Dr. David Velinsky€¦ · Causes for concern 1. ALTERED LANDSCAPE ‐Coastal development...
Transcript of Dr. David Velinsky€¦ · Causes for concern 1. ALTERED LANDSCAPE ‐Coastal development...
12/14/2016
1
Tidal Marshes of Barnegat Bay: Nutrient History and Ecosystem Services
Dr. David Velinsky
Patrick Center for Environmental ResearchThe Academy of Natural Sciences of Drexel University &
Department Head, Biodiversity Earth and Environmental Science
December 2016
Tracy Quirk2, Chris Sommerfield3, Jeff Cornwell4, Ashley Smyth5
and Mike Owens42Department of Oceanography and Coastal Sciences, Louisiana State University3School of Marine Science & Policy, University of Delaware4Center for Environmental Science, University of Maryland‐Horn Point5presently at Kansas Biological Survey, University of Kansas
Collaborators:
Drs. Marina Potopova and Elizabeth Watson both at Academy of
Natural Sciences and Drexel University; Dept. of Biodiversity, Earth and Environmental Science
12/14/2016
2
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)
12/14/2016
3
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
0 200 400 600 800 1000 1200 1400
Swamps and Marshes
Tropical Rain Forest
Estuaries
Temperate Forest
Coniferous Forest
Savanna
Agricultural Land
Woodland and Shrubland
Grassland
Lakes and Streams
Contiental Shelf
Open Ocean
Tundra
Desert Scrub
Extreme Desert
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)
12/14/2016
4
Marsh Response to Sea Level Rise and Sediment Availability
Wetland accretion and erosion
• Local accretion = mass accumulation ÷ soil bulk densitycm/y g/cm2/y g/cm3
• Absolute accretion = local accretion + subsidence
Accretion
12/14/2016
5
Delaware Bay2.8 – 4.1 mm yr‐1
mm per year
SLRDs for 60-yr time series at gauge locations across North America
Sallenger, A.H. et al. 2012; Nature Climate Change
Consequences of Coastal Shoreline Development and Marsh Removal
12/14/2016
6
Salt‐Water Intrusion
River
Ocean
ChangingPrecipitation &
Evapotranspiration
RisingSea Level
Tidal Fresh
Oligohaline
Mesohaline
Generalized schematic of nitrogen and phosphorus
cycling in wetlands
• 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)
With salt‐water intrusion
12/14/2016
7
Philadelphia
2.8 mm/yr
Sandy Hook, NJ
3.9 mm/yr
4.0 mm/yr3.2 mm/yr
Atlantic City, NJLewes, DE
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
• 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
Wetlands provide valuable ecosystem services!
12/14/2016
8
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.
Objectives of Projects:
NJDEP Barnegat Bay Comprehensive Research
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)
12/14/2016
9
Barnegat Bay
Symptoms of Eutrophication• phytoplankton and macroalgae blooms• brown tide and HABs• alteration of benthic communities• loss of seagrass and shellfish beds
Watershed N load: 4.6 to 8.6 x 105 kg N yr‐1(from 1998 to 2011; Baker et al. 2014)
TN Load = ~ 5 - 9 X105 kg N/yr
Sources34% > Direct Atmospheric Dep.12% > Groundwater Discharge54% > Surface Water
(Hunchak-Kariouk and Nicholson, 2001)
Load is estimated to be 5X above“background” (Kennish et. al. 2007).Rutgers
Univ., CRSSA
Barnegat Bay
12/14/2016
10
NJ DEP Monitoring Data
Taken from H. Pang (NJ DEP)
Nitrogen and Phosporus NJ DEP Monitoring Data
Taken from H. Pang (NJ DEP)
Total NDissolved N
AmmoniaTotal PDissolved P
Ortho ‐P
12/14/2016
11
OO
SEDIMENT
WATER
Organic N ONH4+
Net Ammonification
N2 (g) flux
ON2 (g)
Denitrification
NO3‐ flux
ONO3‐
Net Nitrification
NH4+ flux
Wetland Nitrogen Cycle
Plant uptakeAlgae and Spartina
NO3‐+ NH4
++ DON
Tidal Exchange
Burial
Watershed N&P Loadings
•Taken from Lathrop and Haag (2007)
• Three core locations: upper, mid, and lower reaches. Two cores at each location.
• Sampling in Spring/Summer of 2009-13
• More development• Higher Runoff• Higher Nutrient Conc.• Lower Salinities
• Less development• Lower Runoff • Lower Nutrient Conc.• Higher Salinities
Sampling Program
12/14/2016
12
How can environmental changes in Barnegat Bay and other areas be monitored over time?
Are management programs succeeding in cleaning up the Bay?
Questions
Sediment Cores: An ecosystem’s memory
land‐use pollen, stable isotopes (SI), metals
aquatic ecology diatoms, shells, SI, CNP, Fe‐S
pollution sources chemicals (phosphorus, lead, DDT)
Changes related to: Are reflected by changes in:
Importance: climate change, pollution control strategies, response time for change…
12/14/2016
13
Paleo-environmentaldata
Model versus HistoricalComparisons
Observed PastChanges
Core Analysis
Process-basedmodels
Forecast
Hindcast
Simulate FutureChanges
Simulate PastChanges
?How sediment core data can be used in environmental models…..
Sediments: an ecosystem’s memory
1950
Dep
th f
rom
Sed
imen
t S
urf
ace
Chemical-SedimentSediment
Sediment surface slowly builds up,burying chemicals/indicators with newer
sediment2010
1950
Higher Loads >>
< Lower Loads
12/14/2016
14
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)
12/14/2016
15
Upper Bay 1930 (BB-1)
Middle Bay 2002 (BB-2)
12/14/2016
16
Middle Bay 1930 (BB-2)
Lower Bay (BB-4)
12/14/2016
17
Lower Bay 1930 (BB-4)
Push-Piston Core: One of many methods for taking a marsh core
12/14/2016
18
Sedimentation rates: 210Pb and 137Cs analysis
210Pb sediment cycling
• 137Cs: atomic weapons or power plants
• Onset and peak are used to mark age-depth
• Assume linear rates between dates
• Particle-reactive; can desorb in marine waters
Half life = 22.5 yrs~ 150 yrs
Cs-137 Fallout at New York City 1954-1990
Year
1950 1960 1970 1980 1990
mC
i / k
m2
0
1
2
3
4
Onset
PeakUS EPA, EML (NYC)
• Particle-reactive
• Pb dating: 100 to 150 yrs
• Supported 210Pb produced by radioactive decay within sediments
• Unsupported 210Pb transported to water from watershed runoff
xsPb-210 (dpm/g)
0.01 0.1 1 10
Dep
th in
cor
e (c
m)
0
5
10
15
20
25
30
35
Core BB1BCs-137 (dpm/g)
0 2 4 6 8 10
r2=0.81
"1964"
Calendar year
1875 1900 1925 1950 1975 2000
CIC modelCRS model
Profiles of excess 210Pb and 137Cs activity for core BB-1
Note: Pb ages based on the CIC model
12/14/2016
19
Core BB2ACs-137 (dpm/g)
0 2 4 6 8 10
"1964"
Calendar year
1875 1900 1925 1950 1975 2000
CIC modelCRS model
xsPb-210 (dpm/g)
0.01 0.1 1 10
Dep
th in
cor
e (c
m)
0
5
10
15
20
25
30
35
r2=0.94
Profiles of excess 210Pb and 137Cs activity for core BB-2
Note: Pb ages based on the CIC model
Tidal fresh and salt marsh accretion rates in Delaware Estuary:
All SitesMean 0.72 ± 0.21 cm/yr, n=29
Max 1.1 cm/yr
Min 0.39 cm/yr
Salt MarshesMean 0.65 ± 0.17 cm/yr, n=17
Max 1.0 cm/yr
Min 0.39 cm/yr
Tidal Freshwater MarshesMean 0.85 ± 0.24 cm/yr, n=12
Max 1.1 cm/yr
Min 0.60 cm/yr
Barnegat Bay Sites:
All SitesMean 0.25 ± 0.06 cm/yr, n= 4
Max 0.29 cm/yr
Min 0.16 cm/yr
Comparison between Delaware and Barnegat Bays: Accretion Rates
12/14/2016
20
Total Organic Carbon (%)
0 10 20 30 40
Dep
th (
cm)
0
20
40
60
80
100
0 10 20 30 40 0 10 20 30 40 0 10 20 30 40
TN-Sediments (%)
0.0 0.5 1.0 1.5
Sed
imen
t D
epth
(cm
)
0
20
40
60
80
100
0.0 0.5 1.0 1.5 0.0 0.5 1.0 1.5 0.0 0.5 1.0 1.5
Sediment Phosphorus (%)
0.0 0.1 0.2 0.30.0 0.1 0.2 0.3
Sed
imen
t D
epth
(cm
)
0
20
40
60
80
100
0.0 0.1 0.2 0.3 0.0 0.1 0.2 0.3 0.4
Distribution of CNP with Depth
• Robust levels of CNP in BB marsh sediments
• Generally higher concentrations in the upper sections, with more constant levels at depth
• Very high P level observed at the surface of BB-4
• The C to N ratio is fairly constant in the upper 40 cm, except for Core BB-2
BB-1 BB-2 BB-3 BB-4
C to N ratio (molar)
0 10 20 30 40 50
Dep
th (
cm)
0
20
40
60
80
100
0 10 20 30 40 50 0 10 20 30 40 50 0 10 20 30 40 50
BB-1 BB-2 BB-3 BB-4
0 2 40 2 40 2 40 2 4
Se
dim
en
t D
epth
(cm
)
0
20
40
60
80
100
15N-Sediment (‰)
-30 -25 -20 -15
13C-Sediment (%)
-30 -25 -20 -15
Se
dim
ent
De
pth
(cm
)
0
20
40
60
80
100
BB-1 Mantoloking
-30 -25 -20 -15 -30 -25 -20 -15
BB-2 Mid-Bay
BB-3 Oyster Creek
BB-4 Parkertown
Stable Isotopes of C and N:Indicators of sources and cycling
• Spartina sp are C4 plants and would yield 13C of OC at ~ -15 to -12 ‰
• Terrestrial plants in this area, as well as algae, are C3 plants and would yield 13C of OC at ~ -30 to - 18 ‰ (algae are more enriched in 13C)
• The 15N of TN can reflect biogeochemical processes (e.g., denitrification) as well as changes in sources to the bay.
X = [(Rsample/Rstd) – 1] X 1000 (‰)
where is X is either 13C or 15N andRsample = 13C/12C or 15N/14N
BB-1 BB-2 BB-3 BB-4
12/14/2016
21
0.0
0.5
1.0
1.5
Se
dim
en
t 1
5N
(‰
)
0
2
4
6
Col 6 vs Col 11 Col 6 vs Col 9
0.0
0.5
1.0
1.5
0
2
4
6
BB-2
BB-1
Year
1800 1850 1900 1950 2000
To
tal S
edim
en
t N
itro
ge
n (
%)
0.0
0.5
1.0
1.5
0
2
4
6
Total Sediment N
15N-TN
0.0
0.5
1.0
1.5
0
2
4
6
BB-3
BB-4
Changes in N with Time
• Increase N concentrations starting around the 1940s
• The 15N-TN increases from 0-1 per mill to ~ 4 per mill at the surface
• Suggest more sewage-derived N was/is being introduced to the bay (..has it changed?)
TN
15N-TN
0.0
0.1
0.2
-30
-25
-20
-15
-10
To
tal
Se
dim
en
t P
(%
dw
)
0.0
0.1
0.2
13
C-S
ed
ime
nt
OC
(‰
)
-30
-25
-20
-15
-10
Year
1800 1850 1900 1950 20000.0
0.1
0.2
0.3
0.4
-30
-25
-20
-15
-10
TSP
13C-OC
0.0
0.1
0.2
-30
-25
-20
-15
-10
Changes in P with Time
• Slight increase in P concentrations with time
• The 13C-OC does not change substantially with time (past 50 yrs) except at BB-3
• Lack of relationship between P and 13C-OC suggest that P is not controlling system wide productivity as shown in other aquatic environments
• Large shift at BB-3 reflects changes in vegetation type over time
BB-1
BB-2
BB-3
BB-4
TSP
13C-OC
12/14/2016
22
Changes at BB -3
1800 1850 1900 1950 2000Sed
imen
t 1
3C
(‰
)
-30
-25
-20
-15
-10
1930s2000s
Year
Potential Changes in:• Vegetation type (C3 versus C4)• C speciation (either source changes or related to temperature increase)
Freshwater diatoms
Marine diatoms
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 1.00.0 0.2 0.4 0.6 0.8 1.0
Tim
e (y
ears
)
1900
1920
1940
1960
1980
2000
BB-1 BB-2 BB-3 BB-4
Phosphorus Accumulation Rates (mg P/cm2-yr)
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 0.150.00 0.02 0.04 0.06 0.08
Tim
e (y
ear
s)
1900
1920
1940
1960
1980
2000
BB-1 BB-2 BB-3 BB-4
Accumulation of N&P over Time
• Using [N or P], sediment mass, and accretion rates to calculate accumulation rates over time
• Rates change with time, with a general increase in most cores starting in the ~1950s/1960s
• No distinct north-south gradient in rates (highest rate for P at BB-4)
• Can use rates at the surface and over time to estimate sequestration of N and P from wetland sediments
How much N and P are Buried in the Marshes of Barnegat Bay?
Burial rate = 5.2 ± 0.7 g N m‐2 yr‐1 (n = 4)
12/14/2016
23
OO
SEDIMENT
WATER
Organic N ONH4+
Net Ammonification
N2 (g) flux
ON2 (g)
Denitrification
NO3‐ flux
ONO3‐
Net Nitrification
NH4+ flux
Wetland Nitrogen Cycle
Plant uptakeAlgae and Spartina
NO3‐+ NH4
++ DON
Tidal Exchange
Burial
Watershed N&P Loadings
Barnegat Bay wetlands can sequester a substantial amount of N and P
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/.
12/14/2016
24
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
Abundance of taxa
Low Nutrient >>>>>>>>>>> High Nutrient
sp. 1
sp. 2
sp. 3
sp. 4
sp. 5sp. 6
Diatoms as Indicators of Ecological Change
Various species of diatoms have variable tolerances for environmental parameters
12/14/2016
25
Core BB1: diatom‐based inference shows strong N enrichment starting from 1940s
Cranberry Inlet
Manasquan Inlet
Core BB4: some N increase starting from 1800s
12/14/2016
26
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)
OO
SEDIMENT
WATER
Organic N ONH4+
Net Ammonification
N2 (g) flux
ON2 (g)
Denitrification
NO3‐ flux
ONO3‐
Net Nitrification
NH4+ flux
Wetland Nitrogen Cycle
Plant uptakeAlgae and Spartina
NO3‐+ NH4
++ DON
Tidal Exchange
Burial
Watershed N&P Loadings
12/14/2016
27
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
IBSP
Reedy
Horse
MONTH N2 Production (μmol/m2/hr)May 83 ± 14ab
July 121 ± 20a
October 49 ± 19b
Site
Reedy IBSP Horse
N2 p
rod
uct
ion
rat
e (u
mo
l/m
2 /hr)
0
20
40
60
80
100
120
140
160
180
200MayJulyOctober
Other salt marshes12 – 290 μmol/m2/hr(Valiela et al. 2000)
12/14/2016
28
What are Open Marsh Water Management (OMWM) Systems?
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
Strafford 2002 Strafford 2013
Barnegat Bay’sWest Creek in
2002
12/14/2016
29
Barnegat Bay’sWest Creek in
2013
Variation in Vegetated Sediments: Limited Ability to Detect Differences
July 17, 2012
Treatment
Veg Control Veg OMWM Pond OMWM
N2
pro
du
ctio
n r
ate
(um
ol/m
2/h
r)
0
50
100
150
200
250
Horse Creek (southern bay)
12/14/2016
30
Site characteristics
N2
pro
du
ctio
n (
um
ol m
-2 h
r-1)
0
50
100
150
200
250
MayJulOct
Ponds
OMW
M
Ditches
Non-OM
WM
Ditches Cre
ek
Comparison of N2 Production Among Study Sites
Edwin B. Forsythe National Wildlife Refuge: 2014
Summary of Denitrification Study
• 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 water (OMWM) vs Vegetated marsh
Open Marsh Water Management (OMWM)
12/14/2016
31
OO
SEDIMENT
WATER
Organic N ONH4+
Net Ammonification
N2 (g) flux
ON2 (g)
Denitrification
NO3‐ flux
ONO3‐
Net Nitrification
NH4+ flux
Wetland Nitrogen Cycle
Plant uptakeAlgae and Spartina
NO3‐+ NH4
++ DON
Tidal Exchange
Burial
Watershed N&P Loadings
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)
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 InputsCore Top Concentrations 91%
Avg. Concentrations (50yrs) 77%
Marsh Denitrification:May 0.47July 0.70Oct 0.30
Avg ± SD 0.49 ± 0.20
Denitrification as % of Inputs 7.30%
Total Removal 84-98%
12/14/2016
32
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
AcknowledgementsPatrick Center for Environmental ResearchRoger ThomasPaul KiryMike ArcherMelissa BrossStephen Dench Megan NyquistKirk RaperLinda ZaoudehPaula Zelanko
We thank the support of Thomas Belton and NJ DEP.
12/14/2016
33
Barnegat Bay’sWest Creek in
2013