Southern Right Whales flock to the Great Australian Bight each year for a good feed - it may be as simple as that.
New research has found an upwelling of phytoplankton, a veritable smorgasbord of whale food, happens every autumn and early winter and could be a key reason the whales include Australia on their migratory route.
"It's the first time these phytoplankton levels have been uncovered in the Bight and our work also explains the physical mechanisms triggering the autumn blooms," Flinders University School of the Environment Associate Professor Jochen Kaempf says.
"We can't say whether this is a main reason for whales' attraction to the Bight but it very likely is a contributing factor."
Southern Right Whales mainly gather around the head of Bight from mid-May to October, to breed.
The research revealing the ready supply of food disproves the widespread belief that the Bight's deep waters were generally poor for plankton development and not prone to phytoplankton blooms.
The blooms have now been found to return about the same time every year and may explain the relatively high abundance of both forage fish, such as sardines, and higher-level predators including tuna and whales.
Professor Kaempf will present his findings at the Australian Meteorological and Oceanographic Society (AMOS) and Meteorological Society of New Zealand (MSNZ) conference in Canberra this week
