The effect of pH on the growth of Licmophora abbreviata

  • Mona Akbarnejad
  • Arvin Bahrabadi
  • Louise Meddings
  • Brandon Wei


Licmophora abbreviata is a species of diatom that is crucial in the salmon food chain as primary producers, and in its contribution to atmospheric oxygen. It is sensitive to a wide range of abiotic factors; pH was tested in this study. Our experiment was conducted over a two-week period, starting by diluting a stock solution of L. abbreviata to a concentration of 1.0 x 10^4 cells/ mL in 3 treatments of different pH’s: 7, 8 and 9, with three replicates of each. Every second day, a sample from each culture was fixed and counted to determine its concentration. Counts were done for 6 days over an 11-day period. Using daily observed counts, growth rates were calculated and a one-way ANOVA test was performed, yielding a p-value = 0.875, which found that the mean growth rates between treatments were not significantly different. The results may have been influenced by the changing pH of the media, resulting from diatoms’ metabolic activities in vitro, as well as the relatively short time period over which the study was done. In conclusion, there was no association found between pH and the average growth rate of Licmophora abbreviata.