Department or Program

Earth and Climate Sciences

Abstract

Deliberate burial of discard kelp biomass has been proposed as a marine carbon dioxide removal strategy. Compound specific isotopic analysis of amino acids has the potential to trace organic matter sources into sediments. A three-month microcosm experiment with a flow through system consisting of S. latissima on top of sediment from the Damariscotta River was conducted to determine whether S. latissima is buried in sediments. S. latissima and sediments were analyzed for molar concentrations and stable carbon isotope composition of individual amino acids. The concentration of individual amino acids is higher in both the microcosm sediment and kelp compared to the given starting materials, suggesting addition of bacterial- derived organic matter throughout the experiment. δ13C values of individual amino acids are more depleted in the microcosm sediment relative to the starting sediment and there is variation in the microcosm kelp relative to the starting kelp representative of bacterial alteration. δ13C values for phenylalanine and valine of S. latissima and microcosm sediment did not fall within values for bacteria and macroalgae cited in the literature, indicating that there is likely another endmember in the kelp and sediment that is not represented. Although there is an input of organic matter in the microcosm sediment, the origin of this material may be a combination of S. latissima and bacteria. Future work requires determining the percentage of S. latissima and bacteria in the sediment with endmembers specific to the microcosm experiment to create a Bayesian mixing model using δ13C values of individual amino acids.

Level of Access

Restricted: Embargoed [Open Access After Expiration]

First Advisor

Johnson, Beverly

Date of Graduation

5-2026

Degree Name

Bachelor of Arts

Number of Pages

75

Components of Thesis

1 pdf file

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Embargoed

Available to all on Saturday, May 08, 2027

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