Open AccessPhysical mixing in coastal waters controls and decouples nitrification via biomass dilution
Author(s) -
Sebastian Haas,
Brent M. Robicheau,
Subhadeep Rakshit,
Jennifer Tolman,
Christopher K. Algar,
Julie LaRoche,
Douglas W.R. Wallace
Publication year - 2021
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2004877118
Subject(s) - nitrification , biogeochemical cycle , water column , environmental science , nitrogen cycle , environmental chemistry , eutrophication , nitrospira , nitrate , anammox , ecology , nitrite , denitrification , chemistry , nutrient , denitrifying bacteria , biology , nitrogen , organic chemistry
Significance Changes in both quantity and speciation of nitrogen in coastal waters impact phytoplankton communities, contributing to eutrophication and harmful algal blooms. Multidisciplinary oceanographic time series of high resolution are rare but crucial for identifying complex mechanisms that underlie such anthropogenic impacts. Analysis and modeling of such a time series from a seasonally stratified fjord showed that dilution of nitrifier biomass by variable winter mixing altered the timing and rates of nitrification, which converts ammonia to nitrite and nitrate. This reveals a link among climate-sensitive physical dynamics, nitrifier abundance, and diversity, with controls on phytoplankton ecology. The findings imply that explicit measurement and modeling of microbial communities will be required to project impacts of climate change on coastal ecosystems.