In Senegal, questions and fears arise after the sudden appearance of spots of a brown-orange color on the sea surface, on the Petite Côte, south of Dakar. Researchers from the Dakar-Thiaroye Oceanographic Research Center (CRODT) and the Research Institute for Development (IRD) conducted the study, with the participation of local residents: the culprit is a microalgae, harmless to the environment. humans, but potentially toxic to marine organisms.
as reported from Dakar,Charlotte Idrac
The effect was spectacular on the beaches of Saly, Somone and Popenguine, with suddenly very colorful water near the coast. A phenomenon that depends on what is called a “flowering”: the explosion of the concentration of a microalga explains Patrice Brehmer, researcher at IRD.
Noctiluca scintillans “In the present case, Noctiluca scintillans, it is a dinoflagellate that is toxic to the environment in an indirect way, the researcher explains. When explosions occur as in populations, it can produce strong ammonia concentrations and lower the level of dissolved oxygen in the sea.”
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The phenomenon would be linked to climatic factors, with a sudden rise in sea temperature, and the end of the trade winds, therefore northeast winds. It will quickly fade, according to the researcher, but can become recurring and disrupt the food chain. Noctiluca scintillans really consume diatoms, at the base of the food chain for small pelagics and Yaboy.
Long-term consequences “There are no problems with fish consumption,” Patrice Brehmer reassures.
Yaboy, in other words sardinella. This can have long-term economic and social consequences. For the scientist, there is no direct connection to the so-called “fish disease” appeared since 2020. But the phenomenon would require in-depth research.