Quantum yield spectra for the photochemical formation of biologically labile photoproducts from dissolved organic matter (DOM) have not been available previously, although they would greatly facilitate attempts to model photoproduct formation rates across latitudinal, seasonal, and depth‐related changes in spectral irradiance. Apparent quantum yield spectra were calculated for two coastal environments from the southeastern Uni...

Terrestrially derived dissolved organic matter (DOM) impacts the optical properties of coastal seawater and affects carbon cycling on a global scale. We studied sequential long‐term photochemical and biological degradation of estuarine dissolved organic matter from the Satilla River, an estuary in the southeastern United States that is dominated by vascular plant‐derived organic matter. During photodegradation, dissolved organ...