Response p of Salt-Marshes and Tidal Freshwater Marshes in the Delaware River Estuary to Sea-Level Sea Level Rise and Salt-Water Intrusion Nathaniel B. Weston Department of Geography and the Environment, Villanova University Delaware Estuary Science and Environmental Summit February 2011
Coastal Marshes and Sea Level Extensive Coastal Marshes Formed in last ~4000 years
Sea level rise was too rapid (~10 mm yr-1) for marsh formation
Intergovernmental Panel on Climate Change Fourth Assessment Report (2007)
How will tidal marshes in the Delaware River Estuary respond to current and future rates of sea-level rise?
Sea-Level Rise & Marsh Accretion Watershed I Inputs t
CO2 Primary
Production
Marsh Accretion Inorganic Sediment
Organic O i Matter
MSL
Tidal Freshwater M Marshes h PA
De
law
e Riv are
r
NJ
Raccoon MD
Salt Marshes Delaware Bay DE
Atlantic Ocean
Salt-Water Intrusion Changing Precipitation & Evapotranspiration i i
River Rising Sea Level
Ocean
TFM Plant Response to Salt-water Salt water Intrusion Freshwater tidal marsh plant (Nuphar luteum) luteum)…
…dies when transplanted to a brackish marsh.
Salt-marsh cordgrass (Spartina alterniflora) grows the following year. year
Shift to Salt Marsh? Watershed I Inputs t
CO2 Primary
Production
Marsh Accretion Inorganic Sediment
Organic O i Matter
MSL
Adjacent d Marsh h Mesocosms Average Maximum Daily Flooding (cm)
TFM Mesocosms
Sediment Traps
50 60 70 80 90 100 • Plant Pl S Species i C Composition i i & Bi Biomass • Trace GHG (CH4 & N2O) Flux • Soil Biogeochemistry & Microbial Rates • Rates R off Sediment S di D Deposition ii
Delaware River Transplant Experiment
Delaware Estuary Salinity y y 16
3000
14
River Discharge
Stow (salt‐marsh) Stow (salt marsh)
2 00 2500
2000 10 8
1500
Salem (brackish)
6 1000
Organs 4
500
Rancocas (TFM) Raccoon (TFM)
2 0
0 Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
River Disscharge (m3 s-1)
Conductivity (mS cm m-1)
12
Plant Species Response to Flooding Depth 90 Zizania aquatica (brackish)
80 70
Mixed TFM
Bio omass (g)
60
Spartina alterniflora (salt)
50 40 30
Peltandra virginica (fresh)
20 10
Nuphar lutea (fresh)
0 40
50
60
70
80
90
Average Daily Maximum Flooding Depth (cm)
100
110
120
Total Plant Biomass Response to Flooding Depth 90
Rancocas (TFM) 80
Salem (Brackish)
70
Bio omass (g)
60 50
Stow (Brackish‐Salt)
40
Raccoon (Lower TFM)
30 20 10 0 40
50
60
70
80
g y g p ( ) Average Daily Maximum Flooding Depth (cm)
90
100
110
Total Plant Biomass Response to Flooding Depth 90
Rancocas (TFM) 80 70
Bio omass (g)
60 50
Raccoon Transplant
40
Raccoon (Lower TFM)
30 20 10 0 40
50
60
70
80
g y g p ( ) Average Daily Maximum Flooding Depth (cm)
90
100
110
14 1.4
3000 Rancocas Raccoon
1.2
2500
Delaware River Discharge
2000 0.8 1500 0.6 1000 04 0.4
500
0.2
0
0 Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
River Disccharge (m 3 s-1)
Conductivity (mS cm -11)
1
Total Plant Biomass Response to Flooding Depth 90
Rancocas (TFM) 80
Salem (Brackish)
70
Bio omass (g)
60 50 40 30 20
Salem Transplant
10 0 40
50
60
70
80
g y g p ( ) Average Daily Maximum Flooding Depth (cm)
90
100
110
Total Plant Biomass Response to Flooding Depth 90
Rancocas (TFM) 80 70
Bio omass (g)
60 50
Stow (Brackish‐Salt)
40 30 20 10
S Stow T Transplant l 0 40
50
60
70
80
g y g p ( ) Average Daily Maximum Flooding Depth (cm)
90
100
110
Unstable Marsh / Open Water
Stable Marsh
Relative e Plant B Biomass and M Marsh Acc cretion
Marsh Accretion
Sea Level Rise
Marsh Platform
Plant Biomass
Salt-tolerant Plant Colonization
Marsh Accretion
20
30
40
50
60
70
80
Average Daily Maximum Flooding Depth (cm)
90
100
*Patrick Costello *Amanda Foskett Oliva Gibb Anthony Geneva Paul Kiry C Chris McLaughlin Avni Malhotra *Neil Mehta *Justin Meschter Stephen Mowbray
*Michael Patson *Melanie Pingoy *Tatjana j Prša James Quinn *Daniel Russo *Mariozza Mariozza Santini Kimberli Scott Roger Thomas *John John Ufferfilge Melanie Vile *Paul Weibel (* - Undergraduate Student)
Environmental Protection Agency, STAR Program National Science Foundation Villanova University
80
CO2
70
Salt‐water Amended
Salt-water Amended
CO2 Flux ((mmol m-2 d-1)
60
50
40
30
Freshwater
20
Freshwater
10
0 -30
0
30
60
90
120
150
180
210
240
270
300
330
360
390
Time (days y) 200
CH4
180
CH4 Fluux (mmol m-2 d-1)
160 140 120 100 80 60 40 20 0 -20 -30
0
30
60
90
120
150
180
210
Time (days)
240
270
300
330
360
390
Soil Organic Carbon -2
Organiic Carbo on (mol m )
660
Freshwater Salt Water Intrusion
640 620 600 580 560 540 520 -50
0
50
100
150
200
Days
250
300
350
400
Impact of Coupled Sea‐Level Rise and Salt‐water Intrusion 140 120