What are some animals in an estuary that are primary consumers?

In an estuary, primary consumers include various herbivorous species that feed on aquatic plants and phytoplankton. Common examples are grazing invertebrates like snails, crabs, and certain species of shrimp, as well as fish such as mullet that consume algae and submerged vegetation. These organisms play a crucial role in the estuarine food web by converting primary production into energy for higher trophic levels.