ADSR - Azores Deep-Sea Research

CRUISES / NICO Leg 12 2018

RV Pelagia cruise 64PE441: Rainbow hydrothermal vent, southern MAR, and Terceira 2018

Summary Show more ↓

This cruise resulted from the first real mutual collaboration with scientists from the Royal Netherlands Institute for Sea Research (NIOZ), namely Sabine Gollner. Deep-sea scientists from IMAR Instituto do Mar and Okeanos University of the Azores joined the RV Pelagia cruise 64PE441 to collect new imagery data using the NIOZ towed system on unexplored areas of the Mid-Atlantic Ridge south of the Azores. The overall aim of these explorations was to improve our knowledge on the distribution and abundance of large Vulnerable Marine Ecosystem indicator species and deep-sea commercial fishes in the large Azores region. This was the first time we visited seamounts in the South portion of the MAR in the Azores region. The results of this cruise contributed to identify the environmental drivers that determine the spatial distribution of deep-sea benthic biodiversity in the Azores region. It also provided valuable information in the context of Good Environmental Status (GES), Marine Spatial Planning (MSP) and new insights on how to sustainably manage deep-sea ecosystems.

Statistics

Transits

1420 km

Multibeam Bathymetry

0 km²

Filmed Seabed

9.5 km

Visited Areas

Stations

Dives

Video Footage Recorded

8 hours

Used Storage

0.82 Tb

Samples

No samples were collected for our groups

Highlights

The images recorded in Cavalo seamount revealed the largest area of high densities of the primnoid species Narella versluysi and Narella Bellissima ever observed in the Azores region until now. This community is extremely diverse, with these two corals associated with a wide range of other species, including several species of sponges as well as other large corals, including Paragorgia johnsoni, Pleuricorallium johnsoni and Callogorgia verticillata.
The upper slope of Cavalo seamount hosts some very large colonies of the gorgonian coral Paragorgia johnsoni, while in the shallowest part of the summit, the community is dominated by the yellow gorgonian Acanthogorgia sp. and very large colonies of the gorgonian species Callogorgia verticillata, together with many other accompanying species, including large numbers of the small Swiftia sp.
Based on a preliminary assessment Cavalo seamount may fit many of the FAO criteria that describe a Vulnerable Marine Ecosystem.
A very clear zonation pattern regarding the structure of the benthic communities was observed in São Jorge de Fora, with very well-defined species associations along the depth gradient. Overall, the area shows a high degree of sediment deposition and a low number of organisms within the communities identified.