183-3 A Preliminary Analysis of Diatom Assemblages in Sediments from the Sabine-Neches Estuary, Texas, USA

Session: Recent Advances and New Voices in Marine and Coastal Geoscience (Posters)

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Abstract:

The Sabine-Neches Estuary (SNE) in Southeast Texas, an area known for chemical manufacturing and oil refineries, has undergone extensive anthropogenic alteration since the late 1800s. Impacts of industrialization, dredging, and heavy ship traffic, including sediment resuspension and heavy metal contamination within the estuary, have been documented in previous studies of the area. However, there is a notable gap in data regarding the ecological response to historic disturbances in the SNE, particularly within microfaunal communities. Diatoms, a group of single-celled, siliceous algae, are highly sensitive to a wide range of physical and chemical parameters including temperature, salinity, pH, nutrients, turbidity, and pollutants. Their rapid response to ecological shifts and excellent preservation in sediments make them a useful tool for assessing current and historical water quality in both freshwater and marine environments. In estuarine systems, where environmental gradients vary and anthropogenic stressors are often present, diatom assemblages can reflect subtle changes in ecosystem health that may or may not be captured in chemical analysis alone. Despite widespread use of diatoms in freshwater and marine ecological studies, diatoms have been largely unstudied in the SNE. This study presents a preliminary analysis of diatom assemblages preserved in sediment cores collected from three locations within the SNE. Three sediment cores were collected from the northern, southern, and central portions of the SNE and sampled at three-centimeter intervals for diatom slide preparation. An initial examination of the diatom assemblages in the SNE yielded taxa belonging to the genera Actinocyclus, Diploneis, Gomphoneis, Lindavia, Staurosirella, Thalassiosira, and Tryblionella. Paired with forthcoming geochemical and geochronological data, findings from this study will aid in recognizing the impacts of industrialization on the microfaunal community in the SNE.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10737

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