Question

if there were no I'll get there would be no fish in the sea comment

Answer 1

if their will be no fish so our world will be not beautyfull

Answer 2

algae are the main source of productivity in sea. they prepare there own food with the help of photosynthesis. they are food for many small  aquatic animals living in the sea. hence the algae is food for small fishes and small fishes are food for big fishes. it is like a food chain. hence we can say if there were no algae there would be no fish in the sea.