By their sixth year, nearly all females are breeding and producing pups. Males are physiologically able to breed at 3 to 6 years, but they probably do not participate until after 8 to 10 years because of strong territorial competition among the largest males. At birth the sex ratio seems to favor males slightly. Twins occur rarely. In the 1970s, the worldwide population of Steller's sea lions was about 281,800, with the Alaska population estimated at 242,000, including pups.
Seasonal movements occur generally from exposed areas in summer to protected areas in winter.
Feeding occurs from the intertidal zone to the continental shelf, and Steller's sea lions are considered top level consumers. Clothing, boots, and boat coverings were made from skins. The Chinese once used Steller's sea lion whiskers for cleaning opium pipes. Fur farmers used Steller's sea lion meat for fox food along the Alaska coast. Between 1964 and 1972, Steller's sea lion pups were commercially harvested.