ORCID

0009-0001-7543-7480

Keywords

biogeochemistry, basalt fiber, restoration, oyster reefs, nutrients, coastal ecosystems

Abstract

Concern over the effects of microplastics on estuarine ecosystems and public health has prompted many restoration practitioners to switch from plastic materials to more “natural” substrates. These natural (BESE-biopolymer, cement-jute structures) and non-plastic (basalt fiber) materials should not contain harmful substances; however, their chemical composition is unknown. Natural materials may degrade faster in subtropical environments and release nutrients into surrounding waters, which is concerning for eutrophic restoration areas. Basalt fiber bags, made from melted basalt rock spun into fibers, have not been evaluated for biogeochemical impacts within estuaries. To address this knowledge gap, two field experiments and two laboratory experiments were complemented by a chemical evaluation of these three non-plastic restoration materials to gain a comprehensive understanding of their potential impacts on soil and water biogeochemistry. In the field, material effects on sediment biogeochemical properties at 6 months post-restoration and mass loss of materials deployed in litterbags at sites in Texas and Florida were quantified. Material chemical composition and nutrient release under field and laboratory conditions were also quantified. For basalt fiber only, impacts on microbial respiration rate, biomass, and enzyme activity was also assessed. Field studies showed no impact of materials on sediment properties over the short-term (6-months), but BESE-mesh and basalt fiber lost, respectively, 11.82 ± 0.42 and 1.96 ± 0.24 % of their mass during the same time period. Laboratory nutrient leaching studies showed cement-jute released the most nitrogen (5.00 ± 0.27 mg kg-1) and greater release of organic carbon by basalt fiber 2049.603 ± 42.716 mg kg-1) than other materials. Microbial study results suggest basalt fiber could stimulate microbial activity and release of nutrients from sediment. These results support that these alternative materials are not inert and demonstrate the need to consider all possible effects on ecosystem health and water quality before choosing a restoration material.

Completion Date

2026

Semester

Spring

Committee Chair

Lisa G. Chambers

Degree

Master of Science (M.S.)

College

College of Sciences

Department

Biological Sciences

Document Type

Dissertation/Thesis

Identifier

DP0053273

Download

Share

COinS
 

Accessibility Statement

This item was created or digitized prior to April 24, 2027, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.