I'm assuming you meant subsistence farming? If so then yes, it would be a large problem because they would then not have enough food to feed themselves.
Which countries are an option?
Answer:
It fosters friendly relations between its members, it solves international problems and promotes human rights, and it harmonizes its members' actions.
Explanation:
If your question is literally how long they could remain without water, the answer is 1-2 days with major side effects, and 3-4 with certain death.
Answer:
Aquatic animals and organisms thrive in coral reef habitats/ecosystems. The biodiversity of different organisms (like fish) are abundant because of the habitats (like anemone), algae, and phytoplankton that live off the area. The destruction of the coral reef by polution can cause a disturbance in the balance of life. For example, the bacteria and algae (autotrophs) that live off the sides of pieces of coral would die off causing the fish and other things that way them to die off and then the fish that consume those animals would die off.
In shorter terms: the physical damage would throw off the balance of the food web/food chain and would destroy habitats of thousands of organisms causing them to die off.
Hope this helps! :D