There are long-standing concerns about the environmental impacts of large dams such as Iron Gate I, the Danube River's largest hydropower scheme, which stretches for 135 kilometers along the river, covers an area of 104 square kilometers, and contains up to 2.1 cubic kilometers of water [Friedl and Wuest, 2002]. During the onset of Black Sea coastal eutrophication resulting from increased nitrogen (N) and phosphorus (P) loads, the dissolved silica (DSi) concentration at the Danube discharge was reported to have decreased by approximately two thirds [Cociasu et al., 1996]. Coinciding with the completion of Iron Gate I in 1972, researchers pointed to DSi removal in the reservoir to explain the shift in algal dominance in the Black Sea from diatoms to nuisance blue-green algae, which apparently resulted in reduced fish-catches.