Does Elevated Ammonia-N Negatively Impact Phytoplankton Biomass and - - PowerPoint PPT Presentation

Mary Lou Esparza, Ann Farrell, Doug Craig, Curt Swanson and Bhupinder Dhaliwal

March 8, 2013

Does Elevated Ammonia-N Negatively Impact Phytoplankton Biomass and Community Composition in Freshwater or Brackish Water?

• Phytoplankton biomass, Chl(a), in the SFE has

significantly dropped from the late 1970’s.

• Diatom abundance in the SFE has significantly

dropped from the late 1970’s.

• Cyanobacteria and flagellates abundance has

generally increased from the late 1970’s.

• Phytoplankton biomass, Chl(a), in the SFE has

significantly dropped from the late 1970’s.

• Diatom abundance in the SFE has significantly

dropped from the late 1970’s.

• Cyanobacteria and flagellates abundance has

generally increased from the late 1970’s. Background General Concensus Background General Concensus

Baxter et al. (2010); Solger-Muller et al. (2002); Jassby (2008)

Background Potential causes of the change: Background Potential causes of the change:

• Salinity
• Freshwater flows
• Turbidity/irradiance
• Temperature
• Grazing pressures (clams)
• Inhibitory contaminants (Herbicides)
• Nutrients
• Other unknown factors
• Salinity
• Freshwater flows
• Turbidity/irradiance
• Temperature
• Grazing pressures (clams)
• Inhibitory contaminants (Herbicides)
• Nutrients
• Other unknown factors

Baxter et al. (2010); Cloren and Jassby (2012)

Background Nutrients Background Nutrients Hypotheses:

• Elevated NH4 (>4 µmol) suppresses phytoplankton

NO3 and/or NH4 uptake – eliminating phytoplankton blooms that were regular in the 1970’s

Dugdale et al. (2007) Parker et al. (2012a) Parker et al. (2012b)

• Increased N:P and NH4:NO3 ratios have shifted

phytoplankton composition from diatoms to cynobacteria/flagellates dominance

Glibert (2010) Glibert et al. (2011)

Hypotheses:

• Elevated NH4 (>4 µmol) suppresses phytoplankton

NO3 and/or NH4 uptake – eliminating phytoplankton blooms that were regular in the 1970’s

Dugdale et al. (2007) Parker et al. (2012a) Parker et al. (2012b)

• Increased N:P and NH4:NO3 ratios have shifted

phytoplankton composition from diatoms to cynobacteria/flagellates dominance

Glibert (2010) Glibert et al. (2011)

Background Caution Flags Background Caution Flags 1. Elevated NH4 (>4 µm) does not always inhibit phytoplankton blooms.

• From 1968 – 1979, phytoplankton blooms regularly
• ccurred in the SFE at NH4 concentrations >4 µmol

Ball & Arthur (1979)

• In Delaware Estuary, generally more phytoplankton

biomass, Chl(a), occurs at relatively high NH4 levels compared to SFE

Yoshiyama & Sharp (2006)

1. Elevated NH4 (>4 µm) does not always inhibit phytoplankton blooms.

• From 1968 – 1979, phytoplankton blooms regularly
• ccurred in the SFE at NH4 concentrations >4 µmol

Ball & Arthur (1979)

• In Delaware Estuary, generally more phytoplankton

biomass, Chl(a), occurs at relatively high NH4 levels compared to SFE

Yoshiyama & Sharp (2006)

Background Caution Flags Background Caution Flags 2. Reduced NH4, <4 µmol, offer no reasonable assurance that phytoplankton blooms will occur, even though NO3 is plentiful.

• In 2010, field sampling blooms occurred only on four

sampling events out of 30 when NH4 was <4 µmol in the SFE

Dugdale et al. (2012)

• “At low ammonium concentrations, while some

nitrate uptake rates are high, most are quite low, implying that other factors besides external NH4….”

Dortch, Q. (1990)

2. Reduced NH4, <4 µmol, offer no reasonable assurance that phytoplankton blooms will occur, even though NO3 is plentiful.

• In 2010, field sampling blooms occurred only on four

sampling events out of 30 when NH4 was <4 µmol in the SFE

Dugdale et al. (2012)

• “At low ammonium concentrations, while some

nitrate uptake rates are high, most are quite low, implying that other factors besides external NH4….”

Dortch, Q. (1990)

Background Caution Flags Background Caution Flags 3. Increased N:P and NH4:NO3 ratios do not always mean reduced abundance of diatoms and increased abundance of dinoflagellates and cyanobacteria

McCarthy et al. (2009)

3. Increased N:P and NH4:NO3 ratios do not always mean reduced abundance of diatoms and increased abundance of dinoflagellates and cyanobacteria

McCarthy et al. (2009)

Chlorophyll (a) and NH4 concentrations in Delaware Estuary vs. SFE Chlorophyll (a) and NH4 concentrations in Delaware Estuary vs. SFE

Delaware Estuary*1 SFE2 NH4, µmol 11 6 Chl(a), µg/L 14 4**

1 – 26 year average 2 – 29 year average

*Yoshiyama and Sharp (2006) Table 1 **Jassby (2008) Table 5

• Dr. Richard Dugdale et. al.

Source: River flow and Ammonium discharge determine spring phytoplankton blooms in an urbanized estuary. Revised manuscript for submission to Estuarine, Coastal and Shelf Science August 6, 2012

CCCSD Field Experiment Test the Nutrient Hypotheses CCCSD Field Experiment Test the Nutrient Hypotheses

• Nutrient rich effluent diverted to holding

basin

• After about two days in the basin, the

effluent overflowed into Pacheco Slough

• Samples collected from the overflow,

Pacheco Slough upstream and downstream

• f the overflow
• Nutrient rich effluent diverted to holding

basin

• After about two days in the basin, the

effluent overflowed into Pacheco Slough

• Samples collected from the overflow,

Pacheco Slough upstream and downstream

• f the overflow

Water Quality Characteristics Water Quality Characteristics

Characteristics Concentrations, Mean, Range Concentrations, Mean ± sd n=9 Dissolved oxygen, mg/L 7.5 ± 1.7 ph, units 7.6 ± 0.2 Turbidity, NTU 5.4 ± 1.6 Salinity, ppt 0.5 ± 0 Temperature, °C 23.0 ± 2.3 TSS, ug/L 8 (3 - 17) 14 ± 8 BOD, mg/L 6 (2 - 23) 8 ± 5 Soluable COD, mg/L 45 ± 13 NH4-N, mg/L 26.2 (14 - 30.5) 26.7 ± 1.1 NO3-N, mg/L 0.78 (0.3 - 1.9) 0.28 ± 1.1 NO2-N, mg/L 0.34 (0.4 - 1.4) 0.27 ± 0.19 Total-P, mg/L 1.13 (0.7 - 1.8) 1.14 ± 0.27

318 102 226 85 178 336 71 116 42 148 410 21.7 25.9 23.4 26.5 25.6 24.6 18.9 16.5 16.5 27.3 27.0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 8/2/12 (11:20) 8/23/12 (10:32) 9/5/12 (12:15) 9/11/12 (12:49) 9/14/12 (14:14) 9/18/12 (11:59) 9/27/12 (10:29) 10/3/12 (11:20) 10/5/12 (11:58) 10/9/12 (16:09) 10/11/12 (12:42) Sampling Dates & Times

Chl-a (ug/L) Ammonia-N (mg/L) Ammonia's NO3 uptake inhibitory concentration = 0.056 mg/L Ammonia's NH4 uptake inhibitory concentration = ~0.14 mg/L Healthy Chlorophyll level = (~10 ug/L) Chlorophyll bloom = (>30 ug/L)

Ammonia-N and Chl(a) in Freshwater in relation to NO3 and NH4 uptake inhibitory thresholds and Chl(a) levels considered healthy and blooming. (August 2 – October 11, 2012) Ammonia-N and Chl(a) in Freshwater in relation to NO3 and NH4 uptake inhibitory thresholds and Chl(a) levels considered healthy and blooming. (August 2 – October 11, 2012)

69.0 88.0 51.0 58.0 31.0 49.0 61.0 14.6 0.8 1.5 2.8 2.8 1.2 2.9 2.6 3.6 102.0 16.0 16.5 16.5 18.9 15.1 19.6 18.8 17.8 14.6 1.3 0.8 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 8/23/2012 (10:32) 9/5/2012 (12:15) 9/14/2012 (08:30) 9/14/12 (09:47) 9/18/12 (11:59) 9/21/12 (13:39) 9/27/12 ( 07:57) 10/3/12 (10:45) 10/5/12 (11:23) 10/9/12 (16:09) Chlorophyll (a), ug/L Ammonia-N, mg/L Salinity, ppt 123 111

Ammonia inhibitory concentration = 0.056 mg/L Healthy Chlorophyll level (~10 ug/L) Chlorophyll bloom (>30ug/L)

Ammonia-N and Chl(a) in Brackish Water in relation to NO3 and NH4 uptake inhibitory thresholds and Chl(a) levels considered healthy and blooming. (August 2 – October 11, 2012) Ammonia-N and Chl(a) in Brackish Water in relation to NO3 and NH4 uptake inhibitory thresholds and Chl(a) levels considered healthy and blooming. (August 2 – October 11, 2012)

Freshwater and brackish water Chl(a) data shows that elevated NH4 is not inhibitory to phytoplankton blooms as has been suggested by Dugdale et al. (2007), Dugdale et al. (2012) and Parker et al. (2012a), (2012b). Freshwater and brackish water Chl(a) data shows that elevated NH4 is not inhibitory to phytoplankton blooms as has been suggested by Dugdale et al. (2007), Dugdale et al. (2012) and Parker et al. (2012a), (2012b). Summary

Does elevated NH4 reduce the diatom abundance in brackish water? Does elevated NH4 reduce the diatom abundance in brackish water?

Phytoplankton Composition of Brackish Water Downstream

• f Basin Overflow

(August 2 – October 11, 2012)

70% 13% 13% 3% 1%

Diatom Cryptophytes Chlorophytes Euglanophytes Cyanobacteria Average total cell count/mL = 11,700

Phytoplankton Biomass and Composition in Relation to Ammonia Loads in the Bay-Delta System 2001 - 2010 Phytoplankton Biomass and Composition in Relation to Ammonia Loads in the Bay-Delta System 2001 - 2010

Year Chlorophyll-a1 Diatoms2 Ammonia Loads3 ug/L % tons/month 2001-02 4.7 60 460 2003 4.3 43 ― 2004 4.1 51 ― 2005 3.5 40 550 2006 3.5 39 ― 2007 3.9 52 ― 2008 5.2 22 ― 2009 4.4 68 ― 2010 3.8 73 555

1 - Average for all IEP stations except San Pablo Bay 2 - Average for all IEP stations 3 - Sacramento and Central San loads

Does increasing NH4:NO3 ratio reduce diatom abundance while encouraging dinoflagellates? Does increasing NH4:NO3 ratio reduce diatom abundance while encouraging dinoflagellates?

150 7 1100 11000 6150 11608 6800 11642 11052 4777 9610 ND 1160 22 ND ND ND ND ND 220 1975 - 1996 * 1996 - 2008 9/14/2012 (08:30) 9/14/2012 (09:47) 9/18/2012 9/21/2012 9/27/2012 10/3/2012 10/5/2012 10/9/2012 Diatoms Cyanobacteria N:P ratio 4.4 N:P ratio 8

* Source: CWA,

2012 N:P ratio 16 N:P ratio 49 N:P ratio 42 N:P ratio 48 N:P ratio 41 N:P ratio 38 N:P ratio 58 N:P ratio 59

NH4:NOX (NO3+NO2) ratio vs. Diatom abundance (cells/mL) in Pacheco Slough Downstream of Basin overflow compared to Suisun Bay (D8)

Does increasing NH4:NO3 ratio reduce diatom abundance while encouraging dinoflagellates? Does increasing NH4:NO3 ratio reduce diatom abundance while encouraging dinoflagellates?

55 9610 4777 11052 11642 6800 6150 11600 11000 1100 1986 - 1993 * 2000 - 2006 * 9/14/2012 (08:30) 9/14/2012 (09:47) 9/18/2012 9/21/2012 9/27/2012 10/3/2012 10/5/2012 10/9/2012 NH4:NOX ratio 0.18 NH4:NOX ratio 0.25 NH4:NOX ratio 12 NH4:NOX ratio 20 NH4:NOX ratio 11 NH4:NOX ratio 10 NH4:NOX ratio 15 NH4:NOX ratio 15 NH4:NOX ratio 12 NH4:NOX ratio 12

* Source IEP Data for Station D8

* *

N:P Molar ratio vs. Diatom abundance (cells/mL) in Pacheco Slough Downstream of Basin overflow in relation to Suisun Bay Historic Data

Would ammonia removal assure NO3 uptake and increased phytoplankton biomass? Would ammonia removal assure NO3 uptake and increased phytoplankton biomass?

0.7 3 1 5.7 35 31 34 22 30 39 49 5 0.9 2.5 2.8 2.8 1.5 54 1.7 2.6 1.7 1.8 1.5 2

9/14/2012 9/18/2012 9/21/2012 9/27/2012 10/3/2012 10/5/2012 10/9/2012 10/11/2012

Date of Sampling µmol N Ammonia (µmol) Nitrate (µmol) Chlorophyll (a) (µg/L)

NO3 uptake inhibition threshold, 4 Expected chl(a), µg/L

Nitrate and Ammonia vs. Diatom abundance (cells/mL) in Pacheco Slough Downstream of Basin overflow in relation to Suisun Bay Historic Data

IEP Monitoring Stations

Source: DWR, (2009); (2010)

Station Analyte Median Concentration

• No. of

samples Station Analyte Median Concentration

• No. of

samples NH4, µmol 0.7 12 NH4, µmol 1 12 NOX, µmol 90 12 NOX, µmol 90 12 C10A Chl(a), ug/L 14 12 C10A Chl(a), ug/L 12 12 NH4, µmol 4 12 NH4, µmol 4 12 NOX, µmol 107 12 NOX, µmol 128 12 P8 Chl(a), ug/L 2 12 P8 Chl(a), ug/L 3 12 NH4, µmol 2 12 NH4, µmol 3 12 NOX, µmol 22 12 NOX, µmol 24 12 D19 Chl(a), ug/L 2 12 D19 Chl(a), ug/L 2 12 NH4, µmol 1 12 NH4, µmol 2 12 NOX, µmol 20 12 NOX, µmol 25 12 D28A Chl(a), ug/L 1 12 D28A Chl(a), ug/L 1 12 NH4, µmol 6 12 NH4, µmol 5 12 NOX, µmol 27 12 NOX, µmol 28 12

2009

D7 Chl(a), ug/L 2 12

2010

D7 Chl(a), ug/L 2 12

NH4:NOx (NO3+NO2) and Chl(a) concentrations at selected IEP sampling stations in 2009 and 2010

Source: DWR, (2009); (2010)

DIN:DIP (N:P) and NH4:NOX ratios1 vs. phytoplankton biomass2 and composition3 at selected IEP stations in the Bay-Delta system

Source: DRW, (2009); (2010)

2009

Station

N:P Ratio NH4:NOX Ratio Chl(a) µg/L Diatom Abundance (Annual Avg) % 2010 Station N:P Ratio NH4:NOX Ratio Chl(a) µg/L Diatom Abundance (Annual Avg) % C10A 14.4 0.01 14 68 C10A 15.6 0.01 12 83 P8 28.1 0.04 2 2 P8 27.5 0.03 3 8 D19 9.2 0.09 2 27 D19 14.2 0.12 2 68 D28A 8 0.05 1 22 D28A 14.2 0.08 1 30 D7 9.4 0.22 2 58 D7 9.4 0.17 2 88 C3A 13.3 1.1 2 94 C3A 9.2 1.5 2 87

1 – Annual Median molar ratio values 2 – Annual Median 3 – Annual Average

Conclusions Conclusions 1. High phytoplankton biomass co-exists with elevated Ammonia-N concentrations in freshwater and brackish water. 2. High diatom abundance, cell density and biovolume co-exists with elevated Ammonia-N concentration in brackish water. 3. Elevated Ammonia-N concentrations did not encourage dinoflagellates or cyanobacteria over diatoms in brackish water. 1. High phytoplankton biomass co-exists with elevated Ammonia-N concentrations in freshwater and brackish water. 2. High diatom abundance, cell density and biovolume co-exists with elevated Ammonia-N concentration in brackish water. 3. Elevated Ammonia-N concentrations did not encourage dinoflagellates or cyanobacteria over diatoms in brackish water.

Conclusions Conclusions 4. Removal of anthropogenic ammonia (<4 umol)

• ffers little or no guarantee that NO3 uptake

would take place resulting in increased phytoplankton biomass. 5. Increased N:P ratios were associated with increased abundance of diatoms with no dinoflagellates.

• Reducing N:P ratios may not increase diatoms

abundance over dinoflagellates or blue green algae 6. Increased NO3:NH4 ratios were associated with increased abundance of diatoms

• Increasing NO3:NH4 ratio may not encourage

diatom abundance over dinoflagellates or blue- green algae 4. Removal of anthropogenic ammonia (<4 umol)

• ffers little or no guarantee that NO3 uptake

would take place resulting in increased phytoplankton biomass. 5. Increased N:P ratios were associated with increased abundance of diatoms with no dinoflagellates.

• Reducing N:P ratios may not increase diatoms

abundance over dinoflagellates or blue green algae 6. Increased NO3:NH4 ratios were associated with increased abundance of diatoms

• Increasing NO3:NH4 ratio may not encourage

diatom abundance over dinoflagellates or blue- green algae

Mean Copepod Abundance (September 21, 27 and October 9, 2012) Estimated Count (# m3)

Mean at Downstream (X2) n=3 Mean at Station near Suisun Bay n=3 Salinity, ppt 2.5 9.8 Ammonia-N, mg/L 16.5 7.7 Copepod Nauplii 13066 12356 Cyclopoid copepods Adults 233 46 Copepodid 2026 846 Limnothiona spp Adults 781 3779 Copepodid 919 5087 Eurytemora Adult 7 Copepodid 86 Pseudodiaptomus sp Adult 7 8 Eurytemora/Pseudodiaptomus spp Juvenile 15 9 Acartiella spp Adult 3 Other copepods 147 18

Melvin D. Ball and James F. Arthur:

Source: Ball & Arthur: Planktonic Chlorophyll Dynamics in the Northern San Francisco Bay Delta T.J. Conomos, Editor American Association of Advancement of Science Pacific division, 1979

Source: Water Quality Conditions in the Sacramento – San Joaquin Delta DWR Report 1996