The reasoning behind this is because these unidentified plants could be used to cure diseases, used for food, and many scientists may even use these plants to create cosmetics. I really hope this helps and I just thought this off the top of my head so its may not be 100% accurate but its the basics of it.
Answer:
zooplankton feed on phytoplankton, the main producers of the ocean, that provide a strong link for every marine food chain. without these consumers, there would be very little methods for energy to be distributed through the oceans ecosystem and life would diminish within the ocean.
Explanation:
1. Saltwater is completely different from freshwater
2. Only certain animals can live in saltwater/regular water
3. Plants may not require things from saltwater to survive, things can die