Abstract
Accurate delineation of hypoxic zones is crucial for effective management decisions and conservation efforts, directly impacting the blue economy, particularly fisheries and tourism along the Gulf Coast of the United States. By identifying these vulnerable areas, conservation initiatives can help protect the economic vitality of coastal communities reliant on industries like commercial fisheries and tourism. Hypoxia in the Gulf of Mexico poses a multifaced environmental issue marked by seasonal fluctuations, spatial variability, and considerable impacts on marine ecosystems. This study utilizes field and remote sensing data to develop machine learning models that classify hypoxic patches in the northern and eastern Gulf of Mexico. Random Forest and XGBoost were identified as the most effective models, achieving the highest accuracy, precision, recall, and F1 scores. These models were employed to generate seasonal predictions of hypoxic zones over a continuous decade (2011–2020), facilitating an examination of interannual and spatial variation in hypoxia dynamics. Results demonstrate pronounced differences in hypoxic area extent across seasons and regions, with the highest occurrences noted during summer. The mean predicted hypoxic area in summer is approximately 69,363 km², with a high probability of occurrence under typical seasonal and environmental conditions. Hypoxic regions are primarily located on the continental shelf of the northern Gulf, particularly near river mouths, with peak intensity recorded near the Mississippi River (mean ≈ 0.58) and Atchafalaya River (mean ≈ 0.41). Additionally, smaller rivers such as the Apalachicola, Pearl, and Suwannee Rivers exhibit high densities of hypoxic zones near their confluences. Seasonal hypoxia is also observed on the West Florida shelf, often linked to red tide events. By mapping hypoxic hotspots and analyzing their seasonal variability, this study provides vital insights that facilitate informed decision-making and sustainable marine resource management, emphasizing the link between ecological and economic health in the Gulf Coast region.
