Explore the Bay Game

BAY GAME PLAYERS				CONCEPTS IN DEPTH
Animal Farmer	Crop Farmer	Land Developer	Waterman	True Cost of Food	Understanding Bay Health

The Health of the Chesapeake Bay

Nutrients and Dissolved Oxygen

Physical Processes

Biological Processes

What Can I Do?

Biological Processes

Nitrogen and phosphorus provide food to phytoplankton, tiny plants that live on the surface of the water. Phytoplankton are the basis of the marine food web, but when they are too plentiful they can create problems in the Chesapeake Bay. Phytoplankton blooms can reduce the amount of light available deeper in the Bay, and result in lower dissolved oxygen.

Healthy ecosystem Some phytoplankton are consumed by zooplankton, tiny animals that live in marine systems. This is the start of an energy flow that begins with phytoplankton and ends with fish and their predators. This is what we typically think of when we think of a healthy Bay environment.		Unhealthy ecosystem An alternative energy can also be established, however. Zooplankton are not able to consume all of the phytoplankton that are produced. Some fall unconsumed to the Bay floor, where they decompose, a process that consumes oxygen. The remainder are consumed by bacteria, which are very plentiful in the Chesapeake Bay in the spring and summer. Bacteria are consumed by protozoa, which are tiny single-celled organisms.

In the summer, nutrients are added to the Bay at a slower rate, but there are extra nutrients on the bottom of the bay that are recycled to the surface for phytoplankton to feed on.  Scientists have discovered that nitrogen that comes into the Bay over the course of the year is only enough to sustain 10 to 20% of the phytoplankton that grow in the Bay.  This means that the rest of the nutrients come from recycling nitrogen and phosphorus that never leave the Bay.

These process repeat in a cycle that results in lower and lower amounts of oxygen available in the water. These are good conditions for bacteria, which can live without oxygen, but bad conditions for fish, crabs, and other important species, which will have to flee from these conditions or die. The area of low dissolved oxygen in the bay grows in the spring and summer, but essentially disappears in the winter.

SPRING

SUMMER

 

Explore these and other related processes in greater detail in the video below.

Source: NOAA Satellites Environmental Visualizations Laboratory.

Hover over steps in the process to explore in greater detail.