A new study has found that ocean acidification could erode shark teeth, potentially leaving the apex predators less able to feed and affecting marine ecosystem stability. Sharks naturally grow multiple rows of teeth, with new ones quickly replacing lost or damaged ones, but rising ocean acidity may damage teeth faster than they can be replaced.
Ocean acidification occurs as the oceans absorb carbon dioxide, lowering pH levels. By 2300, projections suggest ocean pH could drop from 8.1 to 7.3, a change that could have “profound implications for marine organisms,” the study said. To test this, researchers placed 60 naturally shed teeth from blacktip reef sharks into artificial seawater tanks with current and projected pH levels. After eight weeks, teeth in the more acidic water suffered roughly twice as much damage, showing increased root corrosion and altered serrations, according to lead author Maximilian Baum of Heinrich Heine University.
Damage to teeth would add to other pressures on sharks, such as prey shortages caused by overfishing. Baum noted that more sensitive shark species—those with fewer rows of teeth or slower replacement rates—could be particularly affected. Previous studies have shown acidification harms shells, corals, and mussels, highlighting that even large predators are at risk.
While there is concern, there is also reason for cautious optimism. Baum suggested sharks might adapt by increasing tooth replacement rates and improving repair, and experts like Lisa Whitenack of Allegheny College note that damaged teeth may still function. Future studies will need to determine whether tooth corrosion significantly impairs sharks’ ability to hunt and feed effectively. Reducing CO₂ emissions remains critical to slowing ocean acidification and safeguarding marine life.
