A challenging but successful cruise!

The Momarsat 2023 cruise was held from July 9 to July 28th 2022 onboard the French research vessel L’Atalante with the ROV Victor6000 at the Lucky Strike vent field - northern Mid-Atlantic Ridge - to carry out the yearly maintenance of the EMSO-Azores observatory.

Once again, we ensured the turnover of the full platform and sensor array and started another year of data acquisition! Led by Marjolaine Matabos, the team of 18 scientists from Ifremer, CNRS (IPGP, GET, MIO), University of Western Brittany (UBO) and University of the Azores worked together to achieve the substantial sampling plan paramount to the long-term monitoring of the vent field. Despite delayed departure of the ship, numerous breakdowns and technical issues with the submersible and the observatory infrastructure, all objectives were achieved. This success would not have been possible without the adaptability, support and flexibility of all teams and more particularly the ship crew, which had to adapt continuously to a changing program.

Momarsat 2023 team

The Momarsat 2023 great team on the R/V L’Atalante on the Lucky Strike vent field.

© Eloi de L’Estourbeillon/Momarsat 2023

This year, as part of the Deep-Rest project, we conducted new experimentations. The deposition of sulphide particles on vent assemblages using the SPIDER benthic chamber was used to examine their impacts on vent faunal biodiversity and physiology. On-board and in-situ incubations of the Bathymodiolus azoricus mussel to a fluorochrome aimed to assess their growth rate. Moreover, a new diffuse-flow site spotted to the south of the Cimendef sulphide structure appears promising for future integrated multidisciplinary studies. Marine life accompanied us all along the cruise with dolphins, sharks, tuna and whales. At the bottom, we had a nice and rare encounter...

Grimpotheutis octopusGrimpotheutis octopus

The encounter of Victor6000 with a Grimpotheutis octopus at 1697 m depth. ©Victor6000/Momarsat 2023

On the way back to Horta, cruise participants Jozée Sarrazin and Marjolaine Matabos, with Ana Colaço, were invited by the Azorean government to give a conference following the exhibition of Damien Roudeau drawings (from Momarsat 2022 cruise) at the Fabrica Baleia.

The EMSO-Azores observatory is part of the One Ocean Network for Deep Observation action of Ifremer endorsed by the UN Ocean Decade program (https://www.oceandecade.org/actions/one-ocean-network-for-deep-observation/).