Search

Applications of fossil shells of planktonic foraminifera to decipher past environmental change and plankton evolution require a robust operational taxonomy. In this respect, extant planktonic foraminifera provide an opportunity for benchmarking the dominantly morphological species concepts and classification of the group by considering ecological, physiological and genetic characters. Although the basic framework of the taxonomy of extant planktonic foraminifera has been stable for half a century, many details have changed, not the least in light of genetic evidence. In this contribution, we review the current taxonomy of living planktonic foraminifera, presenting a comprehensive standard that emerged from the meetings and consultations of the SCOR/IGBP Working Group 138 “Planktonic foraminifera and ocean changes”. We present a comprehensive annotated list of 50 species and subspecies recognized among living planktonic foraminifera and evaluate their generic and suprageneric classification. Asa result, we recommend replacing the commonly used namesGloborotalia menardii by G. cultrata andGloborotalia theyeri by G. eastropacia, recognize Globorotaloides oveyi as a neglected but valid living species, andpropose transferring the three extant species previously assigned to Tenuitella into a separate genus, Tenuitellita. We reviewthe status of types and designate lectotypes for Globoturborotalita rubescens and Globigerinita uvula. We further provide an annotated list of synonyms and other names that have been applied previously to living planktonic foraminifera and outline the reasons for their exclusion. Finally, we provide recommendations on how the presented classification scheme should be used in operational taxonomy for the benefit of producing replicable and interoperable census counts.

Mineral dust plays an important role in the ocean’s carbon cycle through the input of nutrients and metals which potentially fertilise phytoplankton, and by ballasting organic matter from the surface ocean to the sea floor. However, time series and records of open-ocean dust deposition fluxes are sparse. Here, we present a series of Saharan dust collected between 2015 and 2020 by dust-collecting buoys that are monitoring dust in the equatorial North Atlantic Ocean as well as by moored sediment traps at the buoys' positions at ~21°N/21°W and ~11°N/23°W. We present dust-flux data as well as particle-size distribution data, and make a comparison of the dust collected from the atmosphere at the ocean surface with the dust settling through the ocean and intercepted by the submarine sediment traps. See: www.nioz.nl/dust

Particulate inorganic carbon (calcium carbonate mineral) is produced by pelagic calcifying organisms in the upper layers of the open ocean, it sinks to the deep sea, is partly dissolved and partly stored in the geological archive. This phenomenon, known as the carbonate pump, is an important component of the global carbon cycle and exerts a major influence on climate. The amount of carbonate mineral produced depends on the evolutionary and ecological success of calcifying pelagic organisms. The formulation of adequate predictive carbonate pump modules raises the problem that the behaviour of this highly diverse set of organisms needs to be taken into account. To overcome this difficulty, we propose a “model system” approach, whereby a single representative organism, the coccolithophore Emiliania huxleyi , is investigated in detailed interactive experimental and modelling studies. To construct a comprehensive model of the carbonate pump, subsequent research is envisaged on additional representative organisms, but this work is likely to be facilitated by the experience gained with E. huxleyi . The model system approach permits (1) an emphasis on the non-linear character of the fluxes; (2) a focus on the coupling of the carbonate pump with other climatically important phenomena — the organic carbon pump and DMS production; and (3) exploitation of the experimental accessibility of the E. huxleyi system.