It is a Diatom named “Aulacodiscus cf. kitonii” which is harmless for humans and for marine organisms.
Ximena Vivanco, researcher member of the noxious algae bloom and marine toxin working group of Instituto de Fomento Pesquero, Puerto Montt, said “the foam observed in recent days in Mar Brava, to the south of Faro Corona, near Ancud is a consequence of the presence of a diatom, of Aulacodiscus cf. kittonii specie, and it was stated that it is not harmful neither to humans nor to marine organisms, however, the sector presenting this “green foam” is also affected by the bloom of harmful microalgae known as Alexandrium catenella, and that the latter has been found in water samples of the same area.
Ximena confirmed that “the concentrated sample of foam was revised and it was stated that almost 100 % of the cells corresponded to diatom Aulacodiscus cf. kittonii. This specie has been previously reported as foam generator at shoal areas.
Even when the diatoms normally produce a yellow-brownish color, this time the color of the cells has a greenish tint, which could explain the color of the foam”.
The professional added that “in the foam sample, a very small amount of a single cell nano flagellated was detected and also only one cell deteriorated of A. catenella. It is not discarded that any other flagellate, which is very delicate and poorly resistant to be observed, may also be contributing to the foaming, but the large number of cells of this diatom, and the cleaning of the sample (almost no organic waste), it lets us assume that this is the main component and source of the green foam.”
Finally, Leonardo Nunez, Executive Director of IFOP said “The institute will be alert to inform properly from its advisory role, about new findings associated with red tide phenomenon”