This lecture is presented by Dr Jessica Ericson, who won a Royal Society of Tasmania Doctoral Award in 2019.
Antarctic krill (Euphausia superba) are fascinating invertebrates with an important role in the Southern Ocean, as the primary prey of Antarctic whales, seals, penguins, fish, squid and seabirds. Krill are lipid rich, making them a particularly nutritious food for their predators. Many of us know what animals eat krill, but what do krill eat and what makes them so nutritious? This PhD research used fatty acids as dietary biomarkers to investigate the diet of krill over consecutive years and seasons, filling knowledge gaps on krill diet, especially in winter. Because krill are so important in the food web, any decreases in krill biomass could result in a major ecological regime shift. Little is known about how climate change will affect krill. As part of this PhD research, the first long-term study (one-year) was carried out to investigate the effects of ocean acidification on the physiology and biochemistry of krill. These novel results, and those from other recent studies will be discussed.