WASHINGTON — They are the ocean’s most famous apex predator.

But something is eating at them – acid.

Rising acid levels in the world’s seas will dissolve sharks’ teeth – that’s according to a new study.

Research suggests ocean pH will drop from 8.1 to 7.3 by 2300, making the water 10 times more acidic than today, according to the IPCC.

So to find out what that means for these fish, scientists collected teeth shed naturally by the sharks at this aquarium in Germany.

They placed them in water with the same pH level currently found in our oceans, and in water with the pH levels expected in 2300.

After eight weeks, they noted much more damage on the teeth placed in the higher acid solution.

“We discovered that oceanic acidification can damage shark teeth and we’ve known for many, many years that it corrodes also the shells of mussels and also coral skeletons, but we discovered that also shark teeth are affected,” says Maximilian Baum, the study’s lead author and a researcher from Heinrich Heine University.

The reason for the projected rise in ocean acid levels? Climate change.

“As humanity, we are bringing a lot of CO2 emissions in our atmosphere and a lot of it goes to the sea in carbonic acid, and this makes the sea more acid,” says Baum.

Sharks are well known for regrowing their teeth.

They are continually replacing them as each set gets worn down by wear and tear.

But this ability might not save them.

“Sharks can replace their teeth, this is one (bit of) good news. But they have to produce new teeth and this could be harder in more acidificated water and we also know that it sometimes takes maybe months or years to use one tooth and to replace it, so one tooth is exposed for a very long time to seawater,” says Baum.

Without their teeth, these ocean hunters will struggle to catch their prey.

But its not just the survival of sharks that could be threatened – the impact will be felt throughout the entire ecosystem.

“The sharks have a key role in marine ecosystems. If sharks are missing we can see top-down effects on all other marine species, so they are very, very important for coral reefs, for seaweed areas, and we need sharks for a healthy ocean and we need a healthy ocean for a healthy planet and a healthy ecosphere,” says Baum.

Damage to the teeth included cracks and holes in the enamel, and corrosion to the roots.

The study was published in the journal ‘Frontiers in Marine Science’.

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