There are sharks losing teeth

Sharks are seen as The perfect predator being the hunting machine perfected for millions of years in our seas. His most iconic weapon, a mouth full of rows of sharp teeth like blades, has assured them A place at the top of the oceanic food chain. However, an invisible and silent threat This formidable tool could be weakening: The acidification of the oceans.

Sharks placed to the test. A new study published by A team of German researchershas tested the resistance of these teeth in the chemical conditions that are expected in our seas for the year 2300. The results, observed through powerful microscopes, reveal that even the teeth of the sharks are vulnerable, showing obvious signs of corrosion and structural degradation. This could compromise your ability to hunt, and therefore, your survival.

Why the ocean becomes more acidic. Before entering the experiment methodology you have to know what oceanic acidification means. In summary, it is one of the direct effects of the increase in carbon dioxide, and it is that A quarter of the co₂ we emit is absorbed by the oceans. When coming into contact with water there is a reaction that forms carbonic acid that decreases the pH of the water causing it to be much more acidic.

The forecasts are not promising. In this way, to understand how our seas pH will evolve, you just have to observe CO₂ release forecasts for the coming years. In this case, IPCC projections (Intergovernmental panel of climate change) are very worrying.

If emissions continue to the current rhythm, the reality we will face is that the pH of sea water will fall from the current 8.1 to 7.3 in the year 2300. This change, although it may seem small, represents a mass chemical alteration with serious consequences for marine life.

Teeth in the water of the future. To verify the hypothesis, the scientists collected teeth that black tips sharks had naturally lost in the Sealife Aquarium in Oberhausen (Germany) so as not to damage any alive animal. Specifically, there were 16 selected teeth that submerged two controlled environments.

The first one was the control group where the teeth were exposed to a pH of 8.2, that is, the one that is now in the seas. The second group was the experimental where the teeth were exposed to artificially acidified marine water with CO₂ until a pH of 7.3 is achieved. In this way, it was about simulating the conditions to which they will be exposed in 2300.

The microscope verdict. The results They were clear and alarming: while the teeth of the control group remained in good condition, those who were submerged in acidic water showed significant deterioration. The most affecting part was the base of the tooth, known as the root, where the corrosion level was 8.2% instead of the 5.3% suffered by the control group.

The crown, the visible and cutting part of the tooth, also suffered changes with cracks and holes in the outer layer. But the most worrying thing is that the secondary rows of teeth, crucial to tear the meat from the dams, degraded. Interestingly, when measuring the perimeter of the teeth, those of the acid group showed a slight “increase.” This does not mean that they grew, but that their stress became more irregular and rough by corrosion in a clear sign of degradation.

Why imports a damaged shark tooth. A damaged tooth is not just an aesthetic problem, since for a predator like the shark It is a matter of survival. Weak and less sharp teeth mean lower efficiency when hunting. This could force them to spend more energy to feed, affecting their growth and general physical state.

They have not taken into account other factors. It is important to clarify that this study focused on the purely chemical effects on teeth already detached, without taking into account the possible biological repair mechanisms that a living shark could have. In fact, other studies with living sharks They have shown less drastic resultssuggesting that some species could have some compensation capacity.

However, what this investigation demonstrates unequivocally is that the material from which the shark teeth are made, despite its incredible hardness (They contain fluoroapatitaa more acid -resistant mineral than our teeth), is not invulnerable.

Images | Trust “Tru” Katsande

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