Even though seaweed is very adaptable to any kind of environment, there are only two basic requirements that are necessary for seaweed to sustain. Seaweed can only live in sea water and it needs enough sunlight reaching them so they can carry on the process of photosynthesis.
Like plants on earth use carbon dioxide and sunlight to produce oxygen for human beings to survive, seaweed use carbon dioxide in water and sunlight to produce carbohydrates for the marine life to survive. There would be no marine life if there wasn't any seaweed. Seaweeds can and does survive in all the oceans around world and on earth. It is, however, very important that seaweed have a firm point of attachment, which helps seaweed adapt to their habitat and live.
Like plants on earth use carbon dioxide and sunlight to produce oxygen for human beings to survive, seaweed use carbon dioxide in water and sunlight to produce carbohydrates for the marine life to survive. There would be no marine life if there wasn't any seaweed. Seaweeds can and does survive in all the oceans around world and on earth. It is, however, very important that seaweed have a firm point of attachment, which helps seaweed adapt to their habitat and live.