1. Biological Production Rates in the Southern California Current System David Munro University of Washington 1

2. Acknowledgements Paul Quay, Mark Haught, Johnny Stutsman, and Jackie Leung (UW) Paul Quay, Mark Haught, Johnny Stutsman, and Jackie Leung (UW) Laurie Juranek, Cynthia Peacock (NOAA), Deirdre Lockwood, Hilary Palevsky Laurie Juranek, Cynthia Peacock (NOAA), Deirdre Lockwood, Hilary Palevsky Ralf Goericke, Dave Wolgast, and CalCOFI research associates (SIO) Ralf Goericke, Dave Wolgast, and CalCOFI research associates (SIO) 2

3. Acknowledgements Funding sources Funding sources First year graduate fellowship from the Program on Climate Change First year graduate fellowship from the Program on Climate Change Office of Naval Research (NDSEG) fellowship Office of Naval Research (NDSEG) fellowship NASA WA space grant fellowship NASA WA space grant fellowship National Science Foundation support for sample supplies and analysis National Science Foundation support for sample supplies and analysis 3

4. Primary Production and Carbon Export in the Coastal Ocean Global aquatic PP from satellites ~45-50 Pg C y -1 (Carr et al., 2006) Global aquatic PP from satellites ~45-50 Pg C y -1 (Carr et al., 2006) Based on derived Chl a, PAR, SST, and calibrated with 14 C PP Based on derived Chl a, PAR, SST, and calibrated with 14 C PP Estimates vary by a factor of 2 (Campbell et al., 2002; Carr et al. 2006) Estimates vary by a factor of 2 (Campbell et al., 2002; Carr et al. 2006) ~20% of ocean PP occurs in continental margins (50- 2000 m depth) (Carr et al., 2002; Muller-Karger et al., 2005) ~20% of ocean PP occurs in continental margins (50- 2000 m depth) (Carr et al., 2002; Muller-Karger et al., 2005) 40 to 50% of global C export flux occurs in continental margins (Muller-Karger et al., 2005; Dunne et al. 2007) 40 to 50% of global C export flux occurs in continental margins (Muller-Karger et al., 2005; Dunne et al. 2007) Eastern Boundary Currents (EBC’s) <1% of ocean surface area but ~20% of global fish catch Eastern Boundary Currents (EBC’s) <1% of ocean surface area but ~20% of global fish catch

5. Sea surface chlorophyll 5 From Sarmiento and Gruber

6. Net Primary Production 6 From Sarmiento and Gruber

7. Air-Sea C Flux in the Coastal Ocean Globally, coastal seas may be a small net sink, high variability Globally, coastal seas may be a small net sink, high variability -0.22±0.16 Pg C y -1 (Cai et al. 2006) -0.22±0.16 Pg C y -1 (Cai et al. 2006) Global ocean ~ Global ocean ~ -2.0 Pg C y -1 -2.0 Pg C y -1 High variability, many poorly characterized systems High variability, many poorly characterized systems Table 1 and Fig. from Cai et al. 2006 Table 1 and Fig. from Cai et al. 2006 7

8. Productivity terms GOP – Gross O 2 production; photosynthetic O 2 production via water-splitting reactions in PSII GOP – Gross O 2 production; photosynthetic O 2 production via water-splitting reactions in PSII NCP – Net community production; net production of O 2 or C in surface ocean after demands of autotrophic and heterotrophic communities have been met NCP – Net community production; net production of O 2 or C in surface ocean after demands of autotrophic and heterotrophic communities have been met NPP – Net primary production (Gross C production minus respiration by phytoplankton) NPP – Net primary production (Gross C production minus respiration by phytoplankton) Estimated using 14 C-PP and VGPM Estimated using 14 C-PP and VGPM NCP/GOP ratio – An estimate of the fraction of gross production available for export in terms of O 2. NCP/GOP ratio – An estimate of the fraction of gross production available for export in terms of O 2. NCP/NPP – equivalent to e-ratio or ef-ratio; fraction of NPP in C terms available for export NCP/NPP – equivalent to e-ratio or ef-ratio; fraction of NPP in C terms available for export 8

9. Study Goals I: Spatial and seasonal variability of PP rates Determine variability of PP and NCP and its impact on coastal C system using in situ methods Determine variability of PP and NCP and its impact on coastal C system using in situ methods Gross oxygen production (GOP) Gross oxygen production (GOP) using 17 Δ of dissolved O 2 using 17 Δ of dissolved O 2 Net community production (NCP) Net community production (NCP) NOP = GOP – (Community Resp) NOP = GOP – (Community Resp) using (O 2 /Ar) measured using (O 2 /Ar) measured Export efficiency (NOP/GOP) Export efficiency (NOP/GOP) Comparison to incubation-based 14 C-PP Comparison to incubation-based 14 C-PP Validation of satellite-based PP in the coastal ocean Validation of satellite-based PP in the coastal ocean 9

10. Study Goals II: Variability in C export over the last three decades Estimate NCP using four different approaches Estimate NCP using four different approaches Mixed layer O 2 budget Mixed layer O 2 budget Mixed layer nitrate budget Mixed layer nitrate budget 15 N uptake f-ratios combined with 14 C-PP 15 N uptake f-ratios combined with 14 C-PP Satellite-based (VGPM) x export algorithms Satellite-based (VGPM) x export algorithms Dunne et al. (2007); Laws et al. (2000) Dunne et al. (2007); Laws et al. (2000) O 2 -NCP from biological O 2 saturation based on O 2 /Ar measurements O 2 -NCP from biological O 2 saturation based on O 2 /Ar measurements Evaluate interannual and decadal variability in NCP Evaluate interannual and decadal variability in NCP 10

11. Study Site: CalCOFI Annual Mean Surface Chl a in mg m -3 from Photobiology Group (SIO)  CalCOFI grid coded by region  17  O 2 /Ar Samples collected during 6 cruises 11

12. 14 C PP: why another method? In vitro effects are a big unknown (Marra, 2002) In vitro effects are a big unknown (Marra, 2002) Uncertainty in what it actually measures (Marra, 2002) Uncertainty in what it actually measures (Marra, 2002) Something between GCP and NCP, closest to net primary production (NPP) Something between GCP and NCP, closest to net primary production (NPP) Recycling of labeled C Recycling of labeled C Some labeled C is dissolved (depending on methodology either included/excluded) Some labeled C is dissolved (depending on methodology either included/excluded) Snapshot estimate (6 to 24 hours) Snapshot estimate (6 to 24 hours) Logistical constraints Logistical constraints

13. 17 Δ in situ GOP Method Uses a mixed layer O 2 and O 2 -isotope budget to estimate GOP in the mixed layer Uses a mixed layer O 2 and O 2 -isotope budget to estimate GOP in the mixed layer Luz and Barkan (2000) Luz and Barkan (2000) GOP = K gas * [O 2 ] sat * GOP = K gas * [O 2 ] sat * 17  not sensitive to respiration 17  not sensitive to respiration More terms in the coastal ocean (i.e. coastal upwelling, curl-driven upwelling, horizontal transports) More terms in the coastal ocean (i.e. coastal upwelling, curl-driven upwelling, horizontal transports) Must convert from O 2 to C Must convert from O 2 to C Not based on an incubation Not based on an incubation ( 17 Δdiss – 16) (249 – 17 Δdiss) 13

14. Ocean Range of 17 Δ Values Purely Photosynthetic O 2 249±15 per meg Purely Gas Exchange O 2 16±2 per meg Half Photo + Half Gas Exchange O 2 132 per meg Measuring 17 Δ yields a direct estimate of the proportion of O 2 from air and photosynthesis. 14

15. Locations of 17  measurements to date, from Juranek and Quay (2013) 15

16. O 2 /Ar in situ NCP method NCP estimates (in O 2 terms) are based on mixed layer budgets for [O 2 ] and [Ar] NCP estimates (in O 2 terms) are based on mixed layer budgets for [O 2 ] and [Ar] NCP = K gas * [O 2 ] sat * ( – 1) NCP = K gas * [O 2 ] sat * ( – 1) NCP/GOP a measure of export efficiency from one measurement NCP/GOP a measure of export efficiency from one measurement Does NOT depend on gas exchange (K gas ) Does NOT depend on gas exchange (K gas ) NCP/GOP is comparable to f-ratio NCP/GOP is comparable to f-ratio 2x N/G ~ f-ratio (new production/net primary production) 2x N/G ~ f-ratio (new production/net primary production) (O2/Ar)meas (O2/Ar)sat 16

17. Spatial maps of 17  diss and biological  2 saturation (from O 2 /Ar) Samples collected at up to 50 of 66 standard CalCOFI stations compared to 16 productivity ( 14 C-PP) stations August 17

18. Variability of 17  -GOP and O 2 :Ar-NCP Annual NCP and GOP in mmol O 2 m -2 d -1 18

19. 17  -GOP : 14 C-PP 19 From Juranek and Quay (2013) MBARI (Munro and Quay, unpublished data)

20. Comparison of NCP/GOP Study Location AuthorsNCP/GOP O 2 terms NCP/NPP C terms NCP/NPP Laws et al (2000) CalCOFI – Entire Grid CalCOFI – N. Inshore CalCOFI – Offshore Munro et al. 2012 0.16±.060.20±.060.15±.060.31±.120.39±.120.29±.120.260.380.18 HOTBATS Subarctic N. Pacific Equatorial Pacific Southern Ocean North Atlantic – bloom – annual – annual Quay et al. 2010 Barkan et al. 2009 Juranek et al. 2012 Hendricks et al. 2005 Stanley et al. 2010 Reuer et al. 2007 Hamme et al. 2010 Quay et al. 2012 0.19±.080.13±.05 0.08 - 0.13 0.06±.05 0.35±.130.07±.060.38±.150.25±.10 0.15 - 0.25 0.12±.10 0.68±.25 0.14±.12 0.150.140.350.120.700.500.50  Coastal Ocean NCP/GOP ratio similar to open ocean (unexpected) 20

21. Particle Export Ratio 21 As predicted by the Dunne et al. 2007 algorithm which is a function of chl a and SST From Sarmiento and Gruber

22. POC Export Production 22 From Sarmiento and Gruber

23. Conclusions I 17  -GOP shows seasonality nearshore 17  -GOP shows seasonality nearshore 17  -GOP consistently 5-7x 14 C-PP and 4x VGPM 17  -GOP consistently 5-7x 14 C-PP and 4x VGPM 17  -GOP/ 14 C-PP = 2-3x at MBARI 17  -GOP/ 14 C-PP = 2-3x at MBARI Suggests that CalCOFI 14 C-PP underestimates NPP due to methodological effects in 14 C-PP Suggests that CalCOFI 14 C-PP underestimates NPP due to methodological effects in 14 C-PP Cannot rule out variability in O 2 /C Cannot rule out variability in O 2 /C NCP:GOP ratios close to ratios observed in the open ocean (0.1 to 0.2) NCP:GOP ratios close to ratios observed in the open ocean (0.1 to 0.2) Higher ratios than predicted by export models offshore Higher ratios than predicted by export models offshore 23

24. Variability in NCP at CalCOFI over the last three decades 24

25. Trends in O 2 in the S. Cal. Current %change in O 2 1984-2006 O 2 trends at ~250 m depth From McClatchie et al. 2010 Bograd et al. 2008

26. Methods: Estimating Biological O 2 saturation using O 2 saturation Consistent relationship between biological O 2 saturation and O 2 saturation Consistent relationship between biological O 2 saturation and O 2 saturation Estimated for each region/season Estimated for each region/season O 2 and nitrate budgets constructed: upwelling terms; horizontal advection; time rate of change; NCP O 2 and nitrate budgets constructed: upwelling terms; horizontal advection; time rate of change; NCP 26

27. NCP anomaly calculated by differencing quarterly NCP with long-term mean for month of cruise 27

28. Longterm NCP trends in the South CCS 28 MEI: Multivariate ENSO Index (Wolter and Timlin 1998) PDO: Pacific Decadal Oscillation (Mantua et al. 1997) NPGO: North Pacific Gyre Oscillation (Di Lorenzo et al. 2008)

29. Conclusions II Negative NCP anomalies in response to strong El Niño events (e.g., 1987, 1991-92, 1998) Less signficant NCP response to weak El Niño and La Niña events. Since 2007, positive NCP anomalies based on all NCP estimates (i.e., O 2 :Ar, nitrate budget, 15 N incubations and satellite NPP) NCP trends over the past three decades suggest that export of organic material to depth within the CalCOFI grid not responsible for lower O 2 concentrations at depth observed by Bograd et al. (2008) and McClatchie et al. (2010) NCP trends over the past three decades suggest that export of organic material to depth within the CalCOFI grid not responsible for lower O 2 concentrations at depth observed by Bograd et al. (2008) and McClatchie et al. (2010) 29

30. Questions? 30