Ecosystem is a living system, where living organisms interacts with their environment and among each other. 
Due to some hazardous processes like, Global warming, Green-house effect, increasing pollution, ecosystem is degrading. 
We live in our Ecosystem, if it will get destroyed, our existence would be impossible. So, in order to save ourselves, we need to save it.
That's why biologists, concerned about ecosystem disruption
Hope this helps!
        
             
        
        
        
The relationship between planets and moons are: moons are natural objects that orbit planets, while planets orbit the sun
        
             
        
        
        
Answer:
Sun--> Plankton---> seabass---> otter
Explanation:
plankton use photosynthesis to absorb energy from the sun to create food. sea bass consume plankton by filtering them from the water while otters will catch and eat the seabass
 
        
                    
             
        
        
        
Answer:
i believe that the answer is sedimentation
 
        
             
        
        
        
<span>Most organisms, including humans, can't use the free gaseous form of nitrogen found in the air. We need other organisms and natural processes to "fix" nitrogen into a solid form that plants and animals can use. Most of the nitrogen that plants and animals use is made by bacteria.</span>