Could Ocean Acidification Leave Sharks Toothless? New Study Reveals Threat to These Apex Predators

Sharks without teeth might sound like a nightmare for swimmers, but a new study reveals that ocean acidification could hurt these powerful predators’ most important tools: their teeth.

Shark jaws are lined with several rows of teeth. When one falls out, a new one quickly moves in. However, rising acidity in our oceans is damaging shark teeth and may lead to tooth loss faster than they can be replaced. This could make it harder for sharks to eat and may disrupt entire ocean ecosystems.

Ocean acidification happens when CO2 from the atmosphere is absorbed by seawater, decreasing its pH. By 2300, experts predict the pH of oceans could drop from 8.1 to around 7.3, which would significantly impact many marine species.

To study how acid affects shark teeth, researchers observed 60 teeth from blacktip reef sharks held in tanks simulating current and future ocean conditions. After eight weeks, the teeth in the more acidic tank suffered about double the damage compared to those in the neutral pH tank. The lead author, Maximilian Baum from Heinrich Heine University in Germany, noted that this included increased root damage and changes to the tooth’s serration.

Bad teeth aren’t just a concern on their own; they compound other challenges sharks face, like dwindling prey due to overfishing. A study from the Food and Agriculture Organization (FAO) found that global shark populations have declined by up to 70% over the past 50 years, largely due to fishing pressures.

Experts agree that combating CO2 emissions is essential to slow down acidification in oceans. Past research indicates that acidification not only harms shark teeth but also damages denticles—the tiny, tooth-like scales on their skin.

Some shark species, particularly those with fewer rows of teeth or slower replacement rates, may be at greater risk. Baum emphasized that it is crucial to understand the broader impacts on ocean predators, as similar studies have already highlighted how acidification harms shells and corals.

Despite these concerns, Baum remains hopeful. He believes that sharks might adapt by increasing their tooth replacement rates or enhancing tooth strength. Lisa Whitenack, a shark tooth expert from Allegheny College, echoed Baum’s thoughts. She indicated that while acidification poses a threat, it will be interesting to see how future research assesses whether damaged teeth still function effectively to catch prey.

As awareness grows about the effects of climate change, it’s important for us to keep the conversation going about how oceanic health affects species like sharks and, ultimately, our entire marine ecosystem. Understanding these connections can guide our actions toward a healthier future for both the oceans and the creatures that inhabit them.



Source link