A recent study published in Frontiers in Marine Science demonstrates that increasing ocean acidification, driven by anthropogenic CO₂ emissions, can damage even the teeth of sharks. The publication was first-authored by Maximilian Baum, a biologist at the Heinrich-Heine-Universität Düsseldorf and officer at ElasmOcean.
In the study, naturally shed teeth of blacktip reef sharks (Carcharhinus melanopterus) living in SEA LIFE Oberhausen were incubated for several weeks in seawater with different pH levels—one corresponding to present-day conditions (pH 8.2), and one to the conditions projected for the year 2300 (pH 7.3). The result: significant structural damage in the acidic environment. Cracks, pits, root corrosion, and an altered surface structure were observed in the teeth exposed to the acidification.
Although sharks can regularly replace their teeth, this mechanism may no longer suffice in the future to withstand the increasing pressure. Tooth renewal requires energy—and in combination with other stressors such as overfishing, habitat loss, ocean warming, or plastic pollution, this could further weaken the resilience of many shark species.
The study illustrates how far-reaching the consequences of anthropogenic changes have now become within marine ecosystems. From the smallest snail to the highly specialised predatory tools of apex predators, a wide variety of organisms are affected.
The research project has received significant attention not only in academic circles but also in the media—with coverage by the Süddeutsche Zeitung, BBC, CNN, CBS News, The Guardian, Spiegel, ORF, and many other national and international media outlets. It is crucial to raise public awareness of the vulnerability of sharks.
The study achieved precisely that—which aligns perfectly with the organizational core of ElasmOcean: making relevant science clear and tangible to achieve greater conservation through knowledge.
Source:
Maximilian Baum et al., Simulated ocean acidification affects shark tooth morphology, Heinrich Heine University Düsseldorf (2025), https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1597592/full; DOI: https://doi.org/10.3389/fmars.2025.1597592
