What Divers Should Know About Salmon

Spotting salmon often means immersing oneself in transitional waters, from cooler temperate coastal oceans to the freshwater headstreams where these remarkable fish began life. Encountering them typically occurs in these anadromous pathways—rivers, lakes, and coastal waters across the North Atlantic and North Pacific basins. These ray-finned fish are renowned for their precise homing behavior, returning to the exact stream of their birth, a journey largely driven by olfactory memory.

Among the Pacific species, the formidable Chinook salmon stands out as the largest, frequently exceeding 1.8 meters (6 ft) and 14 kilograms (30 lb), with some even larger specimens referred to as "tyee." In contrast, the Pink salmon is the smallest, averaging 1.6 to 1.8 kilograms (3.5 to 4.0 lb). While most adult Pacific salmon prey on small fish, shrimp, and squid, Sockeye salmon uniquely filter plankton through their gill rakers, offering a distinct observation if encountered during feeding.