Bottom-up research to understand penguin diets

Cawtron Institute senior scientist Jonathan
Banks at work in Antarctica.
Photo credit: Cawthron Institute

ANTARCTICA - What can penguins' poo reveal about how the birds are affected by climate change and commercial fishing?

Cawthron Institute senior scientist Jonathan Banks, a faecal DNA specialist, is applying his unique expertise to an international research project into the impacts of climate change and commercial fishing on penguins, killer whales and seals - Antarctica’s top predators.

Dr Banks, who has spent the past three weeks in Antarctica as part of a New Zealand Antarctic Research Institute (NZARI) funded project, said, “As fishing pressure is increasing, we need to understand what these species are eating and how fishing activity will affect the top predators in Antarctica."

He is one of nine researchers working on the year-long project, studying the diets of Adelie penguins, killer whales and Weddell seals to help scientists understand the critical food resources needed for their survival. The team’s research will also provide reference points for detecting future changes, and allow for responsible management of the Ross Sea.

While in Antarctica the team visited penguin and seal colonies spread over a 40km area to collect faecal matter. They also ice fished for fish samples that Dr Banks could compare with the faecal DNA.

Working from a small laboratory at Antarctica New Zealand's Scott Base, Dr Banks extracted approximately 5 millilitres, or one teaspoon, of DNA in total from around 50 different animals. The DNA samples were transported back to New Zealand in separate vials each containing about 0.5 millilitres of faecal DNA.

“I’ll match the DNA sequences from the poo with the DNA sequences from the fish samples and then we’ll know what they’re eating,” Dr Bank said.

Scientists from the Smithsonian Institution, University of Tasmania, NIWA, Landcare Research, University of Auckland, Lincoln University and University of Canterbury are all working on the project.

Its principal investigator is Dr Regina Eisert from Gateway Antarctica at the University of Canterbury.

“Climate change and commercial fishing are two potential drivers of change in the Ross Sea, but our ability to predict or manage impacts is limited by lack of information,” Dr Eisert said.

“Antarctic top predators integrate complex changes in the physical and biological conditions affecting their food resources, making them ideal sentinels for the state of the Ross Sea ecosystem."

She said their work will address crucial gaps in understanding of the Ross Sea ecosystem and its vulnerability to climate change and fisheries, and will also challenge ideas of how Ross Sea's top predators depend on krill, silverfish, and toothfish.

It is Dr Banks’ eighth trip to Antarctica. Previously he has studied penguin lice to understand their evolution, and used genetics to identify the faecal bacterial communities of penguins, seals and skuas.

Prior to his trip to Antarctica he was in Edmonton, Canada, researching the genetics of the Pacific oyster virus.

“I was walking to work in minus 25 degrees and was looking forward to my trip to Antarctica so I could warm up in minus 5 degrees!”

Source
Bottom-up research to understand Antarctica predator diets [press release], Cawthron Institute, 10 January 2014, Scoop.co.nz