Hidden Archives of Environmental Change: Application of Mass Spectrometry Methods in Coral Reef Science

Abstract:

Corals feed by filtering plankton from the water as it flows through the reef. During this process, known as filter-feeding, chemical traces are systematically taken up and stored inside the corals’ aragonitic skeletons. As the coral grows, its skeleton forms annual bands akin to the growth rings found in trees. The chemicals stored within these bands can provide insight into the changing conditions of seawater over the entire lifetime of the coral, and serve as useful environmental records. Corals incorporate trace elements that can be precisely registered using high-resolution analytical techniques. These strategies offer high levels of precision to determine the distribution of trace elements along the annual bands of the skeletons, which can serve for both fixed-point time-series and large-scale in ocean observations, as well as for water quality research. This procedure provides insights unobtainable with traditional monitoring studies, as these methods help us reconstruct past climate oscillation episodes and/or pollution events.

Despite that many human activities have been causing ecological degradation and coral reef deterioration, mass spectrometry methods present a practical way for the determination of isotopic signatures in coral skeletons as a tool to monitor marine pollution. In coral reef studies, the isotopic fingerprints can be applied as a tracer system for pollution sources in coastal waters. This approach has great value because we can obtain isotopic data at high-spatial-resolution to create time-resolved records for the investigation of threats that affect the health of coral reefs. The benefits of techno-scientific aspects of new and established isotope applications in coral reef environments hold great promise that may continue to be improved in future studies. Given the current climate crisis, this issue requires accurate measurements to increase our understanding on the impacts that have become more frequent and intense. Enhancing the quality of scientific studies that applies isotopic proxies offers valuable insights into the importance of the upcoming consequences of climate change.