Abstract
In the northern Gulf of Mexico, shelf hypoxia poses serious risks to fisheries, coastal economies, and ecosystem health. Although a primary driver of dissolved oxygen dynamics is nutrient loading, physical forcing (wind conditions, stratification, etc.) and their interannual variability also have a role in the coastal shelf regions. This project aims to assess hypoxia and related physical stressors on the Alabama shelf, where little monitoring has occurred despite growing evidence of substantial hypoxic conditions. The connections between extreme events (tropical storms, marine heatwaves), physical stressors (temperature, stratification, wind), and hypoxia occurrence were investigated using a unique long-term mooring dataset of bottom dissolved oxygen measured at ~30 min intervals from 2023 to 2025. The results of this study are expected to facilitate the development of more effective mitigation and adaptation strategies to address the impacts of physical processes on hypoxia in coastal oceans.
Purpose
High-frequency, long-term measurements of dissolved oxygen were made to better understand the frequency, duration, and intensity of hypoxia in coastal Alabama. Dissolved oxygen measurements were made with a Sea Bird Electronics Microcat CTD SMP with an Optical Dissolved Oxygen sensor (ODO). The instruments sampling frequency was typically every 30 minutes, with deployment durations typically between 6-12 weeks. The mooring site is ~16 km south of Dauphin Island on the 20 m isobath.
DOI: 10.57778/gsez-z844
Suggested Citation
Dzwonkowski, B., Puzhankara, A., Lehrter, J., Mohan Rao, D. R., & Lockridge, G. (2026). Bottom hydrographic data from the Fisheries Oceanography in Coastal Alabama (FOCAL) mooring from 2023-06-01 to 2025-12-31 [Dataset]. Dauphin Island Sea Lab. https://doi.org/10.57778/GSEZ-Z844
Related Publication Citation
Attribution
This project was paid for [in part] with federal funding for the Alabama Center of Excellence from the Department of the Treasury under the Resources and Ecosystems Sustainability, Tourist Opportunities, and Revived Economies of the Gulf Coast States Act of 2012 (RESTORE Act) in cooperation with the State of Alabama Department of Conservation and Natural Resources under the Alabama Center of Excellence Program at the MESC/Dauphin Island Sea Lab.
