Water column turbidity, chlorophyll-a content, and dissolved inorganic macronutrients were measured in Ross Barnett Reservoir, a turbid, artificial water body located in central Mississippi. Measurements indicated that abundant nutrients were present, whereas levels of chlorophyll-a were substantially below expectation. Significant inorganic turbidity and the resulting low transparency suggested rapid extinction of light within the water column. Sediment settling in an experimental microcosm led to rapid increase in chlorophyll-a, consistent with the notion that algal biomass abundance was limited by light, rather than nutrients. Based on our results, an antagonistic relationship between the inorganic turbidity and inorganic nutrients exists in the reservoir, the former modulating effects of the latter and thus limiting the potential for algal blooms. Should suspended sediment be removed without addressing nutrients at the same time, algal biomass is expected to increase dramatically. Likewise, high levels of dissolved inorganic nutrients, together with limited competition from the planktonic algae create an ideal set of conditions for floating macrophyte mats to develop.