Migrating is not enough for modern planktonic foraminifera in a changing ocean.

Rising carbon dioxide emissions are provoking ocean warming and acidification, altering plankton habitats and threatening calcifying organisms, such as the planktonic foraminifera (PF). Whether the PF can cope with these unprecedented rates of environmental change, through lateral migrations and vertical displacements, is unresolved. Here we show, using data collected over the course of a century as FORCIS global census counts, that the PF are displaying evident poleward migratory behaviours, increasing their diversity at mid- to high latitudes and, for some species, descending in the water column.

A solution for constraining past marine Polar Amplification.

Most climate proxies of sea surface temperatures suffer from severe limitations when applied to cold temperatures that characterize Arctic environments. These limitations prevent us from constraining uncertainties for some of the most sensitive climate tipping points that can trigger rapid and dramatic global climate change such as Arctic/Polar Amplification, the disruption of the Atlantic Meridional Overturning Circulation, sea ice loss, and permafrost melting. Here, we present an approach to reconstructing sea surface temperatures globally using paired Mg/Ca - δO recorded in tests of the polar to subpolar planktonic foraminifera Neogloboquadrina pachyderma.

Large-scale culturing of the subpolar foraminifera reveals tolerance to a large range of environmental parameters associated to different life-strategies and an extended lifespan.

The subtropical to subpolar planktic foraminifera is a calcifying marine protist, and one of the dominant foraminiferal species of the Nordic Seas. Previously, the relative abundance and shell geochemistry of fossil have been studied for palaeoceanographic reconstructions. There is however a lack of biological observations on the species and a poor understanding of its ecological tolerances, especially for high latitude genotypes.

Continuous reproduction of planktonic foraminifera in laboratory culture.

Planktonic foraminifera were long considered obligate sexual outbreeders but recent observations have shown that nonspinose species can reproduce by multiple fission. The frequency of multiple fission appears low but the survival rate of the offspring is high and specimens approaching fission can be distinguished. We made use of this observation and established a culturing protocol aimed at enhancing the detection and frequency of fission.

The global genetic diversity of planktonic foraminifera reveals the structure of cryptic speciation in plankton.

The nature and extent of diversity in the plankton has fascinated scientists for over a century. Initially, the discovery of many new species in the remarkably uniform and unstructured pelagic environment appeared to challenge the concept of ecological niches. Later, it became obvious that only a fraction of plankton diversity had been formally described, because plankton assemblages are dominated by understudied eukaryotic lineages with small size that lack clearly distinguishable morphological features.