Why do you think that the author, Ernest Hemingway, has the sharks attack Santiago’s fish?

The sharks are widely read as representations of literary critics, tearing apart the Santiago's (Hemingway's) catch (book). They can also be read as representations of the negative, destructive aspect of the sea and, more generally, human existence. As we have seen, the theme of unity is very important in the novel, but this unity does not only encompass friendly or innocuous aspects of the whole. While he battles against them, the sharks are no less creatures of the sea than the friendly porpoises Santiago encounters earlier in his expedition. This is brought out most strongly in the descriptions of the mako, the first shark Santiago encounters. "He was a very big Mako shark built to swim as fast as the fastest fish in the sea and everything about him was beautiful except his jaws. His back was as blue as the sword fish's and his belly was silver and his hide was smooth and handsome" (100). Indeed, "he was built as a sword fish except for his huge jaws" (100). The mako is not a nasty or brutish beast, but noble in its own way, a predatory marlin. Reflecting on his victory over the mako, Santiago says the shark is "cruel and able and strong and intelligent. But I was more intelligent than he was. Perhaps not... Perhaps I was only better armed" (103).