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Tidal Marshes of Barnegat Bay: Nutrient History and Ecosystem Services
Dr. David Velinsky
Patrick Center for Environmental Research The Academy of Natural Sciences of Drexel University & Department Head, Biodiversity Earth and Environmental Science December 2016
Collaborators:
Tracy Quirk2, Chris Sommerfield3, Jeff Cornwell4, Ashley Smyth5 and Mike Owens4 2Department of Oceanography and Coastal Sciences, Louisiana State University 3School of Marine Science & Policy, University of Delaware 4Center for Environmental Science, University of Maryland‐Horn Point 5presently at Kansas Biological Survey, University of Kansas
Drs. Marina Potopova and Elizabeth Watson both at Academy of Natural Sciences and Drexel University; Dept. of Biodiversity, Earth and Environmental Science
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Outline
• Climate and Coastal Wetlands • Tidal wetlands of Barnegat Bay • Processes in tidal wetlands • Sediment history and burial • Denitrification in wetlands • Mass Balance • Summary
Wetlands Research at the Academy of Natural Sciences 1965 ‐ Dr. Ruth Patrick in 1965 showed that wetlands can remove nutrients and looked at the extent of wetlands in the Delaware Estuary 1996 –Dr. David Velinsky revisited earlier study and modeled oxygen dynamics in Delaware Estuary: tidal freshwater region 1998‐2002 –Dr. Jeff Ashley explored how PCBs and other contaminants cycle in a urban tidal marsh and accumulate in fish tissue 2007‐2012 –Drs. David Velinsky and Jeff Ashley studied the sediment accumulation of chemical contaminants, nutrients and ecological indicators such as diatoms throughout the Delaware and Barnegat Bays
2011‐2014+ –Drs. Tracy Quirk and David Velinsky are investigating the factors that maintain marsh elevation (MACWA)
2011‐2016 ‐ Drs. David Velinsky and Tracy Quirk explored ecosystem services of tidal wetlands in tidal freshwater wetlands of DE and marshes in Barnegat Bay 2014 ‐ Present Dr. Beth Watson continues to study marsh function in Delaware and Barnegat Bays (MACWA and Carbon Sequestration)
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Tidal Marshes: Questions
• Ecosystem Services – “Nutrient, contaminants and carbon cycling and storage in marshes along an estuarine salinity gradient” • Climate Change – “Response of marshes to sea‐level rise and salt‐water intrusion” • Land Use Change – “Changing sediments inputs: An unfortunate convergence for tidal marshes”
Ecosystem Productivity
Extreme Desert Desert Scrub Tundra Open Ocean Contiental Shelf Lakes and Streams Grassland Woodland and Shrubland Agricultural Land Savanna Coniferous Forest Temperate Forest Estuaries Tropical Rain Forest Swamps and Marshes
0 200 400 600 800 1000 1200 1400 Average Net Primary Productivity (g C m-2 yr-1)
Total area in US = 1.6 x 1011 m2 (loss is about 0.003 X 1011 m2/yr)
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Marsh Response to Sea Level Rise and Sediment Availability
Wetland accretion and erosion
Accretion
• Local accretion = mass accumulation ÷soil bulk density cm/y g/cm2/y g/cm3 • Absolute accretion = local accretion + subsidence
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SLRDs for 60-yr time series at gauge locations across North America year
per
mm
Delaware Bay 2.8 –4.1 mm yr‐1
Sallenger, A.H. et al. 2012; Nature Climate Change
Consequences of Coastal Shoreline Development and Marsh Removal
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Salt‐Water Intrusion
Changing Precipitation & Evapotranspiration
Tidal Fresh River
Oligohaline
Rising Sea Level
Mesohaline Ocean
Generalized schematic of nitrogen and phosphorus cycling in wetlands
With salt‐water intrusion • Plants and microbial activity are a key component of N and P transformations • In marine sediments, high levels of sulfide from sulfate reduction, bind Fe and allow for greater release of dissolved P
• Result in the potential alteration of the amount of N and P buried relative to loadings (unlike PCBs or some trace metals)
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Causes for concern
1. ALTERED LANDSCAPE ‐ Coastal development ‐ Altered sediment load ‐ Increased nutrient load ‐ Direct human alterations
2. RELATIVE SEA LEVEL RISE ‐ Salinity, tide range increase
Philadelphia Sandy Hook, NJ
2.8 mm/yr 3.9 mm/yr
Lewes, DE Atlantic City, NJ
3.2 mm/yr 4.0 mm/yr
Wetlands provide valuable ecosystem services!
• Water quality improvement (e.g. chemical transformation)
• Floodwater retention and protection
• Biodiversity islands and corridors
• Carbon, nitrogen, phosphorus (i.e., chemical) sequestration
• Locations for human relaxation and nature observation/education
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NJDEP Barnegat Bay Comprehensive Research
Objectives of Projects: 1. Evaluate permanent nitrogen (N) removal services provided by Barnegat Bay coastal wetlands: • Sediment burial of nitrogen, carbon and phosphorus (Yr 0) • Bay‐wide seasonal denitrification rates in salt marshes (Yr 1) • Mosquito control (OMWM) ponds impact on denitrification (Yr 2) • How do OMWMs impact ecosystem services?
2. Combine data to obtain an overall estimate of N removal services provided by Barnegat Bay wetlands.
Q: What are the fates of nitrogen and other nutrients in the Bay?
Wetlands of Barnegat Bay
Areal Extent: 26,900 acres
Saline Wetlands: 21,800 acres
Tidal Freshwater: 5,100 acres
Data from V. Depaul (USGS)
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Barnegat Bay Watershed N load: 4.6 to 8.6 x 105 kg N yr‐1 (from 1998 to 2011; Baker et al. 2014) Symptoms of Eutrophication • phytoplankton and macroalgae blooms • brown tide and HABs • alteration of benthic communities • loss of seagrass and shellfish beds
Barnegat Bay
TN Load = ~ 5 - 9 X105 kg N/yr Sources 34% > Direct Atmospheric Dep. 12% > Groundwater Discharge 54% > Surface Water (Hunchak-Kariouk and Nicholson, 2001)
Load is estimated to be 5X above Rutgers “background” (Kennish et. al. 2007). Univ., CRSSA
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NJ DEP Monitoring Data
Taken from H. Pang (NJ DEP)
Nitrogen and Phosporus NJ DEP Monitoring Data
Total N Dissolved N Ammonia Total P Dissolved P Ortho ‐P
Taken from H. Pang (NJ DEP)
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Wetland Nitrogen Cycle N2 (g) flux
Tidal Exchange Plant uptake Algae and Spartina
‐ + + ‐ Watershed NO3 + NH4 + DON NH flux NO flux 4 3 N&P Loadings WATER SEDIMENT
Organic N + ‐ N OO NHO 4 NOO 3 O2 (g)
Burial Net Ammonification Net Nitrification Denitrification
• More development • Higher Runoff • Higher Nutrient Conc. • Lower Salinities Sampling Program
• Three core locations: upper, mid, and lower reaches. Two cores at each location.
• Sampling in Spring/Summer of 2009-13
• Less development • Lower Runoff • Lower Nutrient Conc. • Higher Salinities
•Taken from Lathrop and Haag (2007)
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Questions How can environmental changes in Barnegat Bay and other areas be monitored over time?
Are management programs succeeding in cleaning up the Bay?
Sediment Cores: An ecosystem’s memory Changes related to: Are reflected by changes in:
land‐use pollen, stable isotopes (SI), metals
aquatic ecology diatoms, shells, SI, CNP, Fe‐S
pollution sources chemicals (phosphorus, lead, DDT)
Importance: climate change, pollution control strategies, response time for change…
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How sediment core data can be used in ? environmental models…..
Forecast Simulate Future Changes Process-based models Simulate Past Hindcast Changes
Core Analysis Model versus Historical Comparisons
Observed Past Paleo-environmental Changes data
Sediments: an ecosystem’s memory
Sediment surface slowly builds up, < Lower Loads burying chemicals/indicators with newer 2010 sediment
Higher Loads >>
1950 1950
Chemical-Sediment Sediment Depth from Sediment Surface
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Sampling Locations
• Reedy Creek (BB-1) • Mid Bay-Wire Pond (BB-2) • Oyster Creek (BB-3) - discharge canal • West Creek (BB-4)
Analytical Parameters
– Organic Carbon, Total Nitrogen and Total Phosphorus – Diatom Species Composition – Stable Isotopes of Carbon (13C) and Nitrogen (15N) – Grain size (< 63 m; clay+silt) – Radioactive Isotopes: 210Pb and 137Cs
Upper Bay 2002 (BB-1)
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Upper Bay 1930 (BB-1)
Middle Bay 2002 (BB-2)
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Middle Bay 1930 (BB-2)
Lower Bay (BB-4)
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Lower Bay 1930 (BB-4)
Push-Piston Core: One of many methods for taking a marsh core
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Sedimentation rates: 210Pb and 137Cs analysis
210 Cs-137 Fallout at New York City 1954-1990 Pb sediment cycling 4 US EPA, EML (NYC) Peak
3 2
2 mCi / km / mCi
1 Onset Half life = 22.5 yrs ~ 150 yrs 0 1950 1960 1970 1980 1990 Year • Particle-reactive
• Pb dating: 100 to 150 yrs • 137Cs: atomic weapons or power plants • Supported 210Pb produced by radioactive • Onset and peak are used to mark age-depth decay within sediments • Assume linear rates between dates • Unsupported 210Pb transported to water from watershed runoff • Particle-reactive; can desorb in marine waters
Profiles of excess 210Pb and 137Cs activity for core BB-1
Core BB1B xsPb-210 (dpm/g) Cs-137 (dpm/g) Calendar year 0.01 0.1 1 10 02468101875 1900 1925 1950 1975 2000 0
5
10 "1964"
15
r2=0.81 20
Depth in core (cm) core in Depth 25
30 CIC model CRS model 35
Note: Pb ages based on the CIC model
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Profiles of excess 210Pb and 137Cs activity for core BB-2
Core BB2A xsPb-210 (dpm/g) Cs-137 (dpm/g) Calendar year 0.01 0.1 1 10 02468101875 1900 1925 1950 1975 2000 0
5 "1964" 10 r2=0.94 15
20
Depth incore (cm) 25
30 CIC model CRS model 35
Note: Pb ages based on the CIC model
Comparison between Delaware and Barnegat Bays: Accretion Rates
Tidal fresh and salt marsh accretion rates in Delaware Estuary: All Sites Mean 0.72 ±0.21 cm/yr, n=29 Barnegat Bay Sites: Max 1.1 cm/yr All Sites Mean 0.25 ±0.06 cm/yr, n= 4 Min 0.39 cm/yr Max 0.29 cm/yr Salt Marshes Mean 0.65 ± 0.17 cm/yr, n=17 Min 0.16 cm/yr Max 1.0 cm/yr Min 0.39 cm/yr Tidal Freshwater Marshes Mean 0.85 ± 0.24 cm/yr, n=12 Max 1.1 cm/yr Min 0.60 cm/yr
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Total Organic Carbon (%) Distribution of CNP with Depth 0 10203040 0 10203040 0 102030400 10203040 0
20 • Robust levels of CNP in BB marsh
40 sediments
60 • Generally higher concentrations in the Depth (cm) Depth 80 upper sections, with more constant levels at BB-1 BB-2 BB-3 BB-4 100 depth TN-Sediments (%) • Very high P level observed at the surface of 0.00.51.01.50.0 0.5 1.0 1.5 0.0 0.5 1.0 1.5 0.0 0.5 1.0 1.5 0 BB-4
20 • The C to N ratio is fairly constant in the 40 upper 40 cm, except for Core BB-2 60
Sediment Depth (cm) Depth Sediment 80 C to N ratio (molar)
100 0 10203040500 10203040500 10203040500 1020304050 0 Sediment Phosphorus (%)
0.00.10.20.30.0 0.1 0.2 0.3 0.0 0.1 0.2 0.3 0.0 0.1 0.2 0.3 0.4 0 20
20 40
40 60 Depth (cm) Depth 60 80
Sediment Depth (cm) Depth Sediment 80 BB-1 BB-2 BB-3 BB-4 100
100
13C-Sediment (%) Stable Isotopes of C and N: -30-25-20-15 -30 -25 -20 -15 -30 -25 -20 -15 -30-25-20-15 0 Indicators of sources and cycling
20
40 • Spartina sp are C4 plants and would yield 13C of OC at ~ -15 to -12 ‰ 60
Sediment Depth (cm) Depth Sediment 80 • Terrestrial plants in this area, as well as BB-1 BB-2 BB-3 BB-4 Mantoloking Mid-Bay Oyster Creek Parkertown 13 100 algae, are C3 plants and would yield C of
15 OC at ~ -30 to - 18 ‰ (algae are more N-Sediment (‰) 13 024 024 024 024 enriched in C) 0
15 20 • The N of TN can reflect biogeochemical
40 processes (e.g., denitrification) as well as changes in sources to the bay. 60
80 Sediment Depth (cm) Depth Sediment BB-1 BB-2 BB-3 BB-4 100 X= [(Rsample/Rstd) – 1] X 1000 (‰) where is X is either 13C or 15N and 13 12 15 14 Rsample = C/ C or N/ N
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1.5 6 BB-1 4 1.0 TN Changes in N with Time 2 0.5 15 N-TN 0 • Increase N concentrations starting 0.0 around the 1940s 1.5 6 BB-2 4 15 1.0 Col 6 vs Col 11 • The N-TN increases from 0-1 per mill Col 6 vs Col 9
2 to ~ 4 per mill at the surface 0.5
0 N (‰)
0.0 15 • Suggest more sewage-derived N was/is 1.5 6 being introduced to the bay (..has it BB-3 4 1.0 changed?)
2 0.5 Sediment 0 0.0 1.5 6
Total Sediment Nitrogen (%) Total Sediment N BB-4 15 N-TN 4 1.0
2 0.5
0 0.0 1800 1850 1900 1950 2000 Year
-10 BB-1 13 C-OC -15 0.2 Changes in P with Time -20 0.1 -25 • Slight increase in P concentrations with TSP 0.0 -30 time -10 0.2 BB-2 13 -15 • The C-OC does not change
-20 substantially with time (past 50 yrs) 0.1 except at BB-3 -25
0.0 -30 -10 • Lack of relationship between P and 0.2 BB-3 13 -15 C-OC suggest that P is not TSP 13 C-OC -20 controlling system wide productivity as 0.1 (‰) OC C-Sediment shown in other aquatic environments -25 13 Total Sediment P (% dw) (% P Sediment Total 0.0 -30 -10 • Large shift at BB-3 reflects changes in 0.4 BB-4 -15 vegetation type over time 0.3 -20 0.2
0.1 -25
0.0 -30 1800 1850 1900 1950 2000 Year
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Changes at BB -3 Potential Changes in: • Vegetation type (C3 versus C4) • C speciation (either source changes or related to temperature increase)
-10
C Marine diatoms
13 -15 -20
(‰) Freshwater diatoms -25
-30 Sediment 1800 1850 1900 1950 2000 Year
1930s 2000s
How much N and P are Buried in the Marshes of Barnegat Bay?
Nitrogen Accumulation Rates (mg N/cm2-yr)
0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Accumulation of N&P over Time
2000
1980 • Using [N or P], sediment mass, and accretion rates to calculate 1960 accumulation rates over time
Time (years) 1940
1920 • Rates change with time, with a general BB-1 BB-2 BB-3 BB-4 1900 increase in most cores starting in the Phosphorus Accumulation Rates (mg P/cm2-yr) ~1950s/1960s
0.00 0.02 0.04 0.06 0.08 0.00 0.02 0.04 0.06 0.08 0.00 0.02 0.04 0.06 0.08 0.00 0.05 0.10 0.15 2000 • No distinct north-south gradient in rates 1980 (highest rate for P at BB-4)
1960
Time (years) 1940 • Can use rates at the surface and over time to estimate sequestration of N and 1920
BB-1 BB-2 BB-3 BB-4 P from wetland sediments 1900 Burial rate = 5.2 ±0.7 g N m‐2 yr‐1 (n = 4)
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Wetland Nitrogen Cycle N2 (g) flux
Tidal Exchange Plant uptake Algae and Spartina
‐ + + ‐ Watershed NO3 + NH4 + DON NH flux NO flux 4 3 N&P Loadings WATER SEDIMENT
Organic N + ‐ N OO NHO 4 NOO 3 O2 (g)
Burial Net Ammonification Net Nitrification Denitrification
Comparison of Barnegat Bay marsh nitrogen and phosphorus burial rates measured in this study to rates of nitrogen and phosphorus inputs to the Barnegat Bay. Nitrogen (kg/yr X105) Phosphorus (kg/yr X105) Inputs 6.9 1.0
Marsh Burial: Core Top Concentration 6.45 0.88 Avg Concentration (50yrs) 5.48 0.54
Burial as % of Inputs Core Top Concentration 94% 88% Avg. Concentration (50yrs) 79±11% 54±34% Nitrogen inputs ranged from 6.5 to 7.65 X105 kg/yr (Hunchak, 2001; Wieben and Baker, 2009; Kennish et al., 2007) while phosphorus input is derived from the Barnegat Bay Characterization Report. Wetland area (26,000 acres, 1.1 X108 m2) are obtained from www.crssa.rutgers.edu/ projects/lc/. Barnegat Bay wetlands can sequester a substantial amount of N and P
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Diatoms as Indicators of Ecological Change
Indicators of Many Different Variables • Nutrient Levels • Salinity-Conductivity •pH • Benthic/Planktonic • Water Level • Water Clarity
Smol, J.P. 2008. Pollution of Lakes and Rivers Sample and Data Needs: • Well preserved samples • Calibration set (diatom species versus stressor) • Adequate separation of the different groups • Robust change in environmental parameter
Diatoms as Indicators of Ecological Change sp. 4
sp. 1 taxa
sp. 3 sp. 5
of sp. 6 sp. 2 Abundance
Low Nutrient >>>>>>>>>>> High Nutrient Various species of diatoms have variable tolerances for environmental parameters
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Core BB1: diatom‐based inference shows strong N enrichment starting from 1940s
Manasquan Inlet
Cranberry Inlet
Core BB4: some N increase starting from 1800s
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Barnegat Bay Marshes: Denitrification
Seasonal denitrification rates . 3 salt marshes in north, mid‐, and south bay . 6 cores per marsh . 3 times per year (May, July, October) . Analyze cores for N‐ fluxes, oxygen demand, sediment carbon and nitrogen . Determine average bay‐wide flux rates (g N m‐2 d‐1)
Wetland Nitrogen Cycle N2 (g) flux
Tidal Exchange Plant uptake Algae and Spartina
‐ + + ‐ Watershed NO3 + NH4 + DON NH flux NO flux 4 3 N&P Loadings WATER SEDIMENT
Organic N + ‐ N OO NHO 4 NOO 3 O2 (g)
Burial Net Ammonification Net Nitrification Denitrification
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Factors that can Limit Denitrification in Sediments
• Dissolved oxygen • Hydrogen sulfide • Lower pH • Amt of labile carbon (i.e., easily degradable OC) • Available nitrate (coupling of nitrification‐denitrification)
• Question: Importance of Anammox1 and DNRA pathways?
1 ammonium was being converted to N2 (gas)
Denitrification Rates in Three Salt Marshes in Barnegat Bay
200 May 180 July October 160 Reedy /hr) 2
140
120
100 IBSP 80
60
Horse production rate (umol/m
2 40 N 20
0 Reedy IBSP Horse Site MONTH N Production (μmol/m2/hr) Other salt marshes 2 May 83 ±14ab 12 – 290 μmol/m2/hr July 121 ±20a (Valiela et al. 2000) October 49 ±19b
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What are Open Marsh Water Management (OMWM) Systems?
Strafford 2002 Strafford 2013
Mosquito control: since the 1970’s the Ocean County Mosquito Extermination Commission has created over 9,000 ponds across 12,000 acres of salt marsh in Barnegat Bay, NJ.
• Limited amount of information about how it affects marsh accretion and ecosystem services
• How much is enough?: balance between human health and ecosystem health
Barnegat Bay’s West Creek in 2002
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Barnegat Bay’s West Creek in 2013
Variation in Vegetated Sediments: Limited Ability to Detect Differences
250 July 17, 2012 Horse Creek (southern bay) /hr)
2 200
150
100
50 production rate (umol/m production 2 N
0 Veg Control Veg OMWM Pond OMWM Treatment
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Comparison of N2 Production Among Study Sites
250
) Edwin B. Forsythe National May -1 Jul Wildlife Refuge: 2014 hr 200 Oct -2
150
100
50 production (umol m 2 N 0
ds M k n W ree M hes Po c C O it hes c D it Non-OMWMD Site characteristics
Summary of Denitrification Study
Open water (OMWM) vs Vegetated marsh • Denitrification variable in vegetated marsh • Much less variable in open water interior marsh sites • No substantial difference between marsh open water and vegetated sites
• No relationship between porewater sulfide and N2 production
Open Marsh Water Management (OMWM)
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Wetland Nitrogen Cycle N2 (g) flux
Tidal Exchange Plant uptake Algae and Spartina
‐ + + ‐ Watershed NO3 + NH4 + DON NH flux NO flux 4 3 N&P Loadings WATER SEDIMENT
Organic N + ‐ N OO NHO 4 NOO 3 O2 (g)
Burial Net Ammonification Net Nitrification Denitrification
Comparison of Barnegat Bay Marsh Nitrogen Removal Rates Measured to Rates of Nitrogen Inputs to Barnegat Bay Nitrogen (kg/yr X105) Inputs (1989-2011; Median) 6.73 Marsh Burial: Core Top Concentrations 6.1 ± 0.02 Avg Concentrations (50yrs) 5.2 ± 0.71
Burial as % of Inputs Core Top Concentrations 91% Avg. Concentrations (50yrs) 77%
Marsh Denitrification: May 0.47 July 0.70 Oct 0.30 Avg ± SD 0.49 ± 0.20 Denitrification as % of Inputs 7.30% Total Removal 84-98% Nitrogen inputs ranged from 4.6 to 8.6 X105 kg/yr (1989‐2011; Baker et al., 2014) Wetland area (26,900 acres, 1.1 X108 m2) are obtained from www.crssa.rutgers.edu/ projects/lc/ and V. Depaul (USGS)
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Summary and Conclusions
• Remaining wetlands play important role in nutrient cycles in Bay • Plant uptake‐sediment burial can sequester carbon, nitrogen and phosphorus (nutrient trading?) • Denitrification is an important process for nitrogen removal in wetlands • OMWM sites have similar rates in whole marsh • Studies showcase the importance of BB wetlands and maintaining and increasing area
Acknowledgements Patrick Center for Environmental Research Roger Thomas Paul Kiry Mike Archer Melissa Bross Stephen Dench Megan Nyquist Kirk Raper Linda Zaoudeh Paula Zelanko
We thank the support of Thomas Belton and NJ DEP.
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Barnegat Bay’s West Creek in 2013
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