Maybe "Whaling in early New Zealand", by A W Reed, 1960.

I'm working on it. It is not Robert McNab, The old whaling days: A history of Southern New Zealand from 1830 to 1840. I am awaiting L. S. Rickard, The Whaling Trade in Old New Zealand, 1965. If that isn't it, I'll try for the Reed -- I haven't located it yet. Thanks for the suggestion.