2017 Delaware Estuary Science and Environmental Summit Cape May, NJ January

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1 2017 Delaware Estuary Science and Environmental Summit Cape May, NJ January Beatrice O Hara Dr. Daria Nikitina, Advisor West Chester University of Pennsylvania Department of Earth and Space Sciences

2 Acknowledgements WCU Blue Carbon Team Advisor Dr. Daria Nikitina Field & 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 Funding Support NASA Pennsylvania State Grant Consortium New Jersey DEP Grant SR New Jersey Sea Grant WCU College of Science and Math Graduate Assistantship

3 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

4 Get in the Zone LEGEND: Salt Marsh Depositional Env. High Marsh HM Mixed Marsh MM Low Marsh LM Open Water CL

5 Carbon in.carbon out CO 2 Carbon sequestration via photosynthesis Carbon emissions via plant respiration or oxidation due to land use changes or erosion Most of the sequestered carbon is stored in the sediments/soils. >95% of total carbon stocks are found in the below ground sediments/soils

6 Good things take time DE Bay salt marshes have been developing under sea level rise for 8,000 years Salt marshes adapt to sea level rise by accreting vertically and migrating landward Relative Sea Level (m) Age (years) Nikitina et al. 2015; Horton et al Simon Mudd, Jeremy Lowe,

7 History always tells a story 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 Infilling elevation Δ depositional environment elevation Δ depositional environment Modified from Nikitina et al. 2014

8 Let me take you there Reed et al. 2008; Titus et al. 2008

9 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 cm 3 every 5 cm DBD, LOI, %Organic Carbon (C org ) using Craft et al equation, Sediment Carbon Density (SCD) AMS 14 C, 137 Cs and 206 Pb: 207 Pb concentrations courtesy of Daria Nikitina and Nikitina et al. 2014

10 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 (C org) ranges from 0.6 % to 44.6% High Marsh Fibrous Peat Mixed Marsh Peat & organic mud Low Marsh Organic mud Tidal Flat/ Open Water Mud Paleosol Humic sandy mud Sand

11 Depositional Environment Differences %C org 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 %C org difference is significant between all depositional environments except between the Mixed Marsh and the Low Marsh 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

12 Carbon 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 Murray et al No studies account for carbon stock through the entire sediment sequence

13 Carbon Accumulate Rate Comparisons Short term CAR (~ top 1 meter) is 1.92 MgC/h/yr Long term CAR (~ 1 3 meters) is MgC/h/yr Short term CAR shows regional variation Our results are comparable with recent studies in the Delaware Bay 1 Choi and Wang 2004, 2 Churma et al 2003, 3 Ouyong and Lee 2014, 4 Elsey Quirk et al. 2011, 5 Tucker 2015 unpublished

14 Summary 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.