Question

________ in oceans is usually a more complex activity

Answer 1

salt is the answer of this question

Answer 2

fishing in the oceans is usually a very complex activity, you can imagine the high intensity hurricanes normally present in the ocean, it may be very difficult for the fishermen to cop up the situation, this is because the boats used for fishing may be swayed by the hurricane to a point of letting water into the boats and finally making  the boats to capsize.