Environmental gradients shape the hydrocarbon-degrading microbiome in two mid-Atlantic bays.

Environmental gradients, including salinity and seasonality, significantly influence the abundance and activity of hydrocarbon-degrading microbes in two mid-Atlantic estuaries.

• Why it matters: Understanding how abiotic and biotic factors shape hydrocarbon degradation is crucial for predicting ecosystem responses to pollution and environmental change in coastal estuaries, which are heavily contaminated.
• What they did: The study analyzed metagenomes, metatranscriptomes, and MAGs from surface waters of Delaware and Chesapeake Bays, focusing on genes involved in hydrocarbon degradation and their expression across different environmental conditions.
• The result: Hydrocarbon degradation pathways, especially aromatic and alkane, are more abundant in low-salinity spring and summer samples, with taxa like Pseudomonadales and Burkholderiales employing diverse strategies that support ecosystem resilience.