The Cabo Verde study area
The Cabo Verde archipelago is located along the north-west African coast, in the eastern tropical North Atlantic Ocean, and is comprises a group of 10 main islands that are volcanic in origin. The islands are part of the Macronesia biogeographic region, together with the Azores, Madeira and Canary Islands.
The Cabo Verde islands are rich in culture, history and beautiful landscapes. A curious fact about the archipelago is that it was the first stop of the HSM Beagle expedition in 1832 – the famous expedition that led to Charles Darwin’s findings on evaluation evolution and natural selection. In the first chapter of his book The Voyage of the Beagle, Darwin describes his amazement at the geological scenery he found on Santiago Island.
Regarding the marine realm, the geographic position of Cabo Verde makes it especially interesting since it sits in an area where tropical and subtropical ocean fronts and currents meet. Local upwelling in the region is induced by seamounts and islands, but it is mainly the Canary Current–Eastern Boundary Upwelling Ecosystem that is responsible for the formation of mesoscale eddies known to strongly affect the oceanographic conditions around Cabo Verde. Because of the presence of these eddies, and area that would normally be considered oligotrophic stands out for its high nutrient levels and high biological productivity. This, in turn, creates a low oxygen minimum zone (OMZ) that forms between 300 to 600 m deep in the water column.
The oceanographic conditions make Cabo Verde a marine biodiversity hotspot of interest, reflected in the potential of its fishing resources that include around 180 different targeted commercial species. Despite this potential, scientific knowledge about the marine setting around Cabo Verde is still scarce, particularly so when it comes to life in the water column below 200 meters.
Cabo Verde deep waters
The deep-sea fauna of Cabo Verde has been previously explored by marine scientists. German research expeditions conducted by GEOMAR provided the first precious data and footage using the JAGO submersible and ROV Kiel6000. Thanks to these, we have an idea of the megabenthic fauna we might expect to find in some of the locations to be explored during iMirabilis2. The GEOMAR images reveal a stunning seascape covered by volcanic rocks with the presence of some octocorals, bamboo corals, black corals and sponges. iMirabilis2 is fully dedicated to exploring and mapping the deep-sea benthic ecosystem of Cabo Verde.
Predicted scenarios for future ocean conditions indicate an expansion of oxygen minimum zones worldwide. This is why it is critically important that we better understand the effects of low oxygen concentrations on deep-sea biological communities, improve our insight into ecosystem functioning, and evaluate how these ecosystems might respond and adapt to such conditions – now and in the future – and especially in unexplored deep-sea areas, such as Cabo Verde.
