Selective breeding and <span>natural selection are similar  because  they are both giving certain traits to offspring.
DIFFERENCE: 
</span>natural selection-Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
selective breeding-Selection by humans for breeding of useful traits from the natural variation among different organisms
        
             
        
        
        
As the question is incomplete and there are no statements available based on which the question can be answered. But based on the knowledge it can be answered.
Answer:
Most of the corals contains photosynthetic algae which are known as zooxanthllae which lives in the tissues of the corals. Algae and corals have mutualistic relationship.
The corals provide algae space to live and algae provides coral  food such as glucose and glycerols to them which are considered as products of photosynthesis.
If the producers are hampered by the catastrophic event then the main source of the food will be hampered. There will be less or no food source for the corals which covers a large area in the marine ecosystem.
There are chances that there will be more load on the other photosynthetic organism in water as there will be more population dependent on them for food.
Hence, if there is a loss of habitat for these protist other levels of food chain will be affected due to inter connection.
 
        
             
        
        
        
Can you clarify the question