Impact of Mercury (II) Nitrate on Physiological and Biochemical Characteristics of Selected Marine Algae of Different Classes

Short-term physiological and biochemical responses induced by mercury(II) nitrate (Hg(NO3)2) in three marine macroalgae, Gracilaria salicornia (Rhodophyceae), Sargassum sp. (Phaeophyceae) and Ulva reticulata (Chlorophyceae) were studied. All algae were good accumulators of Hg. However, this characteristic significantly decreases in G. salicornia and significantly increases in U. reticulata as concentration of Hg increases. Algal FV/FM, chlorophyll (chl) a content and relative growth showed a significant reduction in the presence of Hg. Hg impact was prominent in FV/FM than the other parameters while a small impact was shown by the relative growth. Hg induced synthesis of new amino acids and inhibit the production of some. The profile even changed when the concentration of Hg(NO3)2 increases.