The effect of nickel on the growth of the freshwater diatom Navicula pelliculosa

Abstract

The effect of nickel on the growth of the freshwater diatom Navicula pelliculosa was determined by noting differences in the growth rate and number of cells present in laboratory cultures exposed to 0, 100, 300 and 600 μg/litre nickel for 14 days. Nickel concentrations as low as 100 μg/litre (1·7 × 10⁻⁶M) reduced the population growth rate by 50% and led to decreased 14-day cell numbers. Calculation of the equilibrium composition of the culture medium showed that 99·8% of the total nickel added existed as Ni⁺². The occurrence of Ni⁺² in the medium was associated with reduced algal growth.