Pacific herring is one of several vital species common to the upwelling zones near continents that feed not only the humans who inhabit those coasts but most of the larger fish and marine mammals with which they share the sea. Pacific herring migrate in large schools and are found from San Diego Bay to the Bering Sea and around to the Japanese archipelago. They have trout-like bodies and grow to 18 inches, though 9 inches is the common size. They live for up to 16 years and spawn many times during their lives. Pacific herring were a staple food and source of oil for preserving other food, lighting lamps, and fertilizing fields. The industrial fisheries arrived in the late 19th century and very nearly wiped them out in three decades. At one time, almost every bay and inlet in southeast Alaska contained a herring plant where the fish were rendered into oil, salted, pickled, and canned for a booming global market. The herring stocks crashed in the late 1920s, and they are no longer harvested commercially except for carefully controlled roe fisheries throughout their range.