researchers are studying the adaptability of oysters to the living conditions of the future

“Here, it’s really a sampling room!” In this white-walled room at Ifremer, theFrench Research Institute for the Exploitation of the Sea, north of Brest, scientists carry out a sort of autopsy of the oysters which are projected into the decades to come. VSIfremer researchers and Cnrs are studying the adaptation mechanisms of oysters when they are immersed in a warmer and more acidic ocean. To do this, the oysters grow a container that reproduces living conditions in the ocean in 2050, 2075 and 2100, according to the most likely scenarios considered by the IPCC.

While the One Ocean Summit – the international summit on the oceans – is being held in Brest until Friday February 11, the health of the oceans has never been so worrying. Overheating, acidification, asphyxiation, pollution: the UN is alerting States to the impact that these phenomena will have on the oceans in the years to come and more particularly on the organisms that live there. “It will allow us to assess the ability not to acclimatize today’s animals to tomorrow’s conditions, but their ability to adapt”, explains Fabrice Pernet, researcher in mollusc physiognomy at Ifremer.

In the tank, the oysters are subjected to the living conditions of 2075, the temperature has been increased by 1.6 degrees and the acidification is significantly increased. If it is not fatal for the oysters, it remains a major disturbance, continues Fabrice Pernet. “We know that one of the big problems with acidification is the drop in carbonate content in seawater. Carbonates make up the shells. make by themselves.”

“They have little enzymes that allow them to do that, but it costs them energy that they don’t put into other things, like reproducing, fighting pathogens. If the environment changes, there will be potentially a physiological cost to these organisms.”

Fabrice Pernet, researcher at Ifremer

at franceinfo

The acidification of the oceans comes from the carbon dioxide they absorb, which has reached a record concentration, but researchers are trying to find local solutions. For Frédéric Gazeau, researcher at the Villefranche oceanography laboratory, a stakeholder in this study, the solution could be to use algae. “What we are doing as part of the project with Ifremer Cocorico 2 is precisely to assess the possibility of co-cultures between oysters and mussels, and seaweed, says this specialist. Because algae obviously have this ability to use CO2 to make organic matter and produce oxygen and therefore theoretically promote the growth of organisms in culture.” And the study will be done over time, with several generations of oysters, an unprecedented process.