Chum salmon (Oncorhynchus keta) are the most widely distributed Pacific Salmon species and can be found throughout Alaska. They range along the east and west coasts of the North Pacific Ocean, from the Mackenzie and Anderson Rivers in Canada to the Lena River in Russia.
Chums are often called dog salmon, but experts disagree about the origin of this nickname. Some believe chums are called dogs because, in the Arctic, Northwestern, and Interior parts of Alaska, chums were and still are traditionally dried and used as a winter food supply for both humans and dogs. Others argue they are called dog salmon because of the enlarged “canine” teeth the males develop during the spawning season.
Chum salmon are the second-largest Pacific Salmon species. Only Chinook (King Salmon) grow bigger. An average adult chum salmon weighs between 8 and 15 lbs. (3.6 to 6.8 kg), but they can grow as large as 45lbs. (20 kg). During their marine phase, chums are dark metallic blue on the back and silver on the sides and belly. Tiny dark specks may be present, but chums do not have large spots like those on Chinook, coho, and pink salmon. The tail of a chum salmon is highly forked, lacks spots, and has silver streaks along the fin rays.
When chums enter fresh water on the return to their spawning streams, males darken to what is often described as a calico pattern. They turn a dark olive brown and have red to purple, wavy, vertical stripes. They also develop hooked jaws called a kype lined with large, sharp teeth. Females turn brown and have a dark, thick, horizontal bar running along the lateral line. Females also develop a hooked jaw with large teeth, but the jaw is less pronounced than it is in males.
There are two, distinct races of chum salmon that spawn at different times. Summer chums spawn in early to mid-summer, and fall chums, as their name suggests, spawn later in the autumn. Chum salmon usually spawn at the mouth or in the lower sections of a stream or river, but in large river systems, they may travel as far as 2000 miles (3219 km) upriver to spawn.
When spawning, a female chum digs a nest in the gravel of the streambed. She then deposits her eggs in the nest while one or more males release sperm to fertilize the eggs. The female may dig more nests upstream from the first nest, depositing her eggs in the nests until her eggs are gone. A group of nests is called a redd, and a female guards her redd until she becomes weak and dies.
Chum salmon eggs hatch after three to four months. The alevin that emerges from the egg remains in the gravel, receiving nutrients from its yolk sac for 60 to 90 days. When it emerges, a chum salmon fry is dark greenish-brown on the back and iridescent green below the lateral line. It also has 8-12 vertical, spaced parr marks on the upper half of its body, not extending below the lateral line.
Fry begin migrating downstream to the ocean within a few days to a few weeks after emergence when they are only one to two inches long. Young chums spend several months near shore before traveling to the open ocean. They stay in the ocean three to four years where they grow to a size of 8 to 15 lbs. (3.6-6.8 kg) or larger. They grow the fastest during their last year in the ocean. Like other Pacific Salmon, chums return to spawn in the stream or river where they were born, and after spawning, they die.
Juvenile chum salmon eat crustaceans, insects, and young herring. Adults feed on copepods, tunicates, mollusks, and fish. When adults return to fresh water to spawn, they stop eating, and their digestive tract deteriorates.
Chum salmon rank second to pink salmon in average annual catch in Alaska’s commercial fishery. Chum-salmon meat is commercially the least valued of the salmon species, and commercial fishermen are paid less or the same for chums as they are for pink salmon. Chum-salmon eggs, though, are the largest and most valuable of any salmon eggs and are sold in Japan as ikura salmon caviar. Chums are not usually targeted by sports anglers because they rarely aggressively attack a lure.
Is a serial killer stalking women on Kodiak Island? My novel, The Fisherman’s Daughter, is available for pre-order!