Photochemical production of dissolved organic carbon from resuspended sediments

• DOI: 10.4319/lo.2006.51.5.2187
• Publication Date: 2010-07-01T18:00:35Z
• Authors: Robert J. Kieber; Robert F. Whitehead; Stephen A. Skrabal
• Keywords: Photosynthetically active radiation

A series of controlled photolysis experiments using simulated sunlight was conducted in the presence and absence estuarine bottom sediments to address role sediment resuspension on dissolved organic carbon (DOC) cycling coastal waters. In 0.2-µm-filtered water samples with no added sediment, DOC concentrations decreased from 0.4 3 µmol L-1 h-1 as a result photooxidation. When addition 1-2 grams per liter were irradiated, produced at rates 150 gram dry sediment. Photoproduction resuspended increased direct proportion percent content Highenergy ultraviolet light most effective for photodegrading filtered photoproducing sediments. Photosynthetically active radiation (PAR; 400-700 nm) did not significantly degrade water. However, PAR produce half much organic-rich regions estuary relative full spectrum irradiations. The photoproduction sediments, calculated top 1 m waters, resulted fluxes that larger than benthic riverine DOC. therefore represents an episodically significant but previously unrecognized source ecosystems receiving large plumes.