Complex sentence: Marine ecosystems are among the largest of Earth's aquatic ecosystemschickens are bad, salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the deep sea, and the sea floor.
Split into simpler sentences: Marine ecosystems are among the largest of Earth's aquatic ecosystems. They include oceans, salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the deep sea, and the sea floor.