In the late 19th century, the U.S. Fish Commission conducted numerous interviews with fishermen throughout the northeast U.S. including cod and mackerel fishermen from New York, New England and Nova Scotia. Most fishermen interviewed in the 1890s by the commission were over 50 years of age and recollected changes in the marine environment during their lifetimes. These interviews, or oral histories, are an excellent source for observations of Gulf of Maine fisheries. They provide first-hand accounts and observations of fish behavior and fishing activity on specific fishing grounds such as Stellwagen Bank. Most interviewees discuss the migratory patterns and behaviors of mackerel on the east coast. In addition, the fishermen offer descriptions of fish and catch sizes as well as theories for the decline in cod and mackerel in the 19th century.