GEOTRACES – plenary talk and sessions at ASLO 2021!

There will be very interesting GEOTRACES talks and poster sessions (see list below) at the

2021 Virtual ASLO meeting 

(June 22-27,

Do not miss them!

Plenary Talk:

*Trace metals as agents and tracers in the ocean and climate system

Plenary speaker: Katharina Pahnke

Date: 25 June 2021 – starting at 18h00 UTC (Room 1)

Biographical information: Katharina is professor for marine isotope geochemistry at the University of Oldenburg, Germany. Her research focuses on the input, transport and biogeochemical cycling of trace elements and metal isotopes in the ocean as well as their role as tracers of past ocean conditions and changes. She and her group are particularly interested in rare earth elements and radiogenic isotopes, that act as fingerprints of trace element source regions and transport pathways both in the modern and the past ocean and offer insight into the role of the ocean in Earth’s climate system.


*SS63: Towards a mechanistic understanding of metal-microbe interactions in the Oceans

Date: 24 June 2021 – starting at 12h00 UTC

Martha Gledhill, GEOMAR Helmholtz Center for Ocean Research,
Yeala Shaked, Interuniversity Institute for Marine Sciences & The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem,
Ingrid Obernosterer, Microbial Oceanography Laboratory(LOMIC), CNRS-Sorbonne University,

Trace metals are essential for life, catalysing key cellular reactions which then govern patterns of ocean fertility and biodiversity. Fundamental in this regard are the ways in which ocean microbes acquire essential metals and how biological activity is affected by metal availability. Diverse microbial community members can compete for this scarce resource, and trace-metal related metabolic functions can also be partitioned among taxa and benefit the whole population. Defining these interactions is critical for understanding the relationship between metabolic rates and elemental cycles in the ocean. Developments in this field are being led by advances in analytical chemistry, nanotechnology, molecular biology, and bioinformatics, as well as the expansion of ‘omics’-related observations of in-situ microbial communities, and within the context of high resolution geochemical such as obtained as part the international GEOTRACES program. In this session we invite contributions that bring together insights from these different disciplines to better understand how microbial activity, diversity and ecology is shaped by interactions with trace metals over different space and time scales. By linking across disciplines, there is the potential to develop the mechanistic understanding required to inform the ecological and biogeochemical models we rely on for testing hypotheses and projecting the impacts of ocean change that will result from the impending BioGeoScapes program. We are specifically interested in contributions that address (i) metal uptake and interactions between microbes for metal resources, (ii) how microbes adapt their physiology to metal scarcity and varied supply, and (iii) how trace metals shape microbial activity and diversity in the ocean.

*SS03: Distribution and impacts of ocean nutrient limitation

Date: 24 June 2021 – starting at 12h00 UTC

Thomas Browning, GEOMAR Helmholtz Centre for Ocean Research Kiel,
Mark Moore, University of Southampton,
Erin Bertrand, Dalhousie University,
Alessandro Tagliabue, University of Liverpool,

Nutrient limitation constrains primary production throughout the global ocean and regulates its responses to climate change. A broadscale picture of nutrient limitation in the current ocean has emerged, with nitrogen limitation revailing in the stratified subtropical gyres and iron limitation in open ocean and some coastal upwelling regions. However, new research is rapidly adding important detail to this simple picture. Evidence continues to accumulate for co-limitation between these and other nutrients, including additional trace elements and vitamins. Such (co-)limitations are likely set by nutrient supply and removal mechanisms to and from the surface ocean, phytoplankton elemental stoichiometry, as well as microbial interactions within communities that are simultaneously under the influence of multiple additional abiotic (light, temperature) and biotic (grazing, viral lysis) controls. To understand this complexity, new approaches ranging from advances in ‘-omics’ capabilities, coordinated cruise programmes and autonomous platform observations, through to alternative mathematic constructions of nutrient limited growth rates, are being utilized. Such advances are urgently needed to better understand the drivers and impacts of oceanic nutrient limitation, as well as meeting the needs of testing and improving Earth System Model simulations projecting the impacts of climate change. This session invites contributions utilizing in situ, experimental, and modelling approaches that represent new advances in understanding oceanic nutrient limitation. These could range from those describing the basic distribution and identity of limiting nutrients for diverse microbial groups to understanding the mechanisms, impacts, and future development of nutrient limitation in the ocean.