2017 delaware estuary science and environmental summit · •the results show that the delaware bay...
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2017 Delaware Estuary Science and Environmental SummitCape May, NJ January 22‐25 2017
Beatrice O’HaraDr. Daria Nikitina, AdvisorWest Chester University of PennsylvaniaDepartment of Earth and Space Sciences
Funding SupportNASA Pennsylvania State Grant Consortium
New Jersey DEP Grant SR15‐007
New Jersey Sea Grant 6410‐0012
WCU College of Science and Math Graduate Assistantship
Funding SupportNASA Pennsylvania State Grant Consortium
New Jersey DEP Grant SR15‐007
New Jersey Sea Grant 6410‐0012
WCU College of Science and Math Graduate Assistantship
AcknowledgementsAcknowledgements
WCU Blue Carbon TeamAdvisor – Dr. Daria NikitinaField & lab work – Dan Jennings, Deven Scelfo, Matt Serzega, Steve Esrey, Al Geyer, Jason Zallie, Alex Roccaro, Melanie Flynn, Lily Fanok, and Vivi the shih tzu
WCU Blue Carbon TeamAdvisor – Dr. Daria NikitinaField & lab work – Dan Jennings, Deven Scelfo, Matt Serzega, Steve Esrey, Al Geyer, Jason Zallie, Alex Roccaro, Melanie Flynn, Lily Fanok, and Vivi the shih tzu
There’s no place like home…There’s no place like home…
• Protection from storm surge and sea level rise
• Prevention of shoreline erosion • Recycling of nutrients • Filtration of water pollution • Breeding and feeding grounds for aquatic
animals• Livelihood and recreation for humans• Exchange of GHG between soil and
atmosphere
Get in the Zone…Get in the Zone…
HighMarshHM
Low Marsh LM
Mixed MarshMM
Open WaterCL
LEGEND: Salt Marsh Depositional Env.
Carbon in….Carbon outCarbon in….Carbon outCO2CO2
Carbon sequestration via photosynthesis
Most of the sequestered carbon is stored in the sediments/soils.
Carbon emissions via plant respiration or oxidation due to land use changes or erosion
>95% of total carbon stocks are found in the below ground sediments/soils
Good things take time…Good things take time…DE Bay salt marshes have been developing under sea‐level rise for 8,000 years
Age (years)
Relative Se
a Le
vel (m)
Nikitina et al. 2015; Horton et al. 2013 Jeremy Lowe, http://serc.carleton.edu/vignettes/collection/42858.html
Simon Mudd, http://www.ed.ac.uk/geosciences/
Salt marshes adapt to sea‐level rise by accreting vertically and migrating landward
History always tells a story…History always tells a story…
Modified from Nikitina et al. 2014
The marsh stratigraphic record provides a window to the past where storm erosion, tidal creek migration, channeling/ditching, changes to sediment supply, and sea level rise are all possibilities.
Erosion elevation Δ depositional environment
Infilling elevation Δ depositional environment
Reed et al. 2008; Titus et al. 2008
Let me take you there…Let me take you there…
This is how we do it…This is how we do it…
• 19 sediment cores were sampled
• All cores taken through the entire depth of the marsh
sediments
• Established depositional environments
• Sample size = 9.8 cm3 every 5 cm
• DBD, LOI, %Organic Carbon (Corg) using Craft et al. 1995
equation, Sediment Carbon Density (SCD)
• AMS 14C, 137Cs and 206Pb:207Pb concentrations courtesy
of Daria Nikitina and Nikitina et al. 2014
Results are in….Results are in….
• Average depth of sediments:• Fortescue = 2.40 m• Sea Breeze = 2.75 m
• 6 lithologic units:• 4 salt marsh depositional
environments• 2 pre‐salt marsh
environments
• % Organic Carbon (Corg) ranges from 0.6 % to 44.6%
FibrousPeat
Peat & organic mud
HighMarsh
Low Marsh
Mixed Marsh
Tidal Flat/Open Water
Organicmud Mud
Humic sandy mud
Paleosol Sand
• 60% of the stored carbon is derived from High Marsh sediments
• 33% of the stored carbon is derived from High Marsh sediments at depths >1m
Depositional Environment DifferencesDepositional Environment Differences• %Corg in the depositional environments varies with sediment type ranging from 4.6 % in the tidal flat sediments to 17.3 % in the high‐marsh sediments
• %Corg difference is significant between all depositional environments except between the Mixed Marsh and the Low Marsh
Carbon Stock ComparisonsCarbon Stock Comparisons
• Mean Sediment Carbon Stock (SCS) is comparable at both study sites
• SCS increases with depth from a mean of 369 MgC/h in top 1 m to 1,020 MgC/h in top 2.6 m
• Total carbon storage is 66,093 MgC
• Mean SCS to 1 m depth are comparable to other NE regional studies
• No studies account for carbon stock through the entire sediment sequence
Murray et al. 2011
Carbon Accumulate Rate ComparisonsCarbon Accumulate Rate Comparisons
• Short‐term CAR (~ top 1 meter) is 1.92 MgC/h/yr• Long‐term CAR (~ 1‐3 meters) is 0.728 MgC/h/yr• Short‐term CAR shows regional variation• Our results are comparable with recent studies in the Delaware Bay
1Choi and Wang 2004, 2Churma et al 2003, 3Ouyong and Lee 2014, 4Elsey‐Quirk et al. 2011, 5Tucker 2015 unpublished
SummarySummary• Traditionally, carbon stocks are assessed to a depth of 1 meter. • We have calculated carbon stock through the entire sediment sequence.• Estimates of carbon stock ranged from 369 MgC/h at 1 meter depth to 1,147 MgC/h at 3 meters depth.
• We have documented variation in sediment type and % organic carbon within the entire sediment sequence.
• % Corg varies with the depositional environment.• The results show that the Delaware Bay salt marshes sequester significant amounts of carbon and suggest that carbon stock assessments that focus only on the top 1 meter of sediment sequence underestimate the total carbon stock by more than three‐fold.
• When salt marshes erode due to SLR and storms or are degraded through land use changes, carbon emissions could be greater than predicted if the carbon stored at depth has not been taken into account.