Quality of dissolved organic C (DOC) from main-stem and tributary sites along the Ogeechee River was compared to that of chemically defined organic C substrates in terms of biological availability. Availability was determined by measuring bacterial growth on natural river water (collected at high and low discharges) and defined organic substrates (humic standards and high-quality sources of C). Availability of DOC to the natural (native) stream bacterial assemblage was compared to that of a defined bacterial inoculum, selected for ability to readily utilize high-quality substrates. Availability of DOC declined downriver, and DOC in highly colored tributaries was of lower quality than DOC from other sites. In most cases, quality of DOC decreased at high discharge.
Limnology and Oceanography
Leff, Laura Gunn; Meyer, Judy L. (1991). Biological Availability of Dissolved Organic Carbon along the Ogeechee River. Limnology and Oceanography 36(2) 315-323. Retrieved from https://oaks.kent.edu/bscipubs/70