Steffen Hetzinger

Abstract Long-term, high-frequency temperature records are critical for evaluating the vulnerability of marine ecosystems to ongoing ocean warming. Commonly used paleoceanographic archives, such as corals and bivalves, face regional and ecological constraints. Rhodoliths, free-living coralline red algal nodules, are established and globally accessible alternatives, yet their complex three-dimensional growth structures hinder the construction of continuous age models.

1 Introduction Over the last 30 years and starting with the work of Dettman and Lohmann (1993); Dettman and Lohmann (1995), innovations in microsampling techniques for stable isotope analysis of freshwater to marine organisms with accretionary carbonate hard parts (e.g., bivalves, gastropods, corals, and fish) have spurred discoveries in fields such as paleoclimatology, paleobiology, and archaeology (special issues Schöne and Surge, 2005; Prendergast et al., 2017 and references therein).