ChEReef 2022

Type Oceanographic cruise
Set This cruise is part of the set CHEREEF-OBS
Ship Thalassa
Ship owner Ifremer
Dates 03/08/2022 - 30/08/2022
Chief scientist(s) MENOT Lenaick ORCID, TOUROLLE Julie ORCID

LABORATOIRE ENVIRONNEMENT PROFOND

Centre Ifremer Bretagne

ZI Pointe du Diable

CS 10070

29280 Plouzané

+33 (0)2 98.22.43.04

https://www.umr-beep.fr/
DOI 10.17600/18000571
Objective

The ChEReef 2022 cruise, the second of six annual ChEReef cruises, is part of the ChEReef-OBS series of cruises that aims to deploy, support and then recover after five years the MARLEY (Monitoring deep seA coRaL EcosYstem) autonomous observatory deployed in the Lampaul canyon (Bay of Biscay) in 2021.

As part of the European Life Integrated Marha project, which aims to understand and improve the conservation status of marine habitats, and the ANR ARDECO project, the ChEReef project is working to assess the state of health of cold-water corals in the Lampaul canyon, 200 km off the coast of Brittany, and particularly the colonial scleratinians that form reefs and have fundamental ecological functions for biodiversity. Like tropical reefs, they provide habitat and shelter, feeding, recruitment and nursery areas for many species.

The objective of the ChEReef project is to describe the dynamics of cold-water coral reefs in the Bay of Biscay: to understand the distribution of coral habitats on the scale of the canyon, but also to understand the temporal dynamics of the engineer species that structure these habitats.

This cuise has thus made possible the follow-up of the spatial and stationary approaches to the evaluation and monitoring of the conservation status of this habitat "Reefs" in the Lampaul canyon initiated during the ChEReef 2021 cruise. The objective is also to better understand the role of geomorphological, hydrodynamic, sedimentary and anthropic factors in the distribution of corals within the canyon.

To answer these questions, the cruise used the Victor 6000 ROV to precisely explore the canyon and produce 2D and 3D mosaics of targeted reef habitats. Two mooring lines with particle traps, ADCPs and turbidimeters were deployed and will characterise currents and particle fluxes at the canyon scale. In-situ experiments were continued to assess growth rates of reef scleractinians and coral colonies were collected for heating and acidification experiments in the pressure aquariums.

The MARLEY autonomous observation station was recovered and redeployed until next year. Its aim is to monitor the dynamics of corals and their environment. It will allow daily observation of a coral colony and its immediate environment for 5 years while measuring the physical, chemical and hydro-sedimentary parameters of the coral habitat. The deployment and maintenance period of the observatory is limited by the duration of the Marha project, and the observatory will be definitively recovered in 2026.

Data managed by SISMER

Sampling operations

Dives

Moorings