The rhythmic rise and fall of ocean water twice in a day is called:

Which organization defines global ocean boundaries and historically standardized limits where the coast of Antarctica meets the surrounding waters?

Consider the following statements regarding aquatic/oceanic zones: A. The abyssal zone receives less than 1% of sunlight. B. The hadal zone lies between 200–2000 meters deep. C. The profundal zone is a freshwater equivalent of the aphotic zone. D. The photic zone extends up to ~200 meters depth. Which of the above statements are correct?