Influences of the hydrophilic components of two anthropogenic dissolved organic nitrogen groups on phytoplankton growth in Jiaozhou Bay, China

Rui Yang; Shanqiao Chen; Xiansheng Zhang; Rongguo Su; Chuansong Zhang; Shengkang Liang; Xiurong Han; Xiulin Wang; Keqiang Li

doi:10.1016/j.marpolbul.2021.112551

Influences of the hydrophilic components of two anthropogenic dissolved organic nitrogen groups on phytoplankton growth in Jiaozhou Bay, China

Mar Pollut Bull. 2021 Aug:169:112551. doi: 10.1016/j.marpolbul.2021.112551. Epub 2021 Jun 16.

Authors

Rui Yang¹, Shanqiao Chen¹, Xiansheng Zhang¹, Rongguo Su², Chuansong Zhang², Shengkang Liang³, Xiurong Han², Xiulin Wang², Keqiang Li⁴

Affiliations

¹ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
² College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
³ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
⁴ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China. Electronic address: likeqiang@ouc.edu.cn.

PMID: 34119960
DOI: 10.1016/j.marpolbul.2021.112551

Abstract

Increasing human activities have caused the accumulation of dissolved organic nitrogen (DON) in the ocean, which can alter dominant coastal phytoplankton species. However, insights into DON's effects on marine phytoplankton growth are insufficient compared with those of dissolved inorganic nitrogen (DIN), especially regarding the role of specific DON components. Therefore, in this study, the effects of the hydrophilic (Hic) and low molecular weight (LMW) components of two anthropogenic DON sources on the growth and bioavailable nitrogen uptake of phytoplankton were studied using in situ cultural experiments conducted in Jiaozhou Bay, China. Animal-derived DON from domestic and livestock breeding showed a higher bioavailability compared with that of vegetal DON derived from agricultural sources, with bioavailable component proportions of 76% ± 4% and 66% ± 3%, respectively. Both forms of DON could be absorbed by Skeletonema costatum, stimulating it to become the dominant species in the mesocosm ecosystem; the hydrophilic components of DON contributed approximately 75% of the uptake of DON by S. costatum. The bioavailability of LMW DON was significantly (p < 0.05) lower than that of the Hic DON. The high bioavailability of the Hic DON was mainly associated with its protein-like T1 and T2 components, identified using parallel factor analysis on the excitation-emission-matrix spectra, while the low bioavailability of LMW DON was mainly associated with the humus-like A component. The protein-like T2 components may be directly absorbed by algae, while T1 may be transformed through mineralization and algal absorption. Understanding the impacts of anthropogenic DON and its components on phytoplankton will help improve coastal environmental management. More knowledge of the effect of anthropogenic DON on the phytoplankton community structure in coastal waters should be accumulated in the future.

Keywords: Bioavailability; Coastal water; Dissolved organic nitrogen; Hydrophilic component; Phytoplankton.

MeSH terms

Animals
Bays*
China
Ecosystem
Humans
Nitrogen / analysis
Phytoplankton*

Substances

Nitrogen