Grade 8 Integrated Science Chapter 19 Lesson 2 on different aquatic ecosystems. This lesson gives short defining characters of freshwater, ocean, wetland, and estuary ecosystems. Freshwater ecosystems include river, streams, lakes, and ponds. The ocean section describes the open ocean, coastal ocean, and coral reefs. There is also a short section about intertidal zones and layers of the open ocean. The objective of the lesson is that students should be able to identify defining characteristics of each ecosystem and be able to compare and contrast.