SPERM WHALERS OFF THE GALAPAGOS-ISLANDS AND IN THE WESTERN NORTH PACIFIC, 1830-1850 - IDEAL FREE WHALERS

Temporal and spatial patterns of American whaling for sperm whales around the Galapagos Islands during the period 1830-1850 were examined using data from logbooks of 68 voyages and compared with results from a similar study in the western North Pacific. These whalers frequently exchanged information, had no legal restrictions, and were trying to maximize their oil yields per unit time. Thus they might have been expected to exploit different whaling grounds approximately as predicted by the ideal free distribution. In all areas examined, rates of sighting and catching whales declined during the study period. Sighting and catch rates and oil yields per whaling day were similar close to the Galapagos Islands where effort was high, and further away where it was lower. But sighting rates were lower, and catch rates and oil yields per whale were higher during the same time period in the western North Pacific. During the period 1830-1835, oil yield per whaling day was higher in the western North Pacific, but whalers continued to work off the Galapagos in violation of the ideal free distribution, perhaps because of imperfections in the information available to them. From 1835-1850, oil yields per whaling day were similar off the Galapagos and in the western North Pacific.