Does competition for nitrogen between autotrophs and heterotrophs control carbon fluxes in the western coastal Arctic?
Acronym: OCB-051 Program: Ocean Carbon & Biogeochemistry [OCB] URL: Start date: 2009-09 End date: 2012-08 Geolocation: Description: Unds are provided to investigate the microbial controls on the productivity of a coastal Arctic ecosystem by focusing on the competition between autotrophs and heterotrophs for nitrogen (N). In the winter and summer waters near Barrow, Alaska, supplemented with complementary international research opportunities, the PIs propose to measure in situ concentrations of key microbial and biogeochemical constituents, relevant uptake activities, and expression of key N cycling genes to address two hypotheses: H1: The balance of autotrophy and heterotrophy in the Arctic is regulated both temporally and spatially by nitrate (NO3ˉ) and light. ? Phytoplankton out-compete heterotrophic bacteria for NO3ˉ during the well-lit spring and summer conditions. ? Heterotrophic bacterial uptake of NO3ˉ will be greater during the dark winter and under sea ice than in open wate
