RESPONSE TO NUTRIENT LOAD REDUCTIONS IN A TEMPERATE

ESTUARY

Jason Krumholz, Candace Oviatt, Leslie SmithNEERS

4/13/2012

TALK LAYOUT• Introduction and Background• How have inputs to the Bay changed?• How does this impact the standing stocks?• Do we see changes in biology?• What does it mean/Why do we care?

• 380 km2 surface area-Watershed is ~ 4250 km2

• Dominant circulation pattern is tidally driven

• Watershed is home to 2 million people- very dense.

• 65% of 2003 Nitrogen loading from sewage (Nixon et al. 2008)

• Management intervention • (Brief) Survey Description

NARRAGANSETT BAY

WHY DO WE CARE ABOUT NUTRIENTS?

Lower Nutrients

Less Chlorophyll

Less Settling Organic Matter

Less Benthic O2 Demand

Less Hypoxia

SPATIAL PATTERNS

Average of annual average concentrations (2006-2010)

•DIN/DIP ratio <16:1 is traditionally viewed as a nitrogen limited system.

•On an annual average basis, Narragansett Bay remains nitrogen limited throughout, though this limitation is more severe in the mid and lower bay.

• On shorter time scales, some areas of the Upper Bay do show evidence of P limitation, which may become even more important as N inputs continue to drop.

Average of annual average concentrations (2006-2010)

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010-50

0

50

100

150

200

f(x) = − 2.47445365010626 x + 4953.16409516374R² = 0.0809330686948142

UpgradedNon-Upgraded

Year

N L

oad

(Km

ol/d

)

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 20100

100200

300

400500

600

700800

05101520253035404550Annual Sewage Nutrient Load

TNTP

Year

Load

(103

mol

N/d

)

Laod

(10

3 m

ol P

/d)

DIN PO4 SiO4 TN TP0

10

20

30

40

50

60

79-80 yearly average 06-10 yearly average79-80 summer average 06-10 summer average

Stan

ding

Sto

ck (1

0 6

Mol

es)

**

** ** ** *

*= P<0.05**= P<0.01

IS THERE A CHANGE DRIVEN BY THE REDUCTION?

1975 1980 1985 1990 1995 2000 2005 20100

10

20

30

40

f(x) = − 0.264742647058824 x + 545.608959447415R² = 0.117840885828198

Annual Maxiumum Chlorophyll-a

Chlo

roph

yll-a

(mg/

L)

1975 1980 1985 1990 1995 2000 2005 201001234567

Annual Average Chlorophyll-a

Chlo

roph

yll-a

(mg/

L)LONG TERM CHLOROPHYLL

KOLMOGOROV-SMIRNOV (KS) DISTRIBUTION

SUMMARY• Recent management efforts to reduce nitrogen

loading have resulted in an approximately 1:1 reduction in standing stock.

• Phosphorus loads are already 30-50% less than peak levels. – WWTF & non-point sources– May become more important to biology, especially in upper

bay. • At present, no or minimal biological response to the

loading reductions can be detected.• Future reductions may be large enough to elicit some

biological response

Adapted from Oviatt et al. 1986

Rossie Ennis Leslie Smith Scott NixonAngelo LibertiSteve Granger Ashley BertrandCatherine Walker Brooke Longval Christine ComeauDanielle Dionne Jamie Vaudrey Conor McManusChris Melrose & NOAA/DEM Shuttle TeamFunding Support: NOAA CHRP - Libby Jewett & Alan Lewitus, Project Officers

NOAA Bay Window – Sarah Pike, Project Officer

ReferencesOviatt, C. (1980). Some aspects of water quality in and pollution sources to the Providence River. In R. Pastore, Report for Region 1 EPA. September 1979-September 1980. Boston, MA: United States Environmental Protection Agency.

Oviatt, C., Keller, A., & Reed, L. (2002) Annual primary production in Narragansett Bay with no bay-wide winter-spring phytoplankton bloom. Estuarine Coastal and Shelf Science, 54, 1013-1026.

Nixon, S.W., Buckley, B.A., Granger, S.L., Harris, L.A., Oczkowski, A.J., Fulweiler, R.W., & Cole, L.W. (2008). Nitrogen and Phosphorus Inputs to Narragansett Bay: Past, Present, and Future. In B. Costa-Pierce, & A. Desbonnet, Science for Ecosystem-based Management (pp. 101-175). New York: Springer.

Kremer, J. N., J. M. P. Vaudrey, D. S. Ullman, D. L. Bergondo, N. LaSota, C. Kincaid, D. L. Codiga, and M. J. Brush. 2010. Simulating property exchange in estuarine ecosystem models at ecologically appropriate scales. Ecological Modelling 221:1080-1088.

ACKNOQWLEDGEMENTS

NET EXPORT283

NET EXPORT451

0 5 10 15 20 25 30 35 40 45 500

10

20

30

40

50

60

70

f(x) = − 0.806554042057289 x + 62.9279546689941R² = 0.932688044279039

2006-2010 Linear (2006-2010 )1979-1980

Distance from Fields Point (km)

% A

mm

oniu

m i

n DI

N

P>0.001

0 500 1000 1500

05

1015

2025

Index

data

$DIN

ObsPred

05

1015

2025

obse

rved

23

45

67

8

trend

-20

24

seas

onal

-50

510

15

1980 1985 1990 1995 2000 2005 2010

rand

om

Time

Decomposition of additive time series

0 500 1000 1500

05

1015

2025

Index

data

$DIN

ObsPred

Phase 1: Operational 11/2008 Phase 2: 2009-2013 Phase 3: 2015-2021

General Form: Nd=N0e-kd

0 10 20 30 40 50 60 70 800

20406080

100

f(x) = 0.747886254604885 x + 1.51205676319991R² = 0.707983777256534

Modeled DIN

Observed DIN (mM)

Mod

eled

DIN

(mM

)

0 1 2 3 4 5 6 7 8 9 1002468

10

f(x) = 0.923557107946304 x + 0.041356160581749R² = 0.779526311805201

Modeled PO4

Observed PO4 (mM)

Mod

eled

PO

4 (m

M)

1:1 1:1

0 5 10 15 20 25 30 35 400

200400600800

10001200

DIN residuals by distance

Distance from Fields Point (km)

Squa

red

Resi

dual

0 5 10 15 20 25 30 35 400

5

10

15

20

PO4 residuals by distance

Distance from Fields Point (km)

Squa

red

Resi

dual

0 2 4 6 8 10 1205

10152025303540

Upper Bay Seasonal N/P Ratio2006-20091979-1980Redfield

Month

DIN

/DIP

Rati

o

0 5 10 15 20 25 30 35 40 45 500123456789

Annual Average Downbay N/P ratio

2006-2009

1979-1980

distance from Fields Point (km)

DIN

/DIP

ratio

Sound to Bay Phosphate flux 2006

0 50 100 150 200 250 3000

5000

10000

15000

20000

25000

Series1

Julian Day 2006

Mol

es/d

ay

0 5 10 15 20 25 30 35 40 45 50-1

0

1

2

3

406-09 Annual average TNLinear (06-09 Annual average TN)97-98 Annual average TNLinear (97-98 Annual average TN) 06-09 annual average DINLinear ( 06-09 annual average DIN)

distance from Fields Point (km)

ln o

f con

cent

ratio

n (m

M)

Intercept: NSSlope: P= 0.008

Intercept: P=0.005Slope: NS

Intercept: NSSlope: NS

Discharges to: Flow DIN TN DIP d TPNarragansett Bay Mean St Dev Mean St Dev Mean St Dev Mean St Dev Mean St DevField's Point 1.7x105 4.2x104 4.6x107 7.6x106 6.2x107 9.1x106 1.5x106 9.1x104 3.0x106 5.2x105

Bucklin Point 8.5x104 2.7x104 1.5x107 3.3x106 1.9x107 3.1x106 2.4x106 2.7x105 3.1x106 9.1x105

Newport 3.5x104 1.1x104 1.1x107 2.3x105 4.0x105 2.8x102 5.9x105 1.3x104

East Providence 2.7x104 8.1x103 6.7x106 1.8x106 7.6x106 6.0x105 4.5x105 9.1x101 5.2x105 6.8x103

Bristol 1.4x104 5.1x103 3.9x106 5.2x105 6.1x106 1.5x106 1.2x105 2.1x101 1.8x105 2.0x103

Warren 7.1x103 2.8x103 1.6x106 1.8x104 1.9x106 2.5x104 3.6x104 1.2x101 5.2x104 8.0x102

East Greenwich a 4.1x103 8.5x102 1.3x106 7.2x104 8.7x105 4.3x104 2.9x105 5.8x10-1 4.2x105 4.9x102

Quonset Point 1.8x103 4.7x102 7.3x105 2.2x103 6.8x104 9.3x10-1 1.0x105 3.0x102

Jamestown 1.5x105 9.5x102 1.6x105 1.4x103 1.7x104 1.9x100 2.5x104 2.2x102

Fall River*Blackstone RiverWorcester b 1.1x105 4.2x104 1.7x107 4.8x105 7.1x105

Woonsocket 2.9x104 8.9x103 4.5x106 1.2x106 5.4x106 1.5x106 3.4x105 1.3x105 5.0x105 2.5x105

Smithfield a 7.6x103 1.9x103 1.3x106 2.4x105 1.5x106 3.3x105 1.4x104 1.6x102 2.1x104 1.8x103

Grafton*Millbury*Northbridge*Burrillville 3.2x103 8.4x102 1.3x106 1.2x105 1.4x106 1.2x105 1.6x104 1.3x102 2.4x104 1.8x103

Hopedale*Leicester*Douglas*Upton*Ten Mile RiverAttleboro 1.5x104 4.3x103 7.6x106 4.5x105 1.9x104 1.6x104 2.8x104 2.1x104

North Attleboro c 1.6x104 4.4x103 3.0x106 7.8x105 2.1x104 7.0x103 3.0x104 1.5x104

Pawtuxet RiverCranston a 4.3x104 1.0x104 1.0x107 2.4x106 1.3x107 2.4x106 2.9x105 5.0x103 4.3x105 4.6x104

West Warwick 2.3x104 6.3x103 6.9x106 1.8x106 8.2x106 1.7x106 3.0x105 2.4x104 4.4x105 1.0x105

Warwick 1.9x104 2.0x103 3.8x106 9.4x105 4.7x106 1.0x106 1.3x105 8.0x104 2.0x105 1.3x105

Taunton RiverBrockton*Taunton*Somerset*

* indicates facilities that do not have annual data.a Average and standard deviation values are for 2007-2010 to avoid averaging over upgrade completion.b Average nitrogen and phosphorus load values are 2010 load values as this is the only year of data available after upgrades were completed.c Average and standard deviation values are for 2009-2010 to avoid averaging over upgrade completion.d Average DIP load values for the Field’s Point, Bucklin Point, and East Providence facilities were calculated using the ratio between DIP and TP values from earlier measurements (Nixon, et al., 1995). The ratio between DIP and TP for the remaining facilities was calculated by taking the average of the DIP to TP ratios of the Field’s Point, Bucklin Point, and East Providence facilities. Average DIP load values for the remaining facilities were calculated using this average ratio.

  Flow DIN TN DIP TP

  Mean St Dev Mean St Dev Mean St Dev Mean St Dev Mean St Dev

Blackstone River a 2.574 2.874 66.821 18.452 89.185 40.222 2.341 0.744 5.758 1.641

Pawtuxet River 1.071 1.366 29.047 6.333 41.413 10.272 0.923 0.199 1.949 0.943

Woonasquatucket River 0.225 0.266 3.744 0.603 5.526 1.094 0.052 0.058 0.172 0.069

Moshassuck River 0.115 0.163 1.877 0.310 2.612 0.241 0.006 0.001 0.014 0.002

Ten Mile River 0.320 0.333 10.780 2.226 14.087 1.922 0.095 0.024 0.028 0.000

Taunton River 1.502 1.516 45.340 13.191 81.273 22.824 0.804 0.168 1.290

SOURCES OF NUTRIENTS TO THE BAY

Discharges to: Flow DIN TN DIP d TPNarragansett Bay Mean St Dev Mean St Dev Mean St Dev Mean St Dev Mean St DevField's Point 1.7x105 4.2x104 4.6x107 7.6x106 6.2x107 9.1x106 1.5x106 9.1x104 3.0x106 5.2x105

Bucklin Point 8.5x104 2.7x104 1.5x107 3.3x106 1.9x107 3.1x106 2.4x106 2.7x105 3.1x106 9.1x105

Newport 3.5x104 1.1x104 1.1x107 2.3x105 4.0x105 2.8x102 5.9x105 1.3x104

East Providence 2.7x104 8.1x103 6.7x106 1.8x106 7.6x106 6.0x105 4.5x105 9.1x101 5.2x105 6.8x103

Bristol 1.4x104 5.1x103 3.9x106 5.2x105 6.1x106 1.5x106 1.2x105 2.1x101 1.8x105 2.0x103

Warren 7.1x103 2.8x103 1.6x106 1.8x104 1.9x106 2.5x104 3.6x104 1.2x101 5.2x104 8.0x102

East Greenwich a 4.1x103 8.5x102 1.3x106 7.2x104 8.7x105 4.3x104 2.9x105 5.8x10-1 4.2x105 4.9x102

Quonset Point 1.8x103 4.7x102 7.3x105 2.2x103 6.8x104 9.3x10-1 1.0x105 3.0x102

Jamestown 1.5x105 9.5x102 1.6x105 1.4x103 1.7x104 1.9x100 2.5x104 2.2x102

Fall River*Blackstone RiverWorcester b 1.1x105 4.2x104 1.7x107 4.8x105 7.1x105

Woonsocket 2.9x104 8.9x103 4.5x106 1.2x106 5.4x106 1.5x106 3.4x105 1.3x105 5.0x105 2.5x105

Smithfield a 7.6x103 1.9x103 1.3x106 2.4x105 1.5x106 3.3x105 1.4x104 1.6x102 2.1x104 1.8x103

Grafton*Millbury*Northbridge*Burrillville 3.2x103 8.4x102 1.3x106 1.2x105 1.4x106 1.2x105 1.6x104 1.3x102 2.4x104 1.8x103

Hopedale*Leicester*Douglas*Upton*Ten Mile RiverAttleboro 1.5x104 4.3x103 7.6x106 4.5x105 1.9x104 1.6x104 2.8x104 2.1x104

North Attleboro c 1.6x104 4.4x103 3.0x106 7.8x105 2.1x104 7.0x103 3.0x104 1.5x104

Pawtuxet RiverCranston a 4.3x104 1.0x104 1.0x107 2.4x106 1.3x107 2.4x106 2.9x105 5.0x103 4.3x105 4.6x104

West Warwick 2.3x104 6.3x103 6.9x106 1.8x106 8.2x106 1.7x106 3.0x105 2.4x104 4.4x105 1.0x105

Warwick 1.9x104 2.0x103 3.8x106 9.4x105 4.7x106 1.0x106 1.3x105 8.0x104 2.0x105 1.3x105

Taunton RiverBrockton*Taunton*Somerset*

* indicates facilities that do not have annual data.a Average and standard deviation values are for 2007-2010 to avoid averaging over upgrade completion.b Average nitrogen and phosphorus load values are 2010 load values as this is the only year of data available after upgrades were completed.c Average and standard deviation values are for 2009-2010 to avoid averaging over upgrade completion.d Average DIP load values for the Field’s Point, Bucklin Point, and East Providence facilities were calculated using the ratio between DIP and TP values from earlier measurements (Nixon, et al., 1995). The ratio between DIP and TP for the remaining facilities was calculated by taking the average of the DIP to TP ratios of the Field’s Point, Bucklin Point, and East Providence facilities. Average DIP load values for the remaining facilities were calculated using this average ratio.

  Flow DIN TN DIP TP

  Mean St Dev Mean St Dev Mean St Dev Mean St Dev Mean St Dev

Blackstone River a 2.574 2.874 66.821 18.452 89.185 40.222 2.341 0.744 5.758 1.641

Pawtuxet River 1.071 1.366 29.047 6.333 41.413 10.272 0.923 0.199 1.949 0.943

Woonasquatucket River 0.225 0.266 3.744 0.603 5.526 1.094 0.052 0.058 0.172 0.069

Moshassuck River 0.115 0.163 1.877 0.310 2.612 0.241 0.006 0.001 0.014 0.002

Ten Mile River 0.320 0.333 10.780 2.226 14.087 1.922 0.095 0.024 0.028 0.000

Taunton River 1.502 1.516 45.340 13.191 81.273 22.824 0.804 0.168 1.290

Sound to Bay Phosphate flux 2006

0 50 100 150 200 250 3000

5000

10000

15000

20000

25000

Julian Day 2006

Mol

es/d

ay