Phytoplankton cannot swim on their own. Tides and currents move these tiny, single-celled plants from place to place.

Phytoplankton (or algae) are tiny, single-celled plants. They are the primary producers of food and oxygen in the Chesapeake Bay, forming the base of the food web.

Poor water clarity is usually caused by a combination of suspended sediments, organic matter and excess nutrients that fuel the growth of water-clouding algae. Weather also plays a large role in water clarity. Rain storms can wash dirt and pollutants into the Bay and cause the water to look muddy. During drier conditions, the water is usually clearer.