The company generally prospered through the 1930s as salmon production grew but many Alaska canneries were idled during World War II and never reopened. After the war, salmon runs declined for a variety of reasons including past overfishing, lax management and a general downturn in salmon survival due to a change in long-term climate cycles known as the Pacific decadal oscillation. Many APA canneries were 50 years old and in need of major modernization but CalPack accountants questioned the investment in rebuilding canneries when salmon runs were in decline and consumers' tastes were turning from salmon to more cheap and abundant tuna.