NANOMATERIALS ENHANCE ALGAL RESPONSE TO EUTROPHICATION IN A LONG-TERM FIELD MESOCOSM EXPERIMENT
With increased adoption of engineered nanomaterials in agricultural, biomedical and commercial industries comes an increased impetus to understand their effects on downstream ecosystems. To examine the impacts of nanomaterials on wetland ecosystems, we conducted a nine-month mesocosm experiment receiving weekly low-concentration additions of Au and Cu(OH)2 ENM under oligotrophic and eutrophic conditions. Given the potential susceptibility of phytoplankton to nanomaterial toxicity, we examined in-situ chlorophyll-a concentrations weekly and characterized phytoplankton every 3 months. Chlorophyll-a concentration in eutrophic treatments increased relative to controls by 6-18 fold in Au and 4-9 fold in Cu treatments in spring and late summer. Significant negative and positive effects were found in the oligotrophic conditions, but the magnitude was more variable in comparison to eutrophic conditions. Additionally, cumulative number of algal bloom days in both nanomaterial treatments increased 0.15-0.31 fold in oligotrophic and 2.7-3.3 fold in eutrophic treatments relative to the controls. Our results show that chronic exposures to Au and Cu nanomaterials increased the occurrence of algal blooms in wetland mesocosms, especially in eutrophic conditions. These findings raise questions on the long-term potential consequences on water quality and ecosystem health.
Steve Anderson (Primary Presenter/Author), Duke University, firstname.lastname@example.org;
Marie Simonin ( Co-Presenter/Co-Author), Duke University, email@example.com;
Christina Bergemann ( Co-Presenter/Co-Author), Duke University, firstname.lastname@example.org;
Ben Colman ( Co-Presenter/Co-Author), University of Montana, email@example.com;
Emily Bernhardt ( Co-Presenter/Co-Author), Duke University, firstname.lastname@example.org;