Shark Teeth Are Crumbling As ocean acidity grows, it's eating into their gnashers

Shark Teeth Are Crumbling

As ocean acidity grows, it’s eating into their gnashers

https://nautil.us/shark-teeth-are-crumbling-1237043/?utm_source=firefox-newtab-en-us

By Sara Kiley Watson September 11, 2025


Shark teeth are a marvel of evolution. They are so sharp that many island cultures once used them as weapons and tools to hunt and cut up meat. Unlike human teeth, shark teeth line the mouths of these ocean predators by the dozen, up to 50 rows deep. Baby sharks are born with complete sets so that they can begin hunting from a young age. But these gnashers may be no match for ocean acidity: As climate change gives marine pH a kick, some shark teeth are crumbling.



That’s according to new research published this week in Frontiers in Marine Science. The ocean absorbs around 30 percent of the globe’s carbon emissions, which sets off a chemical reaction—when carbon dioxide dissolves in seawater, it becomes carbonic acid which leaves more hydrogen ions in the sea, lowering the pH.

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Since the beginning of the Industrial Revolution in the mid 18th century, the average acidity of seawater has jumped an estimated 30 percent, with an especially dramatic change between the 1980s and now. Some experts predict that ocean acidity will double or triple by 2100 unless we drastically cut carbon emissions.

This spells a nightmare for sea life, including sharks. Baum first started wondering if increasing ocean acidity could hurt shark teeth after reading a 2019 study demonstrating how their skin denticles are impacted. “That led me to wonder whether oral teeth, especially in species with constant seawater exposure, might show similar vulnerability, because shark teeth are a homologous structure to skin denticles,” he says.


.............Having fewer sharks around is a huge problem for the ocean—as apex predators, they help to regulate the populations of other creatures in their ecosystems. In one example, a decrease in sharks in the Caribbean led to overpopulation of grouper, which then triggered a decline of the parrotfish populations that are responsible for grazing algae from coral reefs—leaving behind too much algae that now blanket some reefs. Another study demonstrated how the loss of sharks off the coast of North Carolina cascaded into a complete scallop fishery collapse. Not to mention, like whales, sharks act as massive carbon sinks when they die and fall to the ocean floor............................

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