Cone Snail eating a sand perch

Hyperactive and clumsy are not usually two words to describe the deadly cone snail.

But, expose one to the levels of ocean acidification expected under predicted climate change – an acid trip of sorts – and what you are left with is a highly strung, uncoordinated mess.

That’s what new research published earlier this year in Biology Letters discovered.

Scientists from the ARC Centre of Excellence for Coral Reef Studies at James Cook University studied the cone snail in various settings.

The results of their study reveals the impact that rising carbon dioxide (CO2) levels could have on the ocean food chain.

“We found the carbon dioxide made the cone snails hyperactive,” lead author Dr. Sue-Ann Watson said.

“But despite moving three times faster than normal they caught fewer prey. They meandered around instead of moving by stealth and sneaking up on their prey.”

Cone snail fails to make dinner

Cone snails typically hide in the sand to surprise their enemy. They harpoon their prey using a powerful venom which can also be fatal to humans.

Scientists took cone snails from around Lizard Island, on the Great Barrier Reef, and put them into tanks with a popular cone snail delicacy, jumping snails.

But, only 10 per cent of the cone snails under the influence of elevated CO2 managed to catch dinner.

In comparison, 60 per cent of those kept in tanks under normal conditions successfully preyed on the jumping snails.

The affect on the predator-prey relationship

Previous work by Dr Watson has shown the behaviour of the cone snail’s prey, such as jumping snails, is also altered by rising CO2 levels.

“As the behaviour of species change under these conditions, so too can the relationship between predator and prey. The results of this study could have implications for food chains beyond cone snails and their prey.

“Marine snails and other molluscs are important for the ocean food chain and are also resources for humans.

“If their behaviour changes, there could be a flow-on effect in the food chain – these changes could potentially affect commercially important seafood species.”

What is ocean acidification?

Ocean acidification occurs when the ocean absorbs carbon dioxide from the atmosphere.  The absorption in turn causes chemical changes as the pH of the water decreases.

“We already know that ocean acidification will weaken snails’ shells.  This new research shows it can also affect their energy levels by increasing activity while at the same time decreasing their food intake,” Professor Philip Munday said.

Paper: Watson S-A, Fields JB, Munday PL. 2017 Ocean acidification alters predator behaviour and reduces predation rate. Biology Letters. 20160797.

This article was first published by James Cook University.

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