In March 2007 we used a novel (for Australia at that time) approach to understand blue whale foraging behaviour in the Bonney Upwelling as part of former BWS Director Margie Morrice’s PhD (awarded in 2013). The BWS team was joined by US blue whale researchers, John Calambokidis and Greg Schorr of Cascadia Research to attach benign suction cups, complete with dive and acoustic loggers, onto individual blue whales.
This project provided new insights into the underwater foraging and feeding behaviour of blue whales in this region, and how they respond to the changing distribution of their prey. One of the unique features of this research was the collection of prey data while following tagged whales. This work contributed to a better understanding of how blue whales detect and then capture their prey in a murky three-dimensional environment. This is essential baseline data in the context of measuring human disturbance and analysis of its effects.
Krill is one of the most important sources of food for many marine predators including blue whales, but remains mysterious in terms of its distribution and life cycles in the Bonney Upwelling. As part of Margie Morrice’s PhD, the team conducted vessel surveys in a fine-scale study area in the heart of the blue whale feeding ground. These surveys combined visual surveys of whales with hydroacoustic and net sampling of krill and temperature profiling of the ocean to look at, amongst other things, what characterises suitable densities of whale food. This work provided insights into the complex variability of krill distribution and highlighted the wonderful ability of blue whales to find their food in a challenging environment.