A recent study, published in Frontiers in Marine Science, demonstrates that ocean acidification, driven by anthropogenic CO₂ emissions, can damage the teeth of sharks. The publication was lead-authored by Maximilian Baum, biologist at Heinrich-Heine-Universität Düsseldorf and officer at ElasmOcean.
In the study, naturally shed teeth of blacktip reef sharks, currently housed at SEA LIFE Oberhausen, were incubated for several weeks in seawater of varying pH levels: under present-day conditions (pH 8.2) and under conditions projected for the year 2300 (pH 7.3). The results showed significant structural damage in the acidic environment. Teeth exposed to the acidification exhibited cracks, holes, root corrosion, and altered surface structures.
While sharks are capable of regularly replacing their teeth, this mechanism may prove insufficient in the future to withstand the mounting pressures. Tooth regeneration requires energy; combined with further stressors such as overfishing, habitat loss, ocean warming, or plastic pollution, this could further compromise the resilience of many shark species.
The study highlights how deeply the consequences of anthropogenic changes now penetrate marine ecosystems. From the smallest snail to the highly specialised hunting structures of apex predators, a wide range of organisms are affected.
The research project has received considerable 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 numerous other national and international outlets. Sensitising the public to the vulnerability of sharks is of critical importance.
The study achieved precisely that, aligning with the core mission of ElasmOcean: communicating relevant science in an accessible and tangible manner to foster 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
