The marlin is more than a great fish locked in an evenly balanced and protracted battle with an accomplished fisherman. It is also a creature onto whom Santiago projects the same qualities that he possesses, admires, and hopes to pass on: nobility of spirit, greatness in living, faithfulness to one's own identity and ways, endurance, beauty, and dignity. As Santiago and the marlin remain locked in battle for three days, they become intimately connected. Santiago first pities and admires the fish and then empathizes and identifies with it. He recognizes that just as the marlin was born to be a fish, he was born to be a fisherman. They are brothers in the inevitability of their circumstances, locked in the natural cycle of predator and prey.
The marlin's death represents Santiago's greatest victory and the promise of all those intangibles he so desperately hopes for to redeem his individual existence. Yet, like the marlin, Santiago also must inevitably lose and become the victim. After the mako shark's attack, Santiago eats the marlin's flesh to sustain himself, completing the natural cycle in which the great creature passes on something of itself to Santiago. Not only are all creatures predator and prey, but all also nourish one another. Allusions to the crucified Christ that were previously associated with the marlin (images that represent suffering, apparent defeat, and the endurance through which one redeems an individual life within nature's tragic cycle) are transferred to Santiago (as critics such as Philip Young and Arvin Wells have suggested). The marlin's brave and unavailing struggle to save its own life becomes Santiago's brave an unavailing struggle to save the marlin from the scavenger sharks.
The scavenger sharks strip the marlin of all material value, leaving only its skeleton lashed to Santiago's skiff. But before that skeleton ends up as so much garbage to be washed out with the tide, it becomes a mute testimony to Santiago's greatness and the vehicle for those intrinsic values Santiago craves to give his existence meaning and dignity. The fisherman who measures the marlin's skeleton reports that it is 18 feet long — evidence of the largest fish the villagers have ever known to come out of the Gulf. And when Manolin accepts the marlin's spear, he accepts for all time everything that Santiago wishes to bequeath him.