SCOR Working Group 139
Organic Ligands – A Key Control on Trace Metal Biogeochemistry in the Ocean

Co-chairs: Sylvia Sander (New Zealand), Kristen Buck (USA), and Maeve Lohan (UK)

Other Full Members: Kathy Barbeau (USA), Ronald Benner (USA), Martha Gledhill (UK), Katsumi Hirose (Japan), Ivanka Pizeta (Croatia), Alessandro Tagliabue (France), and Rujun Yang (China-Beijing)

Associate Members: Philip Boyd (Australia), Ken Bruland (USA), Parthasarathi Chakraborty (India), Peter Croot (UK), Jay Cullen (Canada), Thorsten Dittmar (Germany), Christine Hassler (Australia), Rick Keil (USA), James Moffett (USA), François Morel (USA), Micha Rijkenberg (Netherlands), Mak Saito (USA). Barbara Sulzenberger (Switzerland), and Stan van den Berg (UK)

Terms of Reference

  1. To inform the Ocean Sciences community of this WG and related objectives via a widely distributed publication in EOS or analogous journal.
  2. To summarize published results on all aspects of metal-binding ligands in the oceans (e.g., distributions, chemical structure, sources, sinks, stability constants), and to contribute to the organic ligand database for use in biogeochemical models and for those working in the field (including results from ongoing GEOTRACES, SOLAS and CLIVAR efforts). The summary will be included in a review paper published after year 2, as well as in the database on the proposed website.
  3. To expand upon the ligand intercalibration programme, initiated by GEOTRACES, to evaluate key analytical issues with currently employed methodologies and determine how to best link ongoing efforts in trace metal and organic geochemistry to assess natural metal-binding ligand.In a recent intercalibration the preservation of samples for Fe and Cu-organic speciation by freezing at -20°C as been found suitable and will enable to make samples taken during GEOTRACES cruises available to interested scientists. A large intercalibration will thus be possible in the future without additional joint cruises or sampling exercises, but could be performed with samples from several ‘normal stations’ of a GEOTRACES leg. Results from intercalibration efforts will be presented in a manual available via download from the proposed WG website.
  4. To identify how best to incorporate published and future data into biogeochemical models.
  5. To debate the nature of sampling strategies and experimental approaches employed in laboratory and field efforts in workshops and meeting discussions that are needed to enhance our understanding of the links between the provenance, fate, distribution, and chemistry and biological functions of these organic metal-binding ligands in the oceans.
  6. To recommend future approaches to ligand biogeochemistry in a designated symposium, including ongoing GEOTRACES field efforts (i.e., regional surveys and process studies), integration of CLE-ACSV and organic geochemistry techniques, and the need for rapid incorporation of this research in biogeochemical models. Such future recommendations will also be included in the aforementioned downloadable manual on the WG website.
  7. To establish a webpage for this SCOR working group, to promote a forum for discussion of ideas and results in form of a blog, soliciting input from the trace metal biogeochemistry, organic geochemistry and modeling communities and provide a platform to propose special sessions on trace metal-binding ligands at international meetings such as Ocean Sciences, AGU and/or EGU.
  8. To produce conclusions resulting from the outcome of the above objectives in the form of a Website, a journal special issue or book, and a report to SCOR.

Approved: September 2011

Financial Sponsors: NSF, SCOR

Meetings and Updates

#1: 25 February 2012, Salt Lake City, Utah, USA (Notes)
#2: 16 February 2013, New Orleans, Louisiana, USA (Notes)
#3: 23 February 2014, Honolulu, Hawaii, USA (Notes)
#4: 7-11 April 2015, Croatia

Group Web site: