Sharks could struggle to feed effectively in the future due to ocean acidification, potentially disrupting marine ecosystems, a new study warns. Shark jaws carry multiple rows of teeth, with new ones constantly replacing those lost. However, increasingly acidic oceans are damaging teeth faster than they can be replaced, putting sharks at risk of feeding difficulties.
Ocean acidification occurs as carbon dioxide is absorbed by seawater, lowering pH levels. By 2300, oceans could fall from a pH of 8.1 to 7.3, a change with “profound implications for marine organisms,” according to researchers. To study the effect, scientists exposed 60 naturally shed blacktip reef shark teeth to artificial seawater mimicking current and future pH levels. After eight weeks, teeth in more acidic water showed about twice the damage, including root corrosion and altered serration, said lead author Maximilian Baum of Heinrich Heine University.
Sharks already face challenges like prey shortages from overfishing, and dental erosion could exacerbate the problem. Even moderate acidification could affect species with slower tooth replacement or fewer tooth rows. Previous studies have shown similar effects on shells, corals, and mussels, prompting concern that apex predators may not be immune.
Baum remains cautiously optimistic, suggesting sharks could adapt by increasing tooth replacement and repair. Lisa Whitenack, a shark tooth expert not involved in the study, noted that even corroded teeth might remain functional. Future research will determine whether damaged teeth still allow sharks to hunt and feed efficiently.
