Cyanobacteria are also known as blue-green algae. These microorganisms are single-celled and prokaryotic, meaning they have no organelles that assist them in carrying out metabolic activity. They are the oldest living forms on Earth, with fossil remains as old as 3.5 billion years. Their blooms are common in saltwater areas and can happen anywhere in shallow, warm waters.
Silicoflagellate are distinctive for the flagellae that they use to propel themselves through the water. Flagellae behave like little tails; the microorganism uses the flagellae the same way a tadpole uses its tail to push itself through the water. This particular phytoplankter also secretes silicon dioxide as metabolic waste.
Coccolithophoroids are porous, round, single-celled organisms. The blooms they create produce a large amount of chlorophyll that reflects enough light to be seen from space. When these organisms die, they sink to the ocean floor and create chalk -- the same chalk used to write on a chalkboard.
Diatoms are a common category of bloom species that proliferate in the Gulf of Maine in warm weather. They are the first to appear in the beginning of a bloom because of their ability to reproduce very quickly. This is especially true if the water contains high amounts of silicic acid because the diatoms need this to produce their outer cell walls.
The dinoflagellates have flagellae that assist them in moving through the water in a spinning motion. Unlike other phytoplankters that survive strictly through sunlight and photosynthesis, dinoflagellates have the ability to directly ingest food. Dinoflagellate blooms are large and toxic. They poison fish and cause lung irritation in humans. These are the organisms responsible for the dangerous Red Tides along the coast of Florida.