Ammonium, Phytoplankton Productivity and Spring Blooms in San Francisco Bay/Delta

Ammonium, phytoplankton productivity and spring blooms in San Francisco Bay/Delta

Dick Dugdale, Romberg Tiburon Center, SFSU

Thanks to Frances Wilkerson, Alex Parker, Al Marchi, Anke Mueller-Solger, Karen Taberski, Jim Fuller, Sarah Blaser, Christina Buck. Erica Kress

Funding from Outline

• Need primary productivity (i.e. algae) for healthy food web and fish. Low primary productivity is a problem in SFE/Delta. • Nutrients (and light) are required for primary productivity. SFE has abundant nutrients. The conventional wisdom for SFE is that nutrients don’t matter as they are always in excess. • In most estuaries, high nutrients result in bad unhealthy conditions: eutrophication, low oxygen, harmful algal blooms etc. No such problems in SFE at present. • Conventional wisdom is wrong: the kind of DIN (dissolved inorganic nitrogen) matters, nitrate (NO3) or ammonium (NH4). High NH4 affects the amount of primary production and the dominant type of phytoplankton (algae): good (diatoms) or bad (e.g. cyanobacteria or dinoflagellates). • Solutions/Next Steps Primary productivity is the foundation of a healthy estuary Fishery yield directly related to primary production

Lower Hudson: ~800 Chesapeake: ~550 Tampa Bay: 300-600 Narrangansett: ~310 g m-2 yr-1

1976 – 1987

San Francisco Estuary Low- Salinity Zone 1988 - 2002

Adapted from Nixon 1988 by Cloern, Parker and others In SFE since 1987, historical decline of phytoplankton (diatom dominated) blooms, followed by introduction of invasive Corbula and the POD

60 1 - 50 Conversion to secondary treatment (+ NH4) g/L) µ 40

10 Chlorophyll a ( Chlorophyll 0 Chlorophyll, L µg Chlorophyll, 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 75 76 77 78 79 80 81 82 83 84 Pelagic Organism Decline Diatoms: one type of phytoplankton “Workhorses of the Sea” and of Estuaries

•Evolved and adapted to a high nitrate, low ammonium environment

•Can take up all nitrate in 3-5 days (as long as ammonium is low)

May 2010 bloom diatoms in Suisun Melosira sp. Cyclotella sp. Redfield Ratio: In addition to requiring light for an energy source, phytoplankton need the basic nutrients in this ratio

Redfield Ratio is C:N:P = 106:16:1, molar units,

In addition diatoms need Si in about the ratio 1Si:1N

Mean nutrient concentrations in Suisun Bay in spring (Wilkerson et al., 2006) µmol L-1 NO3 27.5 NH4 6.8 PO4 2.7 Si(OH)4 264.6 (lots of silicate) N:P 13:1 not far from Redfield Simplified Aquatic Nitrogen Cycle

Fish-N

Zooplankton-N

Phytoplankton-N nitrogen fixation excretion uptake and excretion assimilation N2 Urea, DON Ammonium denitrification nitrification Nitrite nitrification Sediments Nitrate 1 - l

Suisun Bay g 30 µ

, Suisun Bay l l 20 µ -1 y 15

Chl-a, g L p h 10 o r 5 o

Monthly measurements h l 0 C 1/1/00 1/1/01 1/1/02 1/1/03 M Suisun Bay

µ 16

, 12 m u i 8

µ n made from 2000-2003 NH4, M o 4 m 1 m - 0 h A

1 - l

1/1/00 1/1/01 1/1/02 1/1/03

l 0.3 Kilometers o m

µ 0.2

pNO ,

3 -1 -1 , 0 20 µ T mol L h - 0.1 r t

, 3

1 0 - l O

N N g 1/1/00 1/1/01 1/1/02 1/1/03 ρ

µ 20

, San Pablo Bay T

-1 , l Chl-a, µg L l San Pablo

y 10 h

p 5 o r

o 0 l

Sacramento- h M

C 1/1/00 1/1/01 1/1/02 1/1/03

San Pablo Bay µ 16

San Joaquin , San Pablo Bay 12 m u Delta i 8 n NH , µM o 4

4 m

m 0 1

38ºN - A h

Suisun Bay 1

- 1/1/00 1/1/01 1/1/02 1/1/03 l

0.3 l o

m 0.2 San Pablo Bay

Central Bay µ ,

pNO , T 3 - 0.1 r

-1 -1 t µ , San Francisco Estuary mol L h 3

1 0 O - l

N g ρ 1/1/00 1/1/01 1/1/02 1/1/03

µ 20

, Central CeBayntral Bay T 15 - l l Chl-a, µg L-1 y 10 h

p 5 o r o

l 0 h

C 1/1/00 1/1/01 1/1/02 1/1/03 M 16 122ºW µ Central Bay , 12 m u µ i 8 NH4, M n o 4 m m 1 0 - A h 1 - •Chlorophyll increases occur when NH l 0.4 1/1/00 1/1/01 1/1/02 1/1/03 4 o

pNO3, m 0.3

µ Central Bay

µmol L-1 h-1 , 0.2

is low and results from nitrate uptake T - r

t 0.1 3

by the phytoplankton O 0 N

ρ 1/1/00 1/1/01 1/1/02 1/1/03 2000 2001 2002 2003 Nitrate uptake increases, once ammonium (NH4) is below an inhibitory concentration (~4 µmol L-1)

0.03 1 -

h Suisun , 3 0.02 San Pablo O Central N V

, ln(Y) = -1.28 * ln(X) - 4.26 e r2 = 0.5 k t a p U

a t 0.01 r t i N

0 4 8 12 Ammonium,Ammonium µµMmol L-1 Cloern data for SFE – more algae (chlorophyll: bigger yellow circles) with less ammonium (NH4)

4 µM (µmol L-1) Simplified Estuarine N Cycle

Zooplankton, Phytoplankton Benthic Grazing N N X NO3 NH4

Secondary Rivers and Seas Yield/Sinking Secondary

Advanced Waste Water Treatment Plants

Cutting off phytoplankton access to NO3 reduces potential phytoplankton biomass by 80% Waste water treatment plants throughout the

system supply NH 4 and NO3

80 SJ March August October 60 December

CC CC

(µM) 40 Nitrate 3 EBDA

NO EB SF

14 CC

12 EB

EBDA 10

SF 8 (µM) Ammonium 4 SJ 6 NH

4 4 µM

0 N 6491 3 6 9 13 15 18 21 24 27 30 32 36 s SFE 2005 USGS Station POWTs abbreviations: CC - Central Contra Costa, EB - East Bay MUD, EBDA - EBDA East Bay, SF - County and City of SF (southeast), SJ - San Jose/ Santa Clara WPCP Ammonium loading has increased into Sacramento River (Jassby 2008) along with population Downstream Sacramento River: shift from NO3 dominated to NH4 system (both concentrations and uptake) with low primary productivity (C uptake) downstream of WWTP

1 PO4 CONCNS: NO3, NH4 March 4 60 NO3 NO2 NH4 Urea ) ) -1 -1

3 40

(umol L 4 DIN (umol L (umol DIN PO 2 20

1 0 30 March NH 4 4 UPTAKE 15NO , 15NH and 13C NO 3 4 25 3 C -1 -1 d , d

20 -1 3 -1

15 WWTP 2

Rho N, umol L Rho C, umol L 1 5

0 00

I-80 KEN L37 ISL 655 653 649 US2 US3 US4 US5 US6 US7 TOW OAK GRCRM44 HOD CRS 657B US13

Suisun

Downstream of WWTP, chlorophyll and diatoms decrease; in NO3 dominated systems diatoms do well- upstream and Suisun Bay (March 2009)

Fluoroprobe Data vs Chl a GF/F and Flow Cytometry Data SWC-09-1 March 26, Sacramento River

8 1x104

Green Algae Diatoms Cryptophytes

Chl a GF/F 3 8x10 fluor. particles 1-5µm 6 WWTP fluor. particles 5-50µm ) 1 - 1 l - 3

L 6x10

m *

* g

µ #

( s ] t

4 s n e e c l i m t g r i

3 a p [ 4x10 p Pigments, µg/L

2 2x103

0 0x100 I-80 Tow Oak R44 Hod XCh Isl Rio 655 653 649 US-2 US-3 US-4 -5 -6 US-7 US-13 Suisun Bay Pigments measured by Fluoroprobe, data courtesy of Anke Mueller Solger

SFRWQCB sampling, March through June 2010 March: with high ammonium, low chlorophyll (algae) May: with low ammonium, high chlorophyll

March 24 2010 May 24 2010 Decline in discharge at SRWWTP and increase in flow resulted in declining NH4 concentration

This resulted in a chlorophyll bloom in Suisun Bay in 2010 Urgent need is to develop a 3-D open source model for SFE/Delta for adaptive management purposes designed to accommodate new information; an example from coastal ocean.

Simulation of chlorophyll using CoSiNE Model- Carbon, Silicon, Nitrogen Ecosystem Model 3km ROMS with CoSiNE model- Chai et al. (2002) West US Coast Summary / conclusions / next steps •Need to reverse the low productivity non-diatom regime •Remove ammonium and maybe eventually nitrate (using Anammox?) • Find and eliminate any toxins/herbicides •Construct a modern open source 3-D model of the bay/delta for management purposes.

Possible solutions: Denitrification, conventional or Anammox END

Increasing nitrogen inputs to SF Estuary

Manufactured N now = to natural nitrogen fixation, A 100% perturbation of the Global Nitrogen Cycle

What form is it discharged? Secondary = ammonium (e.g. Sac Regional WWTP) Advanced Secondary = nitrate (Stockton, San Jose)

100,000 population = 1 Ton N/ day effluent Sac Regional now discharges about 15 Tons N/day as ammonium Plans to double output without changing treatment

Sacramento WWTP NO Stockton WWTP NO Sacramento WWTP NH4 Stockton WWTP NH4 3 3 500 90 80

400 70 60 300 50 40 200 30 3 3 4 4 20 NH-N Load (tons/month) NH-N Load (tons/month) 100 NO-NNO-N Load Load (tons/month)(tons/month) 10 0 0 95 96 97 98 99 00 01 02 03 04 05 06 07 95 96 97 98 99 00 01 02 03 04 05 06 07 Year Year Concentration and loading declined substantially between 7 and 14 April 2010 allowing the bloom to develop in Suisun Bay

Concentration NH4 Loading

Delta Flow NH4 at D4 to Suisun Date m3s-1 mmol N m-3 mmol m-2d-1

17-Mar 496.9 10.31 2.61 24-Mar 283.3 6.97 1.01 7-Apr 616.9 9.66 3.04 14-Apr 633.5 5.5 1.77 26-Apr 765.3 5.18 2.02 12-May 617.3 4.43 1.39 24-May 639.7 3.56 1.16 16-Jun 595.5 4.29 1.30 21-Jun 280.9 2.69 0.38 mean 1.63 sd 0.82 Implications for the nearshore: estuary/ocean interactions Nitrate, uM Ammonium, uM 25 38.10 38.10 Point Reyes Point Reyes 5 38.00 20 38.00

4 37.90 37.90 15 SF Bay SF Bay 37.80 37.80 3 10 37.70 37.70 2

5 37.60 37.60 1

37.50 37.50 Nitrate Ammonium -123.10 -122.80 -122.50 -122.20 -123.10 -122.80 -122.50 -122.20

upwelling Chl, ug/L SF outflow, 38.1 buoyant plume Point Reyes 12 38.0

A 9 37.9 SF Bay B 37.8 C 6

37.7 D

3 37.6

37.5 Chlorophyll

-123.1 -122.8 -122.5 -122.2 Carbon fixation is greater when growth is on NO3 vs NH4

Carbon fixation (rho C) vs NO3 or NH4 (rho N) uptake in enclosures in the Delaware Estuary (from Parker, 2004) Cellular transformations of nitrogen

NRT = nitrate transporter AMT = ammonium transporter NAR = nitrate reductase GS = glutamine synthestase NIR = nitrite reductase