TRANSCRIPT
They are some of the smallest animals in the ocean.
But Antarctic krill play an enormous role in keeping the world's carbon emissions on track.
Feeding on phytokplankton that absorb greenhouse gases on the ocean's surface, krill deposit their waste deep in the ocean.
As Rob King, a krill biologist with the Australian Antarctic Division explains, this process is estimated to remove 23 megatonnes of carbon dioxide from the atmosphere each year - the equivalent to taking 5 million cars off the road.
"Four or five hundred million tonnes of krill swim 200 metres up and down the southern ocean. This is an enormous biological pump, a conveyer belt of carbon down into the ocean, it's absolutely critical for maintaining the balance, and pushing carbon into the world's oceans."
Only 6cm in length, their population make up one of the world's largest biomasses, underpinning the entire Antarctic ecosystem.
"Everything from the great whales that have baleen for straining them out of the water, down to penguins who individually catch krill, even a leopard seal which most people associate as just being a voracious predator of penguins and other seals, that gives you some idea of just how important they are to the ecosystem."
Recognising the importance of krill to our planet, last year, the federal government allocated more than 25 million dollars to building a world leading research facility and krill aquarium in Hobart.
This is the Minister for the Environment, Tanya Plibersek.
"Well, Australia for many years has been leading the argument that we need more marine protected areas around Antarctica because we are worried about overfishing of krill and of course we are worried about the impact of climate change on the krill lifecycle. Krill is a building block of life on this planet."
While krill are vital to global Net Zero targets, worth an estimated 23 billion dollars in carbon storage each year, they are also highly sensitive to a changing climate, intrinsically linked to sea ice at every stage of their life cycle.
David Greene from the Institute for Marine and Antarctic Studies explains.
"The Southern Ocean is undergoing incredibly rapid change, we just saw the lowest sea ice extent on record, it's warming at an unprecedented rate, we're seeing changes in productivity in the amount of phytoplankton."
Concerned about declining Antarctic krill populations, a team of researchers led by David Greene have developed a new data tool, mapping the abundance of krill in the Southern Ocean and their distribution in real time.
Some scientists suggest Antarctic krill will lose 30 per cent of their habitat this century.
"We don't know how resilient the population is going to be to those changes, so we really need to know what those impacts might look like, going out into the next few years, going out in the next decade, going out the next 78 years. One of the key aspects of the model would be to understand the competition between predators, krill and fisheries."
The multi-million dollar Antarctic krill fishing industry is regulated by an international convention - the major catch nations being Norway, China, Chile, South Korea and Ukraine.
The Commission for the Conservation of Antarctic Living Resources sets the yearly catch limit and requires observers aboard all krill vessels.
But footage filmed by the Bob Brown Foundation and Sea Shepherd Global, showing krill trawlers amid pods of whales, have raised concerns about the fisheries' sustainable management.
Alistair Allan is an Antarctic campaigner with the Bob Brown Foundation.
He says most krill trawlers target the same foraging grounds as Antarctica's marine life, and is concerned by an increasing demand for krill.
This is largely driven by health supplements, pet food and for feeding farm raised fish.
"It's pretty hard to believe that krill which is the foundation of the Antarctic ecosystem would end up here in this small patch of water in Tasmania but krill is fed to make these salmon grow and turn their flesh pink."
According to the United Nations Food and Agriculture Organisation, aquaculture is the world's fastest-growing food industry.
A supplier of fish feed to some Australian salmon producers has reportedly defended its use of Antarctic krill, citing nutritional value from a natural source of prey.
But conservationists, like Mr Allan, say its not a necessary part of a farmed salmon's diet.
"As this industry increases, and as climate change gets worse in Antarctica, the concern for krill is, if they hold the whole ecosystem together, why are we catching it - we should really be protecting it. The problem is where they fish it and how much they catch."
Sustainable management of the fishery, fundamental to preserving what has been called, 'the powerhouse' of the Southern Ocean.
