PORTLAND, Maine (AP) — Sharks, the ocean's top predators, depend on their formidable teeth, which regenerate throughout their lives. However, looming changes in ocean chemistry due to human-induced carbon emissions pose a significant threat to these vital tools.
A recent study conducted by German scientists highlights the potential impact of a more acidic ocean on the structure of shark teeth. The researchers linked human activities, particularly the burning of fossil fuels, to rising ocean acidity levels.
The findings indicate that as oceans continue to acidify, sharks’ teeth could become weaker and more prone to damage, potentially affecting their status at the pinnacle of the marine food chain.
Maximilian Baum, the lead author of the study from Heinrich Heine University Düsseldorf, noted that while tooth loss won't happen overnight, this erosion represents another challenge for sharks that are already grappling with threats like overfishing and climate change.
There is a corrosion effect on sharks' teeth, Baum explained, warning that it could impair their ecological dominance. The study was published in the journal Frontiers in Marine Science, aligning with growing conservationist concerns over ocean acidification.
The Gradual Changes Ahead
The research indicates that the acidity of oceans could increase nearly tenfold by 2300. To examine the effects, scientists collected over 600 discarded teeth from blacktip reef sharks in aquariums, exposing them to both current and projected future acidity levels.
Results showed significant damage in teeth subjected to acidic conditions, with observable cracks, holes, and structural degradation.
Despite the concerning findings, sharks may have some resilience against the changing ocean chemistry. Nick Whitney, a marine scientist at the New England Aquarium, noted that shark teeth develop within their mouths, providing a temporary buffer against external environmental changes.
According to Gavin Naylor, director of the Florida Program for Shark Research, while ocean acidification poses a risk, overfishing remains a more pressing threat to many shark populations.
Broader Implications of Acidification
Researchers warn that ocean acidification has far-reaching consequences beyond sharks, threatening shellfish like oysters and clams, which struggle to form shells in more acidic waters. Additionally, fish scales are likely to weaken, introducing uncertainty into the predator-prey dynamics of ocean ecosystems.
In the face of these ongoing threats, Baum underscores the essential role of sharks in the marine ecosystem, emphasizing the importance of their evolutionary success, largely hinging on the effectiveness of their teeth.
