Phaeocystis
The flagellates in sea can have blooming periods and some of the genus produce a toxin and have fish-killing capabilities. Of the marine organisms belonging to the group small flagellates some have caused great damages, special to the fish and the fish farms.
The genus Chrysochromulina and Prymnesium are well-known names in the press from the blooming periods a few years ago. The genus Chatonella also is a feared algae. On account of the small size of each cell it is, for amateurs, almost impossible to identify the species. Only specialists can do so.
A small flagellate called Phaeocystis or jelly algae, occurs only in seawater and can produce blooms in great abundance.
Phaeocystis exist in two phases, a colony phase with a large number of cells inside a big ball of jelly, and the phase where the single cells are free-swimming. The cell has two flagella and in addition, a very short flagellum. The colony is rather big, up to 2-8 mm in diameter. In the start the colony is round like a ball but the older colonies are more patched.
The single cells in the second phase are extremely small, about 5 my, and so impossible to identify.
It seems to be an increase in occurrence of blooming periods of Phaeocystis and the explanation concerns about the increasing of pollution (eutrofication).
The jelly surround the cells is reserve-nutrition. The cells therefore can grow in the dark nights and under strong water movements. The colonies envelopes crests and a big layer of this crest can be set on the beaches on the continent and be harmful to the tourists.
The algae produces dimetylsulfid (DMS), a biogas with sulfur exposed to the atmosphere, and is a natural source for acid rain.
Phaeocystis is common i Norwegian fjords and the colonies can fill the fish tools with a brown substance.
