Habitat use of humpback whales in Godthaabsfjord, West Greenland, with implications for commercial exploitation

Abstract

North Atlantic humpback whales migrate from breeding grounds to high latitude feeding areas to where individuals display large scale site fidelity. In Godthaabsfjord (Greenland), humpback whales are present from early spring to late autumn. To test for small scale site fidelity and occurrence, identification-photographs were collected from May to September 2007 and 2008 and compared with an older catalogue. We found high small scale site fidelity where 40% of the whales present in 2007 were resighted in 2008. The average resight rate from 1992 to 2008 was 30.2%. Individuals did not remain in the fjord the entire season and the time spent in the fjord was highly variable amongst individuals varying between 7–60% of the time from May to September. Individual humpback whales in the presence and absence of boats were tracked with a land-based theodolite to test for effects of whale watching on whale behaviour. Whale watch vessels were shown to significantly increase whale swimming speed, to shorten long dives and diminish the ratio between surfacings and long dives. It is concluded that the same foraging whales use this fjord system year after year, calling for regulation of whale watching and for consideration when discussing reopening the whaling of humpback whales in West Greenland.