These tiny plants and animals drift in the water, largely at the mercy of the currents and tides. Some of the organisms move up and down in the water column to take advantage of light. Others will drop below the pycnocline, a layer where the increase in salinity is more pronounced, to avoid being washed out to the ocean.
Phytoplankton are tiny, single-celled plants.
Although there are many species of phytoplankton, the major types in the Bay are diatoms and dinoflagellates. Like other terrestrial plants, phytoplankton are the primary food producers in aquatic systems. Through a process known as photosynthesis, phytoplankton convert energy from the sun into organic compounds that they use as food. A byproduct of photosynthesis is the production of much-needed oxygen. The largest concentrations of phytoplankton occur near the water's surface, where light is readily available.