Nitrogen subsidies to pelagic food webs through profundal methane-oxidising bacteria in oligotrophic fresh water
Journal
Freshwater Biology
Journal Volume
2024
Pages
1–13
Date Issued
2024-02-22
Author(s)
dela Paz, Erica Silk P.
Okuda, Noboru
Lin, Fan Sian
Lai, Chao Chen
Fujibayash, Megumu
Shiah, Fuh Kwo
Abstract
Nutrient subsidy of methane-oxidising bacteria (MOB), an alternative basal resource, to plankton communities through pelagic-benthic coupling is expected to alter carbon-to-nitrogen (C/N) ratios and biomass of zooplankton, and affect biological processes in aquatic food webs. Previous studies indicate that most MOB nutrient subsidies to zooplankton are focused largely on C subsidies; nevertheless, considering that N is important to zooplankton and phytoplankton growth, a better understanding of MOB N subsidies to plankton communities is needed. We examined changes in nutrients, phytoplankton mass-specific productivity, MOB reliance, C/N ratios and biomass of zooplankton between summer stratification and winter mixing periods based on in situ investigation in a subtropical deep oligotrophic freshwater ecosystem during 2010–2014. The results revealed that with increasing reliance on MOB during the winter mixing period, zooplankton C/N ratios decreased and had a significantly nonlinearly inverse relationship with zooplankton biomass. The negative relationship between zooplankton biomass and phytoplankton mass-specific productivity was further observed in synchronous time. The profundal MOB enhanced pelagic-profundal coupling and served as an alternative N support for pelagic plankton food webs during the winter and/or less productive seasons, adding to greater understanding of the role of methanotrophs in aquatic food webs.
Subjects
freshwater | methane-oxidising bacteria | nutrient subsidy | phytoplankton | zooplankton
Publisher
John Wiley and Sons Inc
Type
journal article