Effect of temperature on the accumulation of marine biogenic gels in the surface microlayer near the outlet of nuclear power plants and adjacent areas in the Daya Bay, China

PLoS One. 2018 Jun 11;13(6):e0198735. doi: 10.1371/journal.pone.0198735. eCollection 2018.

Abstract

The surface microlayer (SML) in marine systems is often characterized by an enrichment of biogenic, gel-like particles, such as the polysaccharide-containing transparent exopolymer particles (TEP) and the protein-containing Coomassie stainable particles (CSP). This study investigated the distribution of TEP and CSP, in the SML and underlying water, as well as their bio-physical controlling factors in Daya Bay, an area impacted by warm discharge from two Nuclear power plants (Npp's) and aquaculture during a research cruise in July 2014. The SML had higher proportions of cyanobacteria and of pico-size Chl a contrast to the underlayer water, particularly at the nearest outlet station characterized by higher temperature. Diatoms, dinoflagellates and chlorophyll a were depleted in the SML. Both CSP and TEP abundance and total area were enriched in the SML relative to the underlying water, with enrichment factors (EFs) of 1.5-3.4 for CSP numbers and 1.32-3.2 for TEP numbers. Although TEP and CSP showed highest concentration in the region where high productivity and high nutrient concertation were observed, EFs of gels and of dissolved organic carbon (DOC) and dissolved acidic polysaccharide (> 1 kDa), exhibited higher values near the outlet of the Npp's than in the adjacent waters. The positive relation between EF's of gels and temperature and the enrichment of cyanobacteria in the SML may be indicative of future conditions in a warmer ocean, suggesting potential effects on adjusting phytoplankton community, biogenic element cycling and air-sea exchange processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / analysis
  • China
  • Chlorophyll A / analysis
  • Cyanobacteria / drug effects
  • Cyanobacteria / growth & development
  • Gels / chemistry*
  • Nuclear Power Plants
  • Oxygen / analysis
  • Phytoplankton / growth & development
  • Phytoplankton / metabolism
  • Polysaccharides / metabolism
  • Polysaccharides / pharmacology
  • Principal Component Analysis
  • Seawater / chemistry*
  • Seawater / microbiology
  • Synechococcus / growth & development
  • Synechococcus / isolation & purification
  • Temperature

Substances

  • Gels
  • Polysaccharides
  • Carbon
  • Oxygen
  • Chlorophyll A

Grants and funding

This study was supported by Special Fund for Public Welfare Research and Capacity Building in Guangdong Province(2016A020222018), National Natural Science Foundation of China (CN41106106 and No. 41430966), the National Key Research and Development Plan (No. 2017FY100700) and China Scholarship Council 201408440016.