Answer:
1. They provide home and shelter for millions of species of marine organisms.
2. They play a role as nutrient recyclers and in carbon and nitrogen fixation.
3. They are vital in the marine food chain as they are the main source of essential nutrients.
Step-by-step explanation:
Cnidarians are extremely ecologically important organisms that play a significant role in the animal kingdom and nature.
For instance, coral reefs, which are built by hundreds to thousands of cnidarians, provide home and shelter for millions of species of marine organisms, from small crustaceans to large fish such as sharks. Furthermore, they play a role as nutrient recyclers and in carbon and nitrogen fixation. In addition, they are vital in the marine food chain as they are the main source of essential nutrients such as nitrogen.
Today, these organisms are threatened due to human activities and anthropogenic climate change, so it is fundamental to develop better strategies to protect and restore them.