Focus on Fish Gallery Guide Focus on Fish Final | Page 30

Food Chains and Webs
A food chain is a series of links starting from "producer" species
(such as grass or trees) and ending at a top predator species
(like grizzly bears or killer whales). A food chain shows how the
organisms are related with each other by the food they eat.
Each food chain is one possible path that energy and nutrients
may take as they move through the ecosystem. However, each
living thing in an ecosystem is part of multiple food chains.
A food web consists of all the food chains in a single ecosystem.
All of the interconnected and overlapping food chains in an
ecosystem make up a food web. All organisms in an ecosystem
are connected on numerous levels. Just because humans don’t
eat “phytoplankton salad” for lunch doesn’t mean that we are
not concerned with the health and amount of phytoplankton in
the Great Lakes ecosystem. Every living thing is in a
relationship with every other living thing in an ecosystem!
The diagram on the next page is adapted, with permission,
from The Life of the Lakes.