Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Environment and Ecology, Ministry of Education of China, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Sciences, Pilot National Laboratory for Marine Science and Technology, Qingdao 266071, China.
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B152TT, UK.
Sci Total Environ. 2021 May 15;769:145488. doi: 10.1016/j.scitotenv.2021.145488. Epub 2021 Jan 30.
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 (P) 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 (NO) emissions from shipping contributed ~43% of the atmospheric N deposition flux in the NWPO. Air emissions from shipping (e.g. NO 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 P in surface seawater calculated by modeling results and World Ocean Atlas 2013 nutrient dataset, and the well-established quantitative relationship between Chl a and P 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.
随着海上交通的快速发展，航运产生的空气排放物增加，加剧了许多环境问题，包括空气污染和气候变化。然而，这些排放物对海洋生物地球化学的影响仍知之甚少。在这里，我们使用船上排放测试系统从重油动力船的烟囱中收集船舶排放颗粒（SEP），并研究了 SEP 对西北太平洋（NWPO）浮游植物生长的影响。在不同营养状态的海洋区进行的 SEP 微宇宙实验中，浮游植物的反应（以叶绿素 a (Chl a) 表示）随着 SEP 衍生氮（N）相对于基础海水中 N 储量（P）的比例增加而增加，这表明 SEP 通常通过 N 施肥促进浮游植物生长。使用空气质量模型结合船舶排放清单进行的模拟进一步表明，航运产生的氧化氮（NO）排放约占 NWPO 大气 N 沉积通量的 43%。航运产生的空气污染物（如 NO 和二氧化硫）也间接增加了大气中存在的还原 N 的沉积，占大气 N 沉积通量的约 15%。这些结果表明，空运船舶排放对大气 N 沉积的影响与 NWPO 陆地排放相当。基于模型结果和 2013 年世界海洋图集营养数据集计算的表层海水中由船舶引起的 P，以及从微宇宙实验中获得的 Chl a 和 P 之间的定量关系，我们发现由于 NWPO 海洋交通引起的 N 沉积，特别是在黄海和公海的沿海水域，表面 Chl a 浓度发生了明显变化。这项工作试图在海洋生产力和航运空气排放物之间建立直接联系。
