Final answer:
Ecosystems consist of freshwater, marine, and terrestrial categories that support diverse life forms and are crucial for providing resources such as food and clean water. While they can heal themselves, they are considered fragile and essential for human survival.
Step-by-step explanation:
Based on the provided information, we can draw several conclusions about ecosystems. Ecosystems are not all marine-based, as they fall into three broad categories: freshwater, marine, and terrestrial. Each category houses different types of ecosystems characterized by their distinct environmental habitats and organisms. Freshwater ecosystems cover 1.8 percent of Earth's surface, while marine ecosystems make up 75 percent. Coral reefs are a part of marine ecosystems and are essential for a rich diversity of marine life. Ecosystems have the innate potential to heal themselves, which is a testament to their resiliency. They support a plethora of life forms, provide food, clean water, and are sources for many medications. However, ecosystems can be fragile, and their health and continuity are vital for the survival of species, including humans.