When animals eat plants or other animals in order to survive, there is a flow of food energy through the ecosystem. What starts out as energy from the sun becomes food energy created by the green plants that use photosynthesis to grow and reproduce. These plants are the producers and the base of food chains and complex food webs. Read more
As one thing eats another, the layers of the food pyramid narrow. These layers, called trophic levels, represent available energy. Animals at each trophic level depend on animals living in the levels below them for food energy. The largest amount of available food energy is found on the first trophic level, the base of the pyramid. Less than 10% of the amount of food energy that is available in one level is available to the animals in the trophic level just above. That means each higher level can support fewer and fewer organisms.
Try to arrange all of the species into their correct place in the food pyramid. You can use the Check button at any time to see how you are doing.
In many coastal systems, primary production is almost entirely a function of the phytoplankton. Even in salt marsh estuaries, where marsh grass and sedge biomass can greatly exceed that of algae, phytoplankton can contribute substantially to overall primary production. Phytoplankton plays an integral role in coastal food webs with primary production almost entirely a function of this microscopic organism. Phytoplankton are highly sensitive to the environmental variables within the estuary and respond quickly to changes in the estuary. Consequently plankton are often the first to be impacted by climate change. As the climate shifts it will likely change the abundance and types of species present in the estuary. While most scientists expect climate change to cause dramatic impacts to phytoplankton and the estuary food web, little is known concerning how these changes will occur.
To learn more about the estuary and climate change connection, check out Climate Extensions main page.
Downloads Used with this Activity
VIMS Marine Plankton Food Web and Climate Change White Paper
Additional Web Resources