OS13A-2022
Nitrogen deposition fuels harmful algal blooms in the East China Sea
Monday, 14 December 2015
Poster Hall (Moscone South)
Katherine R Mackey1, Maria Kavanaugh2, Chia-Te Chien3, Ying Chen4, David M Glover5 and Adina Paytan3, (1)University of California Irvine, Earth System Science, Irvine, CA, United States, (2)Woods Hole Oceanographic Institution, Woods Hole, United States, (3)UCSC-Inst Marine Sciences, Santa Cruz, CA, United States, (4)Fudan University, Shanghai, China, (5)Woods Hole Oceanographic Institution, Woods Hole, MA, United States
Abstract:
Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication and increasing harmful algal blooms (HABs). Here we provide direct experimental evidence that aerosol enrichment shifts seawater chemistry by increasing the ratio of N to phosphorus (N:P) and supports the growth of bloom-forming phytoplankton in the East China Sea. We use a combination of field-based aerosol addition incubation experiments, along with ocean color data on blooms dominated by different taxa to show that HAB forming dinoflagellates are particularly responsive to aerosol inputs. Moreover, we show that the effect of N deposition is strongest in offshore waters further from the Yangtze River outflow, consistent with the large anthropogenic flux of N from this source. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community, contributing to the success of bloom-forming organisms.
