Drawing from such unlikely sources as ships logs, tax records, literary sources, and monastery archives, marine scientists are painting a picture of past life in the global ocean. This picture is proving to be a powerful, and necessary, tool in assessing environmental change in the ocean and associated ecosystems, for without it science’s view of these environments is limited to only a short span of history and hamstrung by a narrow perspective. Utilizing these unorthodox sources of information, researchers from the History of Marine Animal Populations project of the Census, are discovering some surprising facts about human impact on the ocean: Prior to whaling pressure arriving in the 1800s, New Zealand’s southern right whale population was roughly 30 times higher than today’s. Prior to the 1800s, the waters of the English Isles were home to orca and blue whales, as well as porpoise, dolphins, and blue and thresher sharks. Written records from as early as the 2nd century CE suggest that the Romans used trawl nets to catch fish. These and other results are soon to be presented in Vancouver, British Columbia, Canada at the Oceans Past II [1] conference (May 26-28, 2009). More information on the History of Marine Animal Populations project and the Ocean’s Past Conference is available in a detailed press release [2] or on the HMAP [3] website.