Impact of air emissions from shipping on marine phytoplankton growth

Research output: Contribution to journalArticlepeer-review

Authors

  • Chao Zhang
  • Junri Zhao
  • Yan Zhang
  • Yang Yu
  • Yingchun Mu
  • Xiaohong Yao
  • Limin Feng
  • Fan Zhang
  • Yingjun Chen
  • Xiaohuan Liu
  • Jinhui Shi
  • Huiwang Gao

Colleges, School and Institutes

External organisations

  • Ocean University of China
  • Qingdao National Laboratory for Marine Science and Technology
  • Fudan University
  • Chinese Research Academy of Environmental Sciences
  • Chinese Academy of Sciences
  • Key Laboratory of Brain Functional Genomics, Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics, East China Normal University, Shanghai

Abstract

With the rapid expansion of maritime traffic, increases in air emissions from shipping have exacerbated numerous environmental issues, including air pollution and climate change. However, the effects of such emissions on marine biogeochemistry remain poorly understood. Here, we collected ship-emitted particles (SEPs) from the stack of a heavy-oil-powered vessel using an onboard emission test system and investigated the impact of SEPs on phytoplankton growth over the northwest Pacific Ocean (NWPO). In SEP microcosm experiments conducted in oceanic zones with different trophic statuses, the phytoplankton response, as indicated by chlorophyll a (Chl a), has been shown to increase with the proportion of SEP-derived nitrogen (N) relative to N stocks (PSN) in baseline seawater, suggesting that SEPs generally promote phytoplankton growth via N fertilisation. Simulations using an air quality model combined with a ship emission inventory further showed that oxidised N (NOx) emissions from shipping contributed ~43% of the atmospheric N deposition flux in the NWPO. Air emissions from shipping (e.g. NOx and sulphur dioxide) also indirectly enhanced the deposition of reduced N that existed in the atmosphere, constituting ~15% of the atmospheric N deposition flux. These results suggest that the impact of airborne ship emissions on atmospheric N deposition is comparable to that of land-based emissions in the NWPO. Based on the ship-induced PSN in surface seawater calculated by modeling results and World Ocean Atlas 2013 nutrient dataset, and the well-established quantitative relationship between Chl a and PSN obtained from microcosm experiments, we found a noticeable change in surface Chl a concentrations due to N deposition derived from marine traffic in the NWPO, particularly in the coastal waters of the Yellow Sea and open oceans. This work attempts to establish a direct link between marine productivity and air emissions from shipping.

Bibliographic note

Funding Information: This work was funded by National Natural Science Foundation of China (NSFC) ( 41876125 : Gao; 41906119 : Zhang C.; 21677038 : Zhang Y.), NSFC and Royal Society travel grant ( 4141101141 : Gao and Shi), NSFC-Shandong Joint Fund ( U1906215 : Gao), Major State Basic Research Development Program of China (973 Program) ( 2014CB953701 : Gao). Shi is also supported by the Natural Environment Research Council ( NE/S00579X/1 ). We thank the open research cruise NORC2015-05 supported by NSFC Shiptime Sharing Project (project number: 41449905 ) for supporting the microcosm incubation experiments. Publisher Copyright: © 2021 Elsevier B.V.

Details

Original languageEnglish
Article number145488
Number of pages11
JournalScience of the Total Environment
Volume769
Early online date30 Jan 2021
Publication statusPublished - 15 May 2021

Keywords

  • Incubation experiment, Nitrogen deposition, Northwest Pacific Ocean, Phytoplankton, Ship emissions