Coastal drainages contain multiple sources of dissolved organic matter (DOM) that influence OM transformation and fate along inland‐to‐marine gradients. Anthropogenic activities have altered DOM composition in urban drainages, thereby influencing in‐stream breakdown rates, primary productivity, and downstream export. Yet, it is uncertain how hydrologic conditions (i.e., rainfall, tides, shallow groundwater) interact with different sources of DOM to regulate the transformation and export of DOM through urban coastal drainages. We characterized how seasonal changes in hydrologic conditions influence DOM composition and bioavailability in tidally influenced drainages in Miami, FL, USA. We estimated the quality and bioavailability of DOM using compositional proxies based on fluorescence spectroscopy, including parallel‐factor analysis, and measured dissolved organic carbon degradation during laboratory incubations containing a local bacterial community. Interactions between stormwater runoff and tidal amplitude increased the bioavailability of DOM and were positively correlated with predominantly humic‐like components in the wet season and protein‐like components in the dry season. Further, increases in tryptophan fluorescence intensity corresponded with elevated concentrations of
- NSF-PAR ID:
- 10312738
- Date Published:
- Journal Name:
- Frontiers in Marine Science
- Volume:
- 8
- ISSN:
- 2296-7745
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/fmars.2021.781580
