The transfer of energy from organism to organism forms a series called a food chain. All the possible feeding relationships that exist in a biome make up its food web. In the wetland, as elsewhere, the food web consists of producers, consumers, and decomposers. These three types of organisms transfer energy within the wetland environment.

At the bottom of the food chain are the producers, which may be single-celled organisms such as bacteria and protozoa. The shallow wetland water lets in a lot of sunlight, which helps these organisms grow.

These primary producers are eaten by primary consumers such as the larval forms of frogs and toads, and larger animals such as shrimp and snails. Other primary consumers, such as small aquatic insects, shellfish, and small fish, feed on plant materials.

Primary consumers, in turn, are food for predators, such as larger fish, reptiles...