This document summarizes different types of aquatic ecosystems. It describes how water depth influences aquatic life, with a photic zone where photosynthesis can occur near the surface and an aphotic zone below where it cannot. It also discusses plankton, benthic organisms on the bottom, freshwater ecosystems like streams and wetlands, and marine ecosystems including intertidal zones, coastal oceans, and the open ocean.

1. Lesson Overview 4.5 Aquatic Ecosystems