PHANEROZOIC CHANGES IN THE OCEANS: THE FORAMINIFERAL RECORD

The past relationship between global temperature and levels of biological diversity is key to prognosticate effects of anthropogenic climate warming on biotas. The geological record is punctuated by numerous (abrupt) changes in temperature and acidification. Over the course of the Phanerozoic, changes in temperature have brought major biogeographic shifts in climate zones and ranges of species.

This presentation illustrates the reaction of modern and fossil larger benthic symbiont-bearing foraminifera (LBF) to major perturbations in the ocean systems (temperature and acidification). Larger symbiont-bearing foraminifera have an excellent fossil record, are ubiquitous components of tropical and subtropical biotas and contribute significantly to the carbonate produced in the tropical world's oceans. We have established global biogeographic databases for Palaeozoic, Upper Cretaceous and modern larger foraminifera and compiled occurrence data to analyse their biogeographic and latitudinal distribution in time and space. We will examine range shifts in modern taxa in response to current climate change, compare them to the fossil record and illustrate the potential of Species Distribution Models (SDM) to prognosticate range shifts in warming oceans. The unique fossil record of calcareous LBF will be used as fingerprint to illustrate their reaction to ocean acidification in the past. Ongoing ocean acidification is progressing at rates that exceed models and projections and affects habitats conducive to organisms that incorporate calcium carbonate. The fossil record of larger symbiont-bearing foraminifera provides a unique archive to appraise the impact of decreasing pH and calcite saturation on environments in future oceans.