Dissolved Organic Matter Composition in Doboy Sound and the Altamaha River near Sapelo Island, Georgia in 2012-2013

The composition of dissolved organic matter (DOM) in the Altamaha River estuary and Doboy Sound near Sapelo Island, Georgia, was investigated at the molecular level using ultrahigh-resolution mass spectrometry and stable carbon isotope analyses. DOM samples were collected in November 2012, May 2013, and September 2013 representing different hydrological regimes, including anomalously low-discharge conditions. DOM was also collected from water as it flooded and ebbed from an extensive marsh area at Sapelo Island in May 2013. The untargeted approach used allowed for identifying the DOM molecular signatures associated with different DOM sources in the estuary.