Sharks may face serious challenges in feeding themselves as ocean acidification threatens to erode their teeth, crucial tools for hunting and survival. Shark jaws carry multiple rows of teeth that continuously replace lost or damaged ones, but rapidly acidifying oceans could outpace this natural renewal, leaving predators with impaired feeding ability and potentially destabilizing marine ecosystems.
Ocean acidification results from increased absorption of carbon dioxide, which lowers pH levels. Scientists project that by 2300, oceans could drop from an average pH of 8.1 to 7.3, creating profound implications for marine life. To study the effects, researchers placed 60 naturally shed teeth from blacktip reef sharks in tanks mimicking current and future pH levels. After eight weeks, teeth in the more acidic water showed roughly double the damage, including root corrosion and altered serrations, according to lead author Maximilian Baum of Heinrich Heine University.
The threat of dental stress adds to sharks’ other challenges, such as prey shortages caused by overfishing. Even modest pH drops could disproportionately affect species with fewer teeth or slower replacement rates. Previous studies have also shown acidification damages denticles, the tooth-like scales on shark skin, as well as shells, corals, and mussels.
Baum suggested sharks may adapt by increasing tooth replacement and repair, a view echoed by Lisa Whitenack, a shark tooth expert at Pennsylvania’s Allegheny College. However, she cautioned that further research is needed to determine whether acid-damaged teeth can still function effectively in hunting and feeding. Reducing human-driven CO₂ emissions remains critical to mitigating these risks and preserving shark populations and marine ecosystem stability.
