If you are witnessing this strange phenomenon of neon green sea, do not save the photo only for your Instagram account. At Ifremer, researchers need it to advance their study currently being carried out on these blooms of microalgae, regularly observed in Morbihan or Loire-Atlantique.
This Tuesday, they therefore launched a “call for citizen mobilization” to collect as many reports as possible this summer and advance research. Because if these episodes are not dangerous for humans, they are for shellfish and fish.
The microscopic algae, called Lepidodinium chlorophorum, produces “a large quantity of mucus which increases the viscosity of seawater and bacterial development,” indicates Ifremer. This visibly bother the oysters and mussels in the surrounding area since in 2018, for example, many shellfish mortalities occurred following the observation of green colored waters in these same areas.
Participate via the Phenomer app
If the cause and effect link seems established, we must now better understand the phenomenon: does the water, which is more viscous, clog the gills of shellfish? Does the natural breakdown of mucus consume too much oxygen? Researchers need to go and see them on the spot and this is where citizens can guide them by reporting these blooms, which cannot be predicted but are generally more frequent in summer.
“These first elements of understanding are essential to be able to subsequently consider the construction of future predictive tools and the implementation of strategies in the event of blooms to reduce the consequences on local aquaculture production”, underlines Mathilde Schapira, researcher at Ifremer at the Morbihan Pays-de-la-Loire environment resources laboratory and responsible for the Lepido-pen project.
Reports can be made via a dedicated app called Phenomer or on his website.