SEAMOX: The Influence of Seamounts and Oxygen Minimum Zones on Pelagic Fauna in the Eastern Tropical Atlantic - Cruise No. MSM49 - November 28 - December 21, 2015 - Las Palmas de Gran Canaria (Spain) - Mindelo (Republic of Cape Verde) (English)

Cruise MSM49 focused on the impact of the oxygen minimum zone (OMZ) and of a shallow topographic feature, Senghor Seamount, on the abundance, distribution, diversity and trophic structure of the medium-sized pelagic fauna (macrozooplankton, micronekton, and squids). Using a combination of optical and multiple net systems, the ecological zonation of these oceanographic features in the Cape Verde area was investigated and collections for detailed foodweb studies were performed. A total of 10 stations to the north, east and south of the Cape Verde archipelago were sampled, including the Cape Verde Ocean Observatory (CVOO), Senghor Seamount summit and middle slopes, a cyclonic eddy, and oceanic stations with differing intensities of the OMZ. Preliminary results show that organisms were abundant in the oxygen-poor layers; the communities there were apparently dominated by gelatinous zooplankton. Pelagic communities differing from the surrounding ocean were observed at Senghor Seamount and in the core of the cyclonic eddy.