The effect of Myriophyllum aquaticum on freshwater bodies in British Columbia

  • Rosalyn Desa
  • Shirvin Lee


Myriophyllum aquaticum is an invasive plant species originating from the Amazon River and is currently found in British Columbia. We hypothesized that freshwater sources with Myriophyllum aquaticum would have lower dissolved oxygen content compared to areas without Myriophyllum aquaticum. During this experiment, 40 water samples were collected from each of our four sites: Serpentine Fen (Surrey, B.C.), Nicomekl River (Surrey, B.C.), Alpine Garden Pond and Meyer Glade at the University of British Columbia Botanical Garden (Vancouver, B.C.). Serpentine Fen had Myriophyllum aquaticum while the other three sites were control sites. The dissolved oxygen content (mg/L) was measured with an oxygen meter and recorded for comparison. When comparing the data from Serpentine Fen to Nicomekl River, Alpine Garden Pond and Meyer Glade, a paired t-test was used. P-values of 2.2753E-22, 1.082E-29 and 9.0394E-29 were obtained for these sites. Since they are all less than 0.05, the null hypothesis was rejected and support was provided for the alternate hypothesis that Myriophyllum aquaticum decreases the dissolved oxygen content in freshwater bodies. The results also suggest that a decrease in temperature may increase the dissolved oxygen content because numerous biota cannot survive the colder temperatures, thus less oxygen is being used.