Sclerochronology in the Southern Ocean

Abstract

This manuscript aims to provide a comprehensive review of the work done by Antarctic sclerochronology research across different taxa (arthropods, bivalves, brachiopods, bryozoans, cephalopods, hard and soft corals, gastropods, echinoderms and teleost fish), provide an analysis of current challenges in the discipline and start a discussion of what sclerochronology can offer for Antarctic research in future. The Southern Ocean ecosystem remains largely unstudied in part for its remoteness, extreme climate and strong seasonality. This lack of knowledge, some of it even on basic biological information, it is especially worrying due to ongoing climate-driven changes that the Southern Ocean ecosystem is experiencing. Lack of long-term in situ instrumental series has also being a detriment to understand long-term feedbacks between the physical environment and the ecosystem. Sclerochronology, the study of periodic accretional patterns in the hard body structures of living organisms, has contributed to a wide range of Antarctic research disciplines (e.g. paleoclimate reconstructions, population structure analysis, environmental proxies). This review highlights a disparity in research focus by taxa with some groups (e.g. bivalves, teleost fish) attracting most of the research attention, whereas other groups (e.g. gastropod) have attracted much little research attention or in some cases it is almost non-existent (e.g. echinoderms). Some of the long-lived species considered in this review have the potential to provide the much-needed high-resolution eco-environmental proxy data and play an important role in blue carbon storage in the Sothern Ocean. Another issue identified was the lack of cross-validation between analytical techniques.