Research shows Antarctic krill scared off by smell of penguin poo in ocean

New research shows krill go berserk in the ocean from the scent of one particular species’ number two. Why this is important for ocean conservation.

Krill specimen in blue water Please Credit: Brett Wilks/AAD -If used on social media please tag the Australian Antarctic Division @AusAntarctic, #AusAntarctic

New research led by a University of Tasmania (UTAS) researcher has revealed that one particular smelly substance can trigger the survival instincts in microscopic krill – with the research potentially able to predict the species’ survival.

Researchers from the UTAS and Georgia Institute of Technology, USA, wanted to build on earlier research done in 2016 about krill’s behaviour around food sources and instead see their reaction to predators.

A new tool has been created to shed light on the mysterious lives of Antarctic krill. Picture: Peter Harmsen/Australian Antarctic Division

Poo, or guano, from Adelie penguins was collected and fed into man-made water channels against seawater with algae, or both algae and guano.

Almost 99 per cent of the Adelie penguin’s diet is krill, with an adult Adélie eating up to 1.6kg of it per day.

This led leading experts to hypothesise their poo may affect krill’s behaviour.

With light and water temperatures made to mimic the Southern Ocean environment, in the water channels, lead author of the research UTAS’ Dr Nicole Hellessey said krills were tested four times at varying water flow velocity with Adelie poo in the water, algae and poo or just algae.

An Adelie penguin colony in East Antarctica, with the red in the picture the Adelie guano. Picture: David Killick

“We found that the krill tried to avoid being near the penguin poo by ‘zigzagging’ in the water, unlike their typical straight swim,” she said.

“We don’t know what chemical is in the poo that they detect but they try to get away from the area of poo and school or clump together as part of their survival instinct.”

A second experiment also detected that krill reduced their rate of eating algae by 64 per cent when penguin poo was in the water.

Dr Hellessey said she had been “spitballing the idea of poo” in order to gather more knowledge of what impacts krill populations and movement in the ocean.

“Guano can wash off on land and can ‘bloom’ in certain spots of Antarctica,” she said.

“Understanding more about krill’s behaviour lets us know where we put Marine-protected environments.

An Adelie penguin with its chicks in East Antarctica. Picture: David Killick

“Looking at different concentrations and other species of animals in future studies and how they make krill behave, or how other chemicals in water or ocean acidification from climate change are changing how krill react could help us to find ways to assist the population numbers of krill.

“Any changes to krill’s behaviour could have major impacts on the future Southern Ocean, as Antarctic krill are a keystone species in this ecosystem.”

Originally published as Research shows Antarctic krill scared off by smell of penguin poo in ocean