Fears tiny creature with 'important' role has been interrupted by huge ocean problem
Tiny krill are surprisingly efficient at reducing carbon dioxide in the ocean, but this natural process could be interrupted by a flood of plastic.
An important ocean cooling process created by trillions of tiny invertebrates is at risk of being rapidly altered as plastic floods into Antarctica. Krill plays an important role in reducing the amount of carbon dioxide in the water, and this process is increasingly important as temperatures rise.
While the shrimp-like creatures are just 6cm in length, there are an estimated 700 trillion of them. So it's estimated their combined activities could lock away 23 million tonnes of carbon a year.
Krill can reduce carbon in the ocean using a three-step process:
🌱 Firstly, krill eat a lot of phytoplankton, a plant that absorbs carbon dioxide
🦐 Secondly, when krill consume these microscopic organisms the carbon is also ingested
💩 Thirdly, they excrete carbon in their waste and shed it as an exoskeleton as they grow, both of which fall to the sea floor where the gas is stored away as a natural carbon capture mechanism.
Plastic waste risks constipating Antarctic krill
Now researchers from the British Antarctic Survey (BAS) have discovered a rapidly growing problem that could stifle this ancient planet-cooling process. Tiny plastic particles more than 100 times smaller than the width of a human hair have been discovered in Antarctic waters and it’s feared their presence is altering the composition of the krill poo, and preventing it from quickly sinking.
The problem is created because nanoplastic pollutants in the water encourage the growth of bacteria on poo, causing it to rapidly decompose. Fast-degrading krill poo cannot carry as much carbon as it sinks to the deep ocean. It’s believed the presence of nanoplastics could lessen the impact of krill poo on carbon by 27 per cent.
Oceans absorb around 30 per cent of the carbon that's released into the atmosphere by humans, and around 90 per cent of the heat caused by rising emissions. And the role krill plays in helping process the gas is surprisingly important.
🥵 Incredible image reveals little-known reality in northern Australia
🧃Supermarkets busted selling plastic-wrapped produce at discount
Lead author Clara Manno called her team's discovery “huge”.
“Krill are an important part of the Southern Ocean food web and are the diet of penguins, seals and whales. We had already found plastic pollution in Antarctic krill from the Southern Ocean. But for the first time, we have evidence that plastic pollution could be reducing the ability of krill faeces to transport and store carbon in the deep ocean by over a quarter,” she said.
The study was published in the Marine Pollution Bulletin this week.
Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week’s best stories.
