Sharks may be losing deadly teeth to ocean acidification

Sharks can replace their teeth, with news that always develops because they use the current whole. As sharks count on their teeth to catch prey, this is vital for the survival of one of the best predators in the oceans.

But the ability to repel teeth may not be sufficient to ensure that they can withstand the pressures of a warming world where the oceans become more acidic, new research has revealed. Researchers in Germany have examined the teeth of sharks in various ocean acidification scenarios and have shown that more acidic oceans lead to more fragile and lower teeth.

“Shark teeth, although they are composed of highly mineralized phosphates, are always vulnerable to corrosion in future acidification scenarios of the oceans,” said the first author of the Borders in marine science Article, Maximilian Baum, biologist at Heinrich Heine University Dusseldorf (HHU). “These are very developed weapons built to cut the flesh, without resisting oceanic acid. Our results show how vulnerable the most sharp weapons can be.”

Damage from root to crown

Ocean acidification is a process during which the value of the ocean pH continues to decrease, resulting in more acidic waters. He is mainly motivated by the liberation of CO generated by man₂. Currently, the average pH of the world’s oceans is 8.1. In 2300, it should fall to 7.3, which makes it almost 10 times more acidic than it is currently.

For their study, the researchers used these two PH values ​​to examine the effects of more and less acidic waters on the teeth of the Blacktip Reef sharks. The divers collected more than 600 teeth thrown from an aquarium housing the sharks. Sixteen teeth – those that were completely intact and not damaged – were used for PH experience, while 36 additional teeth were used to measure before and after the circumference. The teeth were incubated for eight weeks in separate 20 -liter tanks.

“This study began as a baccalaureate project and has become a publication evaluated by peers. This is an excellent example of the potential for student research,” said the main study, Professor Sebastian Fraune, who heads the HHU zoology and organization Institute. “Curiosity and initiative can trigger a real scientific discovery.”

Compared to teeth incubated at 8.1 pH, the teeth exposed to more acidic waters have been significantly more damaged.

“We have observed visible surface lesions such as cracks and holes, increased corrosion of roots and structural degradation,” said Fraune. The circumference of the teeth was also higher at higher pH levels. The teeth, however, have not really developed, but the surface structure has become more irregular, which led them larger in 2D images. Although an altered dental surface can improve cutting efficiency, it potentially also makes teeth structurally lower and more prone to rupture.

Small damage, great effects

The study only examined the teeth thrown with non -alive mineralized tissue, which means that the repair processes that can occur in living organisms could not be taken into account.

“In living sharks, the situation can be more complex. They could potentially recall or replace damaged teeth faster, but the energy costs of this would probably be higher in acidified waters,” said Fraune.

Blacktip reef sharks must swim your mouth permanently to be able to breathe, so their teeth are constantly exposed to water. If the water is too acidic, the teeth automatically undergo damage, especially if acidification intensifies, the researchers said.

“Even moderate pH drops could affect more sensitive species with slow dental replication circles or have cumulative impacts over time,” said Baum. “Maintaining the ocean pH near the current average of 8.1 could be essential for the physical integrity of the tools of predators.”

In addition, the study focused only on the chemical effects of ocean acidification on non -living tissues. Future studies should examine the changes in the teeth, their chemical structure and mechanical resilience in living sharks, the researchers said. The study shows, however, that microscopic damage could be sufficient to pose a serious problem for animals according to their teeth for survival.

“It is a reminder that climate change has an impact on the waterfall through food networks and whole ecosystems,” concluded Baum.