SUMMARY: Antibiotics that have made their way into aquatic ecosystems may have an effect on the food chains there. This study tested the effects of ciprofloxacin hydrochloride on 2 different types of algae (phytoplankton) and a species of rotifer (zooplankton). The populations of these organisms were measured by their density. Antibiotics had a direct effect on the individual organisms, decreasing population density for all three. Organisms were then put into the same tank (a community tank), to observe their relationship with each other and how that differed with the addition of ciprofloxacin. For the control community tank, the population plateaued out for all three species after 10 days. For the community tank with ciprofloxacin hydrochloride added, rotifer density dropped with increasing levels of the antibiotic. One algae species increased but then decreased. The other algae species increased with the increasing levels of antibiotics. The discussion section talks about the significance of this inverse relationship between microorganisms and antibiotics.
LESSON COMMENTS: A great article to talk about ecosystem relationships and pollution. While one can test toxins and pollutants on one specific organism, it is important to remember that these organisms do not exist in their natural habitat alone. There is a constant ebb and flow of zooplankton and phytoplankton that have an effect on the entire food chain. It is important to understand and be able to predict how toxins and pollutants can affect our aquatic ecosystems.
C. Wang, Z. Wang, Y. Zhang, and R. Su, “Interspecies Interactions Reverse the Hazard of Antibiotics Exposure: A Plankton Community Study on Responses to Ciprofloxacin hydrochloride,” Scientific Reports, vol. 7, no. 1, 2017.