Marine systems are facing an increase in the frequency of extreme events and especially climate change scenarios foreshadow the increase of heat waves in the future. Increasing heat waves can alter planktonic diversity, interactions between different groups, and key processes. According to modelling forecasts for the future increase in the frequency of heat waves, an in situ mesocosm experiment is currently being conducted (end of April and May 2022) at the CNRS-MEDIMER infrastructure (city of Sète in southern France). In this experiment, triplicate in situ mesocosms are heated to +5°C compared to the natural surrounding water temperature for five days and triplicate other in situ mesocosms act as a Control following the natural surrounding water temperature. After this first period of heat wave (HW1), all mesocosms are followed for a period of five days without heating (Post HW1). This experimental protocol is repeated once more with the periods called HW2 and Post HW2. In this way, the planktonic communities will be subjected to two consecutive periods of heat waves and post-heat waves, and the results will be compared with those of the Control mesocosms. In this experiment, two teams, of five and three researchers each, as well as a trainee participate, all supported by the AQUACOSM-plus Transnational Access (pictures below).
The HEATS-ZOO team: Sultana Zervoudaki (team leader, GR), Jonna Engström-Öst (Expert, FI), Maria Protopapa (Post-doc, GR), Athanasia Sakavara (PhD, GR), Adriana Koutsandrea (MSc, GR), focusing on the composition, production and feeding of the zooplankton community and estimation of eco-physiological processes, such as oxidative stress and antioxidants in selected dominant zooplankton species. They also manipulate mesozooplankton from the lagoon, incubating them into bottles filled with water from the experimental mesocosms and expect that potential changes in the food quality and community under heat waves will affect the responses of different zooplankton.
The Heat-VIRBAC team: Manuel Martinez Garcia (team leader, ES), Maria Alvarez Sanchez (PhD, SP) and Aitana Llorenç Vicedo (PhD, SP), studying viral and cellular metagenomics along with single-cell genomics, including 16S (prokaryotes) and 18S (protist) rRNA gene Illumina and Nanopore Sequence, vesicle abundance and in situ BONCAT-tagging community to monitor metabolically active microbes and viruses. In addition, Katrina Feliciano (FI) participates in this experiment as a trainee.
Project Leaders: Francesca Vidussi and Behzad Mostajir
Pictures provided by @B. Mostajir