Massive ocean krill swarms – hundreds of millions of tons of them – are a keystone of one of the great planetary life cycles.
A new Australian study published in the journal Nature Climate Change called Risk maps for Antarctic krill under projected Southern Ocean acidification, looks at the threshold at which krill – specifically, their eggs – no longer survive acidification levels caused by CO2 emissions. Krill eggs, as it turns out, are more resistant that some other calcifying creatures such as oysters and sea butterflies. Like the sea butterfly, krill shells are critical to the global carbonate cycle, part of which is the deep-sea calcium carbonate sediment formed by the shells of krill – these shells bind carbon and carry it to depths of the ocean.
But even krill have their limits and those are rapidly approaching.
The impact of higher acidification comes with an increase in fishing – krill are industrially harvested for food products, health supplements, and as feed for fish farming.
Researchers for the study estimate that by 2300, unless drastic measures are undertaken to reduce carbon emissions, the world’s krill might be gone. But they state these estimates might be conservative – a tipping point could be reached earlier.
One proposal underway is the creation of a protected Antarctic zone.
What would really help is the same old answer: a move away from a carbon-based fuel economy.
The Guardian article – Antarctic krill face unhappy Hollywood ending if fossil fuel emissions keep rising by Graham Readfearn