Aureococcus anophagefferens growth potential affected by coastal water toxicants

Abstract

Brown tide blooms, caused by excessive growth of the pelagophyte Aureococcus anophagefferens Hargraves et Sieburth (Ochrophyta, Pelagophyceae), have been observed to be spreading in new water bodies with substantial human influences. This study quantified A. anophagefferens growth potential as affected by common pollutants—heavy metals, herbicide metolachlor, and secondary-treated sewage effluent. Culture studies show that A. anophagefferens growth potential was not affected by environmentally relevant levels of metolachlor but was reduced at low salinity or addition of 10–15 % sewage effluent. When exposed to Cd, Cu, and Zn at high but environmentally relevant concentrations, A. anophagefferens growth potential was reduced, but Zn antagonized inhibitive effect from Cu and CdCu. Preliminary field incubation showed that adding Ni, Cu, Zn, or EDTA did not significantly alter A. anophagefferens survival in filtered Newark Bay seawaters (NJ, USA), suggesting tolerance of A. anophagefferens to anthropogenic toxicants. These results may aid on the understanding and modeling of A. anophagefferens expansion in polluted estuaries.