They are the energy base of the food chain for all aquatic organisms, without them all aquatic organisms would most likely parish.
        
             
        
        
        
Why does that person keep putting that in the comments ugh 6
        
             
        
        
        
Around 3-4% is the answer.
        
             
        
        
        
Paleontology is the study of the history of life on earth as based on fossils.