How does the life cycle of pink salmon reduce the time spent in freshwater?

The pink salmon (Oncorhynchus gorbuscha) minimizes its time in freshwater by restricting its freshwater stage primarily to the spawning migration and the incubation of eggs.1

Unlike other salmon species that may spend months or years in streams or lakes, pink salmon fry migrate to the sea almost immediately after hatching and absorbing their yolk sac. In some instances, this freshwater phase is further reduced because the fish may spawn in intertidal zones at the mouths of streams, which effectively eliminates the freshwater stage of the life cycle altogether. This rapid transition to the marine environment is a distinct life-history strategy compared to other salmonids, such as coho or sockeye salmon, which require significantly longer periods of freshwater residency before migrating seaward.21