PREVIEW

Climate Change May Blunt Jaws' Bite By 'Ruining Sharks' Teeth’. It’s not just humans who have to watch out for acidic drinks - as new evidence shows that the acidifying oceans are ruining sharks’ teeth. Sharks may be able to replace their razor-sharp teeth throughout their lives - but even this remarkable ability might not be enough to protect them from climate change-related dental problems. That’s because scientists in Germany have found that as oceans become more acidic, shark teeth grow weaker and more brittle, raising concerns for one of the seas’ top predators. “Shark teeth, despite being composed of highly mineralised phosphates, are still vulnerable to corrosion under future ocean acidification scenarios,” said biologist Maximilian Baum. “They are highly developed weapons built for cutting flesh, not resisting ocean acid. Our results show just how vulnerable even nature’s sharpest weapons can be.” Ocean acidification occurs when seawater absorbs human-produced carbon dioxide, lowering its pH and making it more acidic. At present, the world’s oceans average a pH of 8.1. By the year 2300, researchers estimate this could fall to 7.3 – nearly ten times more acidic than today. To test what this might mean for sharks, the researchers studied more than 600 discarded teeth collected from Blacktip reef sharks kept in an aquarium. Sixteen intact teeth were used in the experiment, while a further 36 were measured for changes in circumference. The teeth were incubated for eight weeks in 20-litre tanks set to different acidity levels. The results showed clear damage. Teeth exposed to more acidic water developed visible cracks, holes and root corrosion, alongside structural weakening.