In this satellite image taken on March 22, 2021, we see red swirls in the ocean – these are plankton microorganisms, which have evolved significantly after a possible disruption of their ecosystem. This colored water was also discovered on March 23, 2021 from the SEM/REV test platform off Croisic, and a team from the Ecole Centrale in Nantes reported on the participatory website. phenomere.

Here, the pigment responsible for the red coloration is phyqueerythrinIt is present in most red algae, as well as in some cyanobacteria and some types of bacteria Cryptophytes (Single-celled microorganisms). In this case, the pigments were synthesized inside a crypt cell, which itself consumed by a ciliated microorganism called red misodinium, observed at Vendée on March 27, and then at the port of Sables-d’Olonne on March 28, 2021.

This tiny, brittle frill of about 40 micrometers in size continues to grow in the buildings of ” Roscoff Cultural Group ”, at the Roscoff Biological Station. By studying them, we especially hope to better understand the toxicity of dinoflagellates. dynophysisWhich are the preferred prey, including: dynophysis It is known to produce toxins that cause diarrhea symptoms in the consumer of shellfish if contaminated outside safety limits, which are regulated by the state and monitored by IFREMER.

Phytoplankton, the lungs of our planet

Cryptophytes, mixotrophic ciliates, and dinoflagellates are various examples of plankton, the group of single-celled microscopic organisms that drift with currents and live especially in pelagic marine waters.

Little known, since it is invisible to the naked eye, phytoplankton are nevertheless the lungs of our planet. Thanks to photosynthesis, more than half of terrestrial oxygen is produced and part of the carbon dioxide of natural or human origin is produced and consumed (about half of the emissions remain trapped in the atmosphere, the rest is absorbed by carbon sinks, such as oceans, forests, peatlands, and tundra).

Phytoplankton are also essential to marine life, as they form the basis of ocean food chains or “food webs,” such as red misodinium who feeds dynophysis.

Read more: In the ocean, how plankton adapted to their turbulent environment

participatory science project phenomere It aims to improve knowledge through observation, imaging, sampling and reporting of colored water. This will lead to a better understanding of these phenomena by scientists in the long run.

The Water Colored Ring in March 2021 illustrates the synergy between the various means of observation available to us: When weather conditions are favourable, satellite observations allow an overview of the colored waters reported in the Phenomer, thus providing a more comprehensive geographical and temporal context. In addition, the Phenomer’s observations provide valuable information on the species responsible for the colored waters, thus improving the processing of satellite images made within the framework. Lasha research project (Laboratory for remote sensing satellite experiments of harmful algae) from the University of Nantes, funded by the National Center for Space Studies.