Macro- and microelements in Cladophora (Chlorophyta) biomass and bottom sediments of a marine hypersaline lake (Crimea)

Abstract

The contents of 27 elements were analyzed in the green macroalga Cladophora biomass and bottom sediments of a marine hypersaline lake (Black Sea). Concentrations of Li, Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ag, Tl, Pb, B, Na, Mg, Al, K, Ca, Sr, Ba were measured using inductively coupled plasma mass spectrometry. Ca, K, Mg, and Na showed the highest average concentrations in Cladophora at 76,69 mg kg⁻¹, 55,58 mg kg⁻¹, 15,46 mg kg⁻¹, and 9,02 mg kg⁻¹, respectively. Relatively high concentrations were recorded for Sr (1,73 mg kg⁻¹), B (1,14 mg kg⁻¹), and Al (459 mg kg⁻¹). Other elements had much lower average concentrations: from 35.84 mg kg⁻¹ for Zn to 0.05 mg kg⁻¹ for Tl. Concentrations of most chemical elements in bottom sediments exceeded those in Cladophora biomass, with Al, Li, Pb, and Ti concentrations over 10 times higher than in the algae; the average concentrations of B, Se, Sr, and Mn in algal biomass were 3.5, 3.6, 1.9, and 1.8 times those in bottom sediments, respectively. A strong positive correlation was found between element levels in the lake's bottom sediments and in Cladophora biomass. The chemical element content varies vertically within the Cladophora mat due to the spatial characteristics of its biological, physical, and chemical structure.