Projects

Evaluating success of beneficial use restoration on Deer Island

End Date: 01/31/2020

How do habitat stewards and scientists determine the return on investment (ROI) of coastal salt marsh restoration projects? One research team at the University of Southern Mississippi is looking to quantify restoration success in terms of ecosystem services. Patrick Biber, Zachary Darnell and Kevin Dillon are measuring carbon and nitrogen values in natural and restored marsh sites on Deer Island, Mississippi, as a proof-of-concept pilot project. The research team is quantifying how carbon and nitrogen move through the food chain in the marsh – from the marsh environment to small invertebrates to larger organisms. In addition, they are quantifying the capacity of carbon storage in salt marsh sediments over time. They will determine the change in these two ecosystem services over time by assessing recent (since 2016) and established (since 2005) restored marshes and comparing them to a natural reference marsh. The information on ecosystem services valuation will be applicable to large-scale restoration activities across the Gulf of Mexico region.

 

Abstract

Coastal salt marshes in the Gulf of Mexico are highly productive habitats. Mississippi has lost about 10,000 acres of coastal wetland habitat dominated by black needlerush since 1950. The Gulf is experiencing a dramatic increase in restoration actions to offset the loss of coastal habitats. With millions of dollars being invested, it is critical to have consistent and comprehensive assessment and monitoring protocols to help determine the return on investment of restoration projects using an ecosystem services (ES) perspective. We propose to determine select ES related to important carbon and nitrogen cycling in sediments and vegetation and (1) their trophic transfer to macroinvertebrates that are forage for higher trophic levels, (2) the role of sequestered carbon in the sediments over time. The proposed study will focus on Deer Island, MS, as a proof-of-concept pilot project site. The objectives of this proposal are to:

  1. Use quantitative data to evaluate sediments, vegetation and microalgae, and macroinvertebrates in (1) natural reference marsh site, (2) recently restored site (since 2016), and (3) established restored site (since 2005),
  2. Undertake analysis on these collected samples for tissue elemental (C, N) and stable isotope (del13C, del15N) analysis to elucidate (1) trophic transfer and (2) blue C capacity of restoration over time, and
  3. Calculate the anticipated ROI at decadal time points of these two important ES as the restoration matures over the expected 30 year engineering life span.

Interested user groups of this information include USACE, MDMR Beneficial Use Group, MS Habitat Stewards, and Restore America’s Estuaries Blue Carbon Gulf Regional Initiative, and all require more research information to better serve their constituents and endeavors. The information on restoration success and ES valuation developed by this research will be applicable to many of the largescale restoration activities anticipated in this region over the coming decades. 

Objectives

The proposed study will focus on Deer Island, MS, as a proof-of-concept pilot project site. 

The objectives of this proposal are to: 

  • Use quantitative data to evaluate sediments, vegetation and microalgae, and macroinvertebrates in (1) natural reference marsh site, (2) recently restored site (since 2016), and (3) established restored site (since 2005),
  • Undertake analysis on these collected samples for tissue elemental (C, N) and stable isotope (del13C, del15N) analysis to elucidate (1) trophic transfer and (2) blue C capacity of restoration over time, and
  • Calculate the anticipated ROI at decadal time points of these two important ES as the restoration matures over the expected 30 year engineering life span.

Methodology

The goal of this Sea Grant proposal is to better understand the ES benefits related to C and N that restoration of coastal marsh habitats provide in terms of both trophic transfer and blue C capacity using restorations at Deer Island. Field sampling for vegetation biomass, soil composition, and macroinvertebrate density takes place twice a year (spring and fall) at the three sampling sites identified using quantitative methods for plant, and macroinvertebrate community components. New elements we propose to add include: sediment composition (grain size and OM content), benthic microalgae, and elemental and stable isotope analysis of all the collected samples.

For Task 1, there are three subtasks that will be completed for sediment and primary producers, including Benthic Microalgae (BMA) and vascular plant vegetation sampling, under the direction of Dr. Biber. Task 2, invertebrate sampling, under the direction of Dr. Darnell, will focus on motile macroinvertebrates. Task 3 will be processing and analyses of sediment, vegetation, and macroinvertebrate tissue samples collected to determine elemental (C, N) contents and stable isotope ratios (del13C, del15N) under the direction of Dr. Dillon. It is estimated that almost 650 samples, comprised of 192 samples for vegetation, 96 for BMA, 48 sediments, and 120 fiddler crab, 120 periwinkle, and 72 blue crab for a total of 312 animal tissue samples will be analyzed. Finally, Task 4 will be to develop a database of ES valuation for ecosystem goods and services provided by coastal marsh habitats. Another focus of this task will be to apply the only Verified Carbon Standards (VCS VM0033) approved blue carbon accounting methodology for coastal wetlands. Quantification of lost ecosystem services resulting from immature coastal marsh function during the early successional phase of the BU project is needed to more fully calculate the overall ROI of the project.

Rationale

Coastal salt marshes in the Gulf of Mexico are highly productive habitats. Mississippi has lost about 10,000 acres of coastal wetland habitat dominated by black needlerush since 1950. The Gulf is experiencing a dramatic increase in restoration actions to offset the loss of coastal habitats. With millions of dollars being invested, it is critical to have consistent and comprehensive assessment and monitoring protocols to help determine the return on investment of restoration projects using an ecosystem services (ES) perspective. We propose to determine select ES related to important carbon and nitrogen cycling in sediments and vegetation and (1) their trophic transfer to macroinvertebrates that are forage for higher trophic levels, (2) the role of sequestered carbon in the sediments over time. The hypothesis to be tested is: Ecosystem services, in the form of sediment nutrient pools and blue C, are not fully available from restoration activities until the site matures past a late successional vegetation-dominated phase (10+ years). The proposed research will address the MASGC 2018-2020 Research Funding priorities in: (1) Focus Area of Healthy Coastal Ecosystems – “calculate the return on investment for ecosystem services provided by coastal restoration projects that have been implemented in Mississippi and Alabama”; and “test methods to evaluate on-the-ground coastal habitat restoration projects in Mississippi and Alabama to improve techniques that measure restoration success”. Identified user groups of this information include USACE, MS Dept Marine Resources (MDMR) Beneficial Use Group, MS Habitat Stewards Muck-to-Marshes (M2M) program, and Restore America’s Estuaries (RAE) Blue Carbon Gulf Regional Initiative. The information on restoration success and ES valuation developed by this research will be applicable to many of the large-scale restoration activities anticipated in this region over the coming decades.