Santiago is a naturalist. He has been a fisherman for a long time, and he has a strong respect for the birds, the fish, and the sea. On page 19, the author says,
"He was very fond of flying fish as they were his principal friends on the ocean."
When Santiago speaks of the ocean, he says.
"He always thought of the sea as la mar, which is what people call her in Spanish when they love her. "
He forms a bond with the fish he is trying to catch. Since he doesn't have anyone else to talk to, he talks to the fish, to the birds, and to himself.
"Fish," he said, "I love you and respect you very much. But I will kill you dead before this day ends." (pg 54)
In talking to the bird ABOUT the fish, Santiago says,
"Stay at my house if you like, bird." he said. "I am sorry I cannot hoist the sail and take you in with the small breeze that is rising. But I am with a friend." (fish) (pg 55)
Santiago realizes that he is hungry, and he wonders if the fish is getting really hungry too. He says,
"I wish I could feed the fish, he thought. He is my brother. But I must kill him and keep strong to do it." (pg 59)
When Santiago is out in the water, he sees a flight of wild ducks and
"he knew no one was ever alone on the sea" (pg 61)
At night, when he looked into the sky, knowing that he has to get some sleep, he thinks
I am as clear as the stars that are my brothers......They sleep and the moon and the sun sleep and even the ocean sleeps sometimes on certain days ....." (pg 77)
At the end of his battle with the fish, Santiago tells him,
"Never have I seen a greater, or more beautiful, or a calmer or more noble thing than you,brother."
Santiago enjoys everything about nature. He has a great respect for it. He lives in it and is dependent on it for a living and his own life.
The fish which he has to kill is Santiago's friend at the sea. He says to the fish that he loves it, he respects and admires it for its beauty and strength. He says that the fish is his friend and he is sorry that he killed it because the people who will buy it doesn't deserve it.