Lingering Carbon Cycle Effects of Hurricane Matthew in North Carolina's Coastal Waters

In 2016, Hurricane Matthew accounted for 25% of the annual riverine C loading to the Neuse River Estuary-Pamlico Sound, in eastern North Carolina. Unlike inland watersheds, dissolved organic carbon (DOC) was the dominant component of C flux from this coastal watershed and stable carbon isotope and chromophoric dissolved organic matter evidence indicated the estuary and sound were dominated by wetland-derived terrigenous organic matter sources for several months following the storm. Persistence of wetland-derived DOC enabled its degradation to carbon dioxide (CO2), which was supported by sea-to-air CO2 fluxes measured in the sound weeks after the storm. Under future increasingly extreme weather events such as Hurricane Matthew, and most recently Hurricane Florence (September 2018), degradation of terrestrial DOC in floodwaters could increase flux of CO2 from estuaries and coastal waters to the atmosphere