After catching the marlin, Santiago's victory is short-lived as a group of sharks, attracted by the marlin's blood, begin to attack the carcass. Santiago, determined to protect his catch and prove his worth, fights off the sharks with a harpoon, club, and gaff. The struggle is intense and grueling, with Santiago facing a relentless onslaught of sharks. He kills several, but more keep coming, their jaws snapping and teeth gnashing as they devour the marlin's flesh. Santiago's exhaustion and physical limitations make the battle even more daunting.
Despite his efforts, the sharks continue to return, and Santiago is forced to confront the harsh reality of nature's indifference. The marlin, once a noble and worthy opponent, is now being reduced to a skeleton by the ravenous sharks. Santiago's struggle against the sharks can be seen as a metaphor for humanity's struggle against the forces of nature and the inevitability of decay and death. The sharks represent the destructive power of nature, while Santiago's determination and resilience symbolize humanity's capacity for courage and perseverance in the face of adversity.
Through this struggle, Hemingway highlights Santiago's character and the themes of the novella, including the human condition, the struggle against nature, and the importance of dignity and pride in the face of defeat.