The previous posters are rank amateurs and deluded armchair fisheries experts.
This salmon was obviously hatched sightless, with no eyes. Yet somehow, miraculously perhaps, it survived to migrate to the sea, mature to adulthood, and return to its natal steam. Tragically, due to its visual impairment, it was unable to find a mate and here it beached itself to die a death of abject dismay and lonliness, its teeth forever bared in a silent curse to its miserable existence and tragic demise.
That is what happened to this salmon.