These ship logbooks provide unique information. Everyday an officer of a ship wrote in the logbook the sea and weather conditions and information about marine mammals seen, those chased, and caught. Logbooks exist for more than 500 voyages, 19% of all the voyages ever made to hunt the bowhead whale. (All the hunting of bowheads was done by whaleships out of New Bedford, MA.) Bockstoce and Botkin digitized all the daily records, which provide more than 65,000 days of observation between 1849 and 1915. Over the years, they have published papers based on these data.

And with the growing concern about the decline in Arctic sea ice coverage, measured by modern satellite remote sensing, the logbooks provided an additional insight. Each day, the logbooks record whether the whalers saw and/or were within sea ice. Cooperating with two sea ice experts of the University of Alaska, Andrew R Mahoney and Hajo Eicken, and an expert on some advanced data analysis methods, Robert A. Nisbet, they showed how Arctic sea ice extent in the Bering, Chukchi, and Beaufort seas from 1850 to 1914 compare with modern sea ice extent. In this section of the CSE website, the major original papers about bowheads and sea ice are available.