Organic Matter Content and Grain Size Analysis in Seagrass Sediments

Presenter and Co-Authors

Adriana Amrhein, Old Dominion UniversityFollow
Rip Hale, Old Dominion UniversityFollow

College

College of Sciences

Department

Ocean & Earth Sciences

Graduate Level

Master’s

Publication Date

2023

DOI

10.25883/ptzc-8955

Abstract

Anthropogenic stresses including increased water temperatures, decreased water quality, sea level rise, ocean acidification and sediment biogeochemical processes have caused a significant loss in seagrass meadow acreage. Seagrass meadows provide coastal protection from storms and recently have been emphasized for their importance in sequestering and storing “Blue Carbon” from the atmosphere and ocean. Seagrass meadows can trap this blue carbon in their sediment as organic carbon, and it can be stored for hundreds to thousands of years. Restoration efforts of seagrass meadows in the Virginia coast started in the 1990s and effects of increasing seagrass density can be observed in sediment cores. Three sediment cores were obtained from South Bay within the Virginia Coast in June of 2022. These cores were tested for particle size and organic matter percentage. Finer sediments were found in the top 20 cm of sediment cores with an increase in particle size with depth. Organic matter percentage was highest in shallow sediments and decreased with depth. These observed relationships show that the increase in seagrass density has led to an increase in carbon sequestration in South Bay sediments. Variations in particle size and organic matter percentage with depth may be due to spatial and seasonal differences observed in seagrass meadows.

Keywords

Blue Carbon, Seagrasses, Ecosystem Services

Disciplines

Geochemistry | Sedimentology | Soil Science

Files

Recommended Citation

Amrhein, Adriana and Hale, Rip, "Organic Matter Content and Grain Size Analysis in Seagrass Sediments" (2023). College of Sciences Posters. 15.
https://digitalcommons.odu.edu/gradposters2023_sciences/15