It can be difficult to distinguish between the different species of salmon found in the waters of Southeast Alaska. Here is a quick guide to make the task a bit easier:
King salmon are the largest species of salmon typically weighing 20-40lbs. They have a blue-gray back with silvery sides. Small, irregular black spots can be found on the back and dorsal fins, and usually on both lobes of the tail. The most important feature to look for is the black mouth with black gums. This distinguishes kings from cohos, which are somewhat similar in appearance.
Spawning kings lose their silvery sheen and take on a maroon or olive brown color.
Coho salmon have a greenish blue back and silvery sides. They have small black spots on the back, dorsal fin, and usually only on the upper lobe of the tail. They have a black mouth with white gums in contrast to the black gums sported by kings. Spawning cohos develop greenish black heads and dark brown to maroon bodies.
Sockeye salmon have a dark bluish black back and silvery sides. They have no distinctive spots at all. Spawning sockeyes have dull green colored heads and brick red to scarlet bodies.
Pink salmon are substantially smaller than the other species of salmon weighing an average of 5-8 lbs. They have very large spots on the back and very large blotches on both tail lobes. Spawning adults take on a dull gray coloration on the back and upper sides and a creamy white color below. Males develop a pronounced hump.
Chum salmon have a dull gray back with yellowish silver sides. They have no distinct spots. A chum's large eye pupil covers nearly its entire eye. Spawning adults develop olive green coloration on the back and maroon sides covered with irregular dull red bars. Males exhibit many large, canine-like teeth.