Going with the floe: Our first kriller project!
The travel diary of a krill may be written in the bacterial hitchhikers on its back – at least that’s what molecular ecologist Dr Laurence Clarke and Masters student Lisa Schellenberg are counting on as the Antarctic Science Foundation funds its inaugural science project.
By studying the DNA of the microscopic stowaways living on Antarctic krill, they will glean new knowledge about how krill populations mix and move around the icy continent.
Molecular ecologist Dr Laurence Clarke says that it’s a question that has puzzled krill scientists for the past forty years: does krill live as one single connected population around Antarctica? Or does it hang out in smaller sub-populations?
“We all have bacteria that live on our skin making up the ‘human microbiome’. In a similar way, Antarctic krill have bacteria living on their exoskeleton,” said Laurence.
“Communities of krill-associated bacteria have been shown to vary between different swarms of krill around Antarctica,” he said.
Previous studies across the Indian sector of the Southern Ocean by Laurence and others have revealed that combinations of bacteria cluster by region and become more distinct with increasing geographical distance. This was the first evidence to suggest that bacteria on krill, and maybe krill themselves, do live in distinct sub-populations.
“This investment from the Antarctic Science Foundation enables us to analyse samples that were collected by the krill fishery in key areas of the South Atlantic, for example near the Western Antarctic Peninsula and South Georgia.
“This project will determine whether the krill in these areas live in separate populations and if so, how much they mix. This will be directly relevant to the sustainable management of the fishery in this area, which aims to protect the iconic Antarctic species we love like penguins, seals and whales,” he said.
Masters student Lisa Schallenberg working in the lab.
Swabbing a krill for bacterial hitchhikers.
What’s the big deal about krill?
Antarctic krill are central to the Antarctic ecosystem. They are thought to have the largest biomass of any single animal species on the planet. These little crustaceans are the main food source for penguins and marine mammals at the top of the food web in the Southern Ocean.
Krill also play an important role in sustaining the base of the Antarctic food web, the microscopic plants known as phytoplankton. They fertilise the ocean on their daily migration up and down through the ocean water column, transferring nutrients from deeper waters to the surface water where the phytoplankton live.
Antarctic krill slow climate change by feeding on phytoplankton themselves! After a meal of these tiny plants, krill produce waste pellets that sink to the deep ocean, contributing to the removal of dissolved carbon dioxide in surface waters, allowing more to diffuse in from the atmosphere.
The health of Southern Ocean ecosystems depends on effective management of the krill fishery. With the results of this project, managers will be better able to take into account the amount of migration between krill populations in different areas. This is important because if the krill fishery, or predators like whales deplete the krill in a particular area, the migration rate between different areas will determine how long it takes for the krill to return.
Learn more about the importance of krill in this short video from the Australian Antarctic Division.
Thank you
Support from the Antarctic Science Foundation’s generous donors have made the funding of our first project possible. If you would like to make a donation, visit our Giving page for more information.
The Foundation’s priority science projects were identified through an Expressions of Interest process and assessed by a science committee of the Board. Scientists interested in working with the Foundation are invited to submit an EOI through our website.