Pink Salmon Reproduction
Adult Pink Salmon migrate from the sea to fresh water between the months of July to October.
They travel anywhere from 40 miles/64 kilometres up river to as many as 300 miles/480 kilometres.
Pink salmon in their native range have a strict two year life cycle: odd- and even-year populations do not interbreed. Well, almost never. Due to the strict two-year timeline, it is very rare that even and odd numbered years mate. And since all females and most males die after spawning, Pink Salmon have the shortest life of all the fish.
Pink Salmon, like most Pacific Salmon, spawn between late summer and mid fall, between the months of July and October. Only the Masu Salmon spawns in the spring months.
Pink Salmon, as with all Pacific Salmon see the female being responsible for building and defending the nest, known by experienced anglers and biologists as the redd.
While depositing her eggs, one or more males fertilize them as they fall into the nest. Afterwards, the female covers the newly-deposited eggs, again with thrusts of her tail against the gravel at the top of the nest.
The female lays from 1000 to 2000 eggs in several clutches within the nest, often fertilized by different males. Females guard their nests until death, which comes within days of spawning.
Pink Salmon eggs hatch in December, January and February of the following year.
Within a week of emerging from the gravel nest, Pink Salmon fry make their way down the river to the estuary. Here, the Pink Salmon spend only a short amount of time as they get ready to enter the salt water of the ocean.
The eggs hatch from December to February and the juveniles emerge from the gravel during March and April and quickly migrate downstream to estuaries at about one-quarter gram.
The fish achieve sexual maturity in their second year of life.
Returning to Spawn
After about 18 months at sea, pinks return to their natal streams to spawn. Juveniles become ready for swimming to the ocean soon after they hatch and return with chum and sockeye. They are known to hybridize with chum easily. Adults die shortly after spawning.
Most pink salmon mature in 2 years, so odd and even years are basically unrelated. Odd or even year cycles are dominant in some areas, but are about even in others. Cycles also can take turns at dominance.
Pink and Chum Salmon Hybridization
Pink Salmon and chum salmon sometimes mate to form a sterile hybrid known as the Miko Salmon.
Pink salmon are important to commercial fishermen throughout Alaska, Washington and British Columbia. They are not considered to be one of the preferred salmon, but due to their numbers, they form a significant part of the salmon commercial fishery.