The relationship between the humans and the natural world of the sea in The Old Man and the Sea is a mixed relationship, as is the case in real life.
Santiago loves the ocean - the colors, the patterns in the waves, the feel of the salty air. At the same time, he recognizes the power and the potential for danger inherent in that body of water. Santiago feels kinship with some of the animals of the ocean - indeed, he relates closely and with great respect to his great fish.
You are killing me, fish, the old man thought. But you have a right to. Never have I seen a greater, or more beautiful, or a calmer or more noble thing than you, brother.
Of course, he detests the Portuguese man-of-war and the sharks.
Through it all, the old man recognizes his dependence upon the sea for his livelihood. He understands that he has to work hard for what he gets from the ocean, but he also takes pride in his knowledge and his ability to be able to make his living from nature, as a fisherman.