I think not. Both of those nuisance algae’s favor low nutrients,
@Randy Holmes-Farley described a process in which Cynobacteria mat dissolved inorganic calcium phosphate and assimilated organic phosphate into its biomass.
http://cmore.soest.hawaii.edu/cruises/biolincs/microbes.htm
Nitrogen fixation by Cynobacteria converts Nitrogen gas into a nitrate molecule. This makes Earth a green planet.
MARINE BACTERIA
Marine bacteria are single-celled organisms that can be shaped like little spheres, rods, or (less commonly) spirals. The are often very small, with cell diameters of just a few microns (about 1/100th the width of a human hair). They perform all kinds of chemical processes in the open ocean, including most of the steps in nitrogen cycling.
Cyanobacteria are a large group of photosynthetic bacteria, some of which can
“fix” nitrogen, converting nitrogen gas into more biologically useful compounds. Cyanobacteria live in all kinds of environments, but are especially important in open-ocean ecosystems. They were formerly known as “blue-green algae” but are now recognized as a type of bacteria, not a type of algae (algae are eukaryotes).