant infections.
Back in the 70’s of the XX century, the first researches have been focused on hydrothermal bacterial communities. Since their discovery in 1977, hydrothermal vents have been surprising for the great diversity they host, in an environment where sunlight does not penetrate. In these communities, the entire food chain is based not on photosynthesis but on microorganisms (Bacteria and Archea) able to use the chemical elements provided by the hydrothermal fluids as the energy source to produce organic material.
More than five hundred species have been described in these ecosystems, being most of them exclusive with this type of habitat. They are of particular interest for blue biotechnology because they live in extreme environments, similar to those that occur in industrial processes, with a high range of temperatures, high pressures or high acidity. Those adaptations in the hostile environments can be used in improving industrial processes and reducing costs, particularly those related with the environmental impacts, which translates in benefits for all human kind.
Fig. 5 - Biodiversity in the Lucky Strike hydrothermal field