Main objective: MapGES 2021 is the continuation of our long-term strategy to map deep-sea biodiversity and identify Vulnerable Marine Ecosystems (VMEs) in the Azores using the Azor drift-cam video system. This year, we operated on the RV Arquipélago and on the FV Gotimar, based in the small island of Corvo. Due to an ongoing strike declared by the crew of the RV Arquipélago, our work focused in areas close to Faial harbor (mostly Faial, Pico and São Jorge islands). Using the FV Gotimar, we sampled the slopes of Corvo island for the first time ever. As in other MapGES cruises, the objectives were to (i) map the benthic communities inhabiting unexplored seamounts, ridges and island slopes, (ii) identify new areas that fit the FAO definition of what constitutes a Vulnerable Marine Ecosystem (VME); and (iii) determine the distribution patterns of deep-sea benthic biodiversity in the Azores region. The results of this cruise, when added to other contributions, will help to identify what are the main environmental drivers that determine the spatial distribution of deep-sea benthic fauna in the Azores. This cruise also provided valuable information in the context of Good Environmental Status (GES), Marine Spatial Planning (MSP) and provided new insights on how to sustainably manage deep-sea ecosystems.

Methodology: We performed several underwater video transects along the seafloor with the Azor drift-cam, a low-cost drifting camera system designed and developed at IMAR & Okeanos (University of the Azores). It allows the recording of high-quality underwater video images of the seabed down to 1000 m depth. The system was deployed from the research vessel RV Arquipélago, owned by the Government of the Azores and from the Fishing Vessel Gotimar, owned by Mestre Pereira.

Scientific team Leg 1: Telmo Morato (chief scientist), Sérgio Gomes, Luís Rodrigues, Manuela Ramos, Guilherme Gonçalves, Gerald H. Taranto
Scientific team Leg 2: Telmo Morato and Carlos Dominguez-Carrió (chief scientists), Sérgio Gomes, Luís Rodrigues, Gerald H. Taranto, Manuela Ramos
Scientific team Leg 3: Carlos Dominguez-Carrió (chief scientist), Sérgio Gomes, Luís Rodrigues, Gerald H. Taranto, Guilherme Gonçalves

Cruise summary: The MapGES 2021 survey was divided in 3 legs, which were planned to explore the island slopes of Faial, Pico and São Jorge in central Azores, and Corvo island in the western group (Table 1, Figure 1). Overall, 147 dives (out of 155 stations) were accomplished in 17 sampling areas, which include the slopes of 4 different islands (Table 2). During Leg 1, from 15th to 23rd July 2021, we performed 61 dives (out of 64 stations) with the Azor drift-cam, covering 31 km of the seafloor and producing 61 hours of video footage. This leg surveyed the deep-sea benthic communities of the slopes of Faial and Pico islands on board RV Arquipélago. During Leg 2, from 10th to 16th August 2021, we performed 18 dives (out of 20 stations) with the Azor drift-cam, covering 8 km of the seafloor and producing 20 hours of video footage. In this leg, we surveyed the slopes around Corvo island for the first time, on board the FV Gotimar. In Leg 3, which lasted from the 25th of August to 15th September 2021, we performed 68 dives (out of 71 stations) with the Azor drift-cam, covering 48 km of the seafloor and producing about 68 hours of video footage. Leg 3 explored the benthic communities on the slopes of Faial, Pico and São Jorge Islands on board RV Arquipélago. 

Main achievements:
1.    During the MapGES 2021 cruise we completed almost 150 underwater video transects between 100 and 970 m depth with the Azor drift-cam, adding up to around 150 new hours of underwater video footage of seabed habitats. As in previous years, the presence of many lost fishing lines made our deep-sea exploration challenging. After having the Azor drift-cam caught on several lines, we managed to get free on all occasions with only minor damage. These collateral fishing impacts, which limit the acquisition of deep-sea biodiversity data to inform management, deserve to be better quantified. 

2.    We completed the first visual survey of the slopes of Corvo island, with a total of 18 successful dives with the Azor drift-cam on board of a local fishing vessel, at depths between 130 and 970 m, covering the whole perimeter of the island. The slopes of Corvo island were mostly covered by soft sediments with some basaltic outcrops. In most areas explored, the octocorals Viminella flagellum and Acanthogorgia sp. formed large aggregations together with the demosponge Phakellia ventilabrum. Sporadically, and still within these gardens, we also observed small colonies of the fan-shaped octocoral Dentomuricea aff. meteor and the “bubblegum” coral Paragorgia johnsoni. The black coral Elatopathes abietina was alos found on most of the dives, forming large but scattered aggregations, while the species Stichopathes gravieri, Parantipathes hirondelle and Leiopathes glaberrima were occasionally present.

3.    The island slopes around Faial island were mostly covered by soft sedimented and deposits of coral rubble at the base of the slopes, with marine snow visible on the water column. The small ridge in Faial NW (near Praia do Norte) hosted an impressive and diverse aggregation of Candidella imbricata and Errina atlantica, with other less abundant species such as Lophelia pertusa and Madrepora oculata, usually over a bed of dead coral framework. Hidden below the rocky overhangs, large colonies of the black coral Leiopathes cf. expansa were observed. This area also contained an assemblage of the “bubblegum” coral Paragorgia johnsoni in its usual red and white morphotypes. Some of the small seamounts of this area may fit some of the FAO criteria that defines what constitutes a VME. 

4.    Throughout the dives conducted during this cruise, many commercially important fish species were commonly recorded, such as the bluemouth rockfish (Helicolenus dactylopterus), orange roughy (Hoplostethus atlanticus), silver roughy (Hoplostethus mediterraneus), and congers (Conger conger), reinforcing the idea of the slopes south of Faial Island as an important deep-sea area. 

5.    In the slopes south of Pico island, we observed several alfonsinos (Beryx decadactylus), one of the most valuable fish species in the Azores, with off-vessel prices reaching over 40 € per kilo. Among the vast range of coral species present in the areas, an impressive black coral colony of the genus Bathypathes was observed in Baixo de São Mateus. A vast aggregations of the bird’s nest sponge Pheronema carpenteri was also discovered in this area.