Answer:
The sentence that is not true about the two passages is Both authors state that coral reefs are polluting the ocean floor.
Step-by-step explanation:
Both passages are making a statement about two main points related to the coral reefs, first of all, they both mention how important they are to the ecosystem for marine life and how there are some groups of protection of it to preserve the balance of the species, then it is not possible to say that they are polluting as if they were something negative to the ocean.