Subsistence whale hunting dates back to 400AD (Perrin et al 2009). Large-scale industrialised whaling to provide whale oil commenced in the late nineteenth century. Hunts escalated in the early 20th century and reports to the International Whaling Commission (IWC) show that over two million great whales were killed in hunts in the Southern Ocean between 1925 and 1985 and that unreported ‘pirate’ whaling was also widespread (Clapham & Ivashenko 2009). In 1982, as several whale species neared extinction, the IWC agreed an international moratorium on commercial whaling, which took effect in 1986.