Are the charts of Maury and Townsend good indicators of sperm whale distribution and seasonality?

The charts of Maury (1851) and Townsend (1935) contain a considerable amoun tof information on where and in which season, 19th century Yankee whalers made their kills, especially of sperm whales Physeter macrocephalus. Measures of the total catch of sperm whales from Townsend's charts are a good and easily available source of information on the pre-whaling spatial distribution of sperm whales in the pacific. In contrast, neither seasonal catch nor seasonal catch per unit effort statistics need be correlated with the seasonality of whale abundance. Information on seasonality can only be inferred from these charts with great caution.