The strong currents around seamounts, the high depth gradients and the dominance of hard substrates such as bed rock, cobbles and gravel favour the occurrence of very distinctive and diverse biological communities. Seamounts summits that reach the euphotic zone are dominated by kelp and calcareous algae, whilst diverse soft sediment communities are common towards the base or on terraces or flat summits, hosting a wide diversity of burrowing and interstitial organisms and epifauna as well. Other important key biotic components in seamounts are deep-sea sponges and cold-water corals, as they form structurally complex habitats that sustain high abundance and biodiversity at the seafloor, and are known as feeding, spawning and nursery grounds for a range of organisms, including commercially important fish species. Both deep-sea sponges and corals are slow-growing and long-lived, and therefore slow to recover from perturbations, including physical damage from bottom fisheries, hydrocarbon drilling and seabed mining. For that reason these fragile species or associations of species have been listed as vulnerable marine ecosystems (VME) of utmost conservation priority. Moreover some of the associated seamount fish species are long lived, slow growing and late maturing. Some of them form dense aggregations for reproduction, becoming easy targets to fishing activities. In this sense there is an urgent need for efficient research and monitoring activities aiming the definition of sustainable management measures that guarantee an efficient protection of these ecosystems. Comprehensive baseline mapping to spatially discriminate the distribution of abiotic (e.g.: topography, bathymetry, substrate type) and biotic attributes (e.g.: biological communities’ and biodiversity) is among the key activities to support those measures as well as to help designing long-term efficient and cost-effective monitoring plans.
The tasks proposed within WP2 will provide important baseline scientific information through the identification, classification and mapping of deep-sea benthic marine habitats/biotopes with high biological value, which may require conservation and informed management actions. The assessment of biodiversity in the different habitats will also be of key importance for the mentioned actions. The deep-sea benthic mapping of marine habitats/biotopes will be undertaken in collaboration with the Norwegian Institute of Marine Research to benefit from experiences made and methodology developed as part of the national mapping programme MAREANO. The outputs will also scientifically support Portugal’s purposes of creating two open ocean MPA encompassing the Madeira-Tore and the Great Meteor seamount complexes. This objective is part of the necessary measures to take (included in the submitted MSFD monitoring programme and programme of measures) for the continuous assessment of the environmental status of marine waters aiming the good environmental status achievement, as well as the sustainability of the Portuguese marine natural resources and to preserve the economic activities which depend on the benthic environment.