1 / 24

Trace Metals & Phytoplankton

Trace Metals & Phytoplankton. Gert Vlaming. 24-01-2003. Contents. Introduction Trace metals Importance of phytoplankton Conclusion. Gaia theory. Environment. Life. Trace metals. Fe 3+ Mn 2+ Co 2+ Cu 2+. Ni 2+ Cd 2+ Zn 2+. Trace metals of importance. Complexation field diagram.

chynna
Télécharger la présentation

Trace Metals & Phytoplankton

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Trace Metals & Phytoplankton Gert Vlaming 24-01-2003

  2. Contents • Introduction • Trace metals • Importance of phytoplankton • Conclusion

  3. Gaia theory Environment Life

  4. Trace metals

  5. Fe3+ Mn2+ Co2+ Cu2+ Ni2+ Cd2+ Zn2+ Trace metals of importance

  6. Complexation field diagram Whitfield, 1997

  7. Recycled elements • Low concentrations in the surface layer • Enhanced concentrations in the deeper water • Residence time: intermediate (103 – 105 yrs) • Concentrations: 10-12 – 10-5 M

  8. Concentrations mol/l

  9. Concentrations II • Atlantic ocean receives a greater flux of windborne dust and atmospheric contaminants than the Pacific • Accumulated elements released from the decaying particulate matter • Mn and Co: adsorption onto particles

  10. Biochemical functions And many enzymatic reactions

  11. Availability • > 97% of the total metal in solution is held in strong organic complexes • These complexes are not available for phytoplanktonic uptake The essential trace metals have very low concentrations

  12. Importance of life for trace metal concentrations

  13. Fractionation Broecker & Peng, 1982

  14. Recycling ratio flux circulating within the ecosystem R = flux circulating through the environment R R

  15. Recycling ratio Whitfield, 1997

  16. Recycling ratio II • The inability of phytoplankton to exercise absolute discrimination • Phytoplankton are capable of actively regulating their internal economy • For most essential trace metals the cells are at, or close to, their nutrient limitation levels

  17. Adaptations • Internal • External • Interspecific • Collective There’s a “chemical war” going on ...

  18. Uptake • Diffusion • Transfer of complexes • Capture • Uptake by Michaelis-Menten kinetics

  19. Organic complexation • Cells release organic complexing agents • Beneficial for Fe, Cu en Mn • Enabling large pool of Fe to be maintained • Maintaining concentrations below toxic levels

  20. Conclusions • Availability of trace metals is a significant factor regulating primary production • Phytoplankton is strongly effecting the concentrations of trace metals

  21. Questions

  22. Additional

  23. Evolution of life • Prokaryotic life: 3.5 Ga • Eukaryotic life: 1.5 Ga • Multicellular life: 600 Ma

  24. Start of multicellular life Possibly because: • Lowering of the alkalinity of the oceans • The attainment of an appropriately low global mean temperature • The maintenance of a critical level of dissolved oxygen in the sea • The establishment of the required cocktail of available trace metals

More Related