1 / 16

Lynn Abramson 1* , Cindy Lee 1 , Stuart G. Wakeham 2 , J. Kirk Cochran 1 , and Robert Aller 1

Organic Composition of Particulate Organic Matter: Implications for the Exchange of Material Between Suspended and Sinking Particles. Lynn Abramson 1* , Cindy Lee 1 , Stuart G. Wakeham 2 , J. Kirk Cochran 1 , and Robert Aller 1

cliggett
Download Presentation

Lynn Abramson 1* , Cindy Lee 1 , Stuart G. Wakeham 2 , J. Kirk Cochran 1 , and Robert Aller 1

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. Organic Composition ofParticulate Organic Matter: Implications for the Exchange of Material Between Suspended and Sinking Particles Lynn Abramson1*, Cindy Lee1, Stuart G. Wakeham2, J. Kirk Cochran1, and Robert Aller1 1. Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 2. Skidaway Institute of Oceanography, Savannah, GA *Lynn.Abramson@msrc.sunysb.edu

  2. Organic Matter Composition POM composition reflects: • Source • Alteration • Exchange among pools

  3. Extent of Degradation Surface Slowly-sinking Fast-sinking 200m ? Depth 800m 1500m • Source & alteration can be revealed by biomarkers • Exchange can be revealed by compositional differences among pools of POM (e.g., pools separated by settling velocity)

  4. Methods • MedFlux Project • DYFAMED site, NW Mediterranean Sea • Spring (Mar.-May) & Summer (May-Jul.) 2003 • Sampled with IRS sediment traps & in situ pumps • Analyzed amino acids & pigments by HPLC

  5. Trap Pump Particle Types • “Suspended” Particles: Pumps • small particles (< 70 µm), with very slow settling velocities • “Sinking” Particles: Traps • Time Series mode: collect bulk sinking material at different depths (benchmark approach) • Settling Velocity mode: collect range of settling velocities

  6. Pumps 3/1 3/21 4/10 4/30 5/20 6/9 6/29 7/19 2003 3/1 3/21 4/10 4/30 5/20 6/9 6/29 7/19 2003 Overview of Conditions

  7. Pigment Composition (%) Amino Acid Composition (%) diatom SiO2 CaCO3 Depth (m) deg. deg. FP Composition with Depth:Early Spring 2003 (Mar. 4 – 11) *TR= time series traps; rest are pumps

  8. Pigment Composition (%) Amino Acid Composition (%) diatom SiO2 CaCO3 Depth (m) deg. deg. FP Composition with Depth:Late Spring 2003 (Apr. 30 – May 12) *TR= time series traps; rest are pumps

  9. Pigment Composition (%) Amino Acid Composition (%) diatom SiO2 FP Depth (m) CaCO3 deg. deg. Composition with Depth:Summer 2003 (Jun. 25 – 30) *TR= time series traps; rest are pumps

  10. Pigments Amino Acids diatom SiO2 FP % Composition CaCO3 deg. deg. Settling Velocity (m*d-1) Settling Velocity (m*d-1) Composition with Settling Velocity:Spring 2003 (Mar. 4 – May 12) *P= 200 m pumps; rest are 200 m settling velocity traps

  11. Pigments Amino Acids diatom deg. deg. FP % Composition SiO2 CaCO3 Settling Velocity (m*d-1) Settling Velocity (m*d-1) Composition with Settling Velocity:Summer 2003 (Jun. 25 – 30) *P= 200 m pumps; rest are 200 m settling velocity traps

  12. Early Spring (Mar.) Pumps Late Spring (May) Pumps Summer (Jun.) Pumps Spring (Mar.-May) 200m SV Trap Summer (May-Jun.) 200m SV Trap Numbers represent depths (pumps) or settling velocities (traps) Traps PC 2 (17%) direction of alteration Pumps PC 1 (32.9%) Composition with Settling Velocity *variable loadings scaled up 10x to fit axes

  13. Spring (Mar.-May) 200m SV Trap Summer (May-Jun.) 200m SV Trap Fresh & BCaCO3 Bacterial settling velocity settling velocity PC 2 (26%) PC 2 (20.5%) Bacterial, Fecal Pellets, & BSi BSi, BCaCO3,Fresh, & Fecal Pellets PC 1 (36.7%) PC 1 (41.6%) Composition with Settling Velocity *variable loadings scaled up 10x to fit axes

  14. Conclusions • Spring: compositional differences indicate limited exchange between suspended & sinking POM • “Suspended” (pumps): freshest; bacterial degradation with depth and progression of the season • Slowly-sinking (SV traps): bacterially-reworked material • Fastest-sinking (SV traps): biominerals & fecal pellets • Summer: more similar composition indicates more exchange between suspended & sinking POM • “Suspended” (pumps): freshest; bacterial degradation with depth • Slowly-sinking (SV traps): fresh material, BCaCO3 • Fastest-sinking (SV traps): BSi, fecal pellets, bacterially-reworked material

  15. Future Work • Examine 2005 data • SV traps at more depths (200m, 400m, & 800m) • Incorporate lipids & POC/234Th • Use data to model extent of exchange between particles of different settling velocities

  16. Acknowledgements • Jenni Szlosek & Zhanfei Liu • Michael Peterson, Robert Armstrong, Jianhong Xue, Juan-Carlos Miguel, Scott Fowler, Madeleine Goutz, Christian Tambourini, and all other MedFlux collaborators • NSF Chemical Oceanography Program

More Related