Cyanobacterial distributions along a physico‐chemical gradient in the N ortheastern P acific O cean
Summary The cyanobacteria P rochlorococcus and S ynechococcus are important marine primary producers. We explored their distributions and covariance along a physico‐chemical gradient from coastal to open ocean waters in the N ortheastern P acific O cean. An inter‐annual pattern was delineated in the...
Saved in:
Published in | Environmental microbiology Vol. 17; no. 10; pp. 3692 - 3707 |
---|---|
Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
01.10.2015
|
Online Access | Get full text |
Cover
Loading…
Summary: | Summary
The cyanobacteria
P
rochlorococcus
and
S
ynechococcus
are important marine primary producers. We explored their distributions and covariance along a physico‐chemical gradient from coastal to open ocean waters in the
N
ortheastern
P
acific
O
cean. An inter‐annual pattern was delineated in the dynamic transition zone where upwelled and eastern boundary current waters mix, and two new
S
ynechococcus
clades, Eastern Pacific Clade (
EPC
) 1 and
EPC2
, were identified. By applying state‐of‐the‐art phylogenetic analysis tools to bar‐coded
16S
amplicon datasets, we observed higher abundance of
P
rochlorococcus
high‐light I (
HLI
) and low‐light I (
LLI
) in years when more oligotrophic water intruded farther inshore, while under stronger upwelling
S
ynechococcus
I
and
IV
dominated. However, contributions of some cyanobacterial clades were proportionally relatively constant, e.g.
S
ynechococcus
EPC2
. In addition to supporting observations that
P
rochlorococcus
LLI
thrive at higher irradiances than other
LL
taxa, the results suggest
LLI
tolerate lower temperatures than previously reported. The phylogenetic precision of our
16S rRNA
gene analytical approach and depth of bar‐coded sequencing also facilitated detection of clades at low abundance in unexpected places. These include
P
rochlorococcus
at the coast and
C
yanobium‐
related sequences offshore, although it remains unclear whether these came from resident or potentially advected cells. Our study enhances understanding of cyanobacterial distributions in an ecologically important eastern boundary system. |
---|---|
ISSN: | 1462-2912 1462-2920 |
DOI: | 10.1111/1462-2920.12742 |