Data from: Microbial metabolic activity in two basins of the Gulf of Mexico influenced by mesoscale structures

Information on microbial metabolic activity is essential for quantifying
carbon and energy flows through marine food webs. We quantified community
(Rcom) and prokaryotic (Rpro) respiration rates, bacterial production
(BP), bacterial abundance (BA), and bacterial growth efficiencies (BGE) in
the Perdido and Coatzacoalcos basins of the Gulf of Mexico (GOM) during
summer and winter conditions in 2016. Our results showed seasonal,
regional, and mesoscale eddy influences on those metabolic variables. Rpro
accounted for more than 60% of total respiration in both regions, being
three times higher in stations influenced by a cyclonic eddy (CE) in
September (24.1 μM O2 d-1) than in stations affected by an anticyclonic
eddy in March (7.2 μM O2 d-1) within the Coatzacoalcos basin where the
eddy-trapping mechanism advected biomass-enriched waters from the Bay of
Campeche. The eddy-stirring mechanism produced horizontal and vertical
dipole patterns of metabolic variables increasing up to one order of
magnitude Rcom and Rpro while decreasing BGE to 25-fold from the
southeastern to the northwestern edges in CEs. This finding indicates that
dissolved organic matter is more actively taken up to build bacterial
biomass on the eastern edge of CEs in the GOM, while respiration rates
increase on the western edges. Satellite integrated primary production was
coupled with surface respiration rates at CEs and no eddies. Bacterial
production was mainly regulated by CEs and was about 50% higher in the
Coatzacoalcos basin (~0.03–0.14 µmol C L-1 d-1). BP increased in zones
with high respiration rates, suggesting that Rcom is associated with
heterotrophic prokaryote activity in both basins. Bacterial growth
efficiency was lower than 25% within the upper 500 m during both cruises,
but the highest values were quantified in the euphotic zone and during the
September cruise. Metabolic variables integrated over the water column
showed that 40–80% of the activity occurred between the base of the
euphotic zone and 150 m depth. Our findings contribute to a better
understanding of the metabolic activity of the microbial communities in
two regions of the GOM influenced by mesoscale eddies.