Environmental Science & Technology,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 4, 2025
Hypoxia
is
observed
and
projected
to
expand
in
many
aquatic
environments,
largely
due
excess
anthropogenic
nutrient
inputs
climate
change,
thus
influencing
biogeochemical
processes.
Denitrification,
generally
an
anaerobic
process,
removes
bioavailable
nitrogen
produces
nitrous
oxide
(N2O).
However,
limited
observations
of
the
effect
oxygen
on
denitrification
restrict
our
ability
estimate
changes
amount
N2O
emissions
under
perturbations
change.
Here,
we
show
that
all
steps
increased,
while
production
yield
from
decreased
with
decreasing
Chesapeake
Bay
-
largest
estuary
United
States.
The
different
responded
similarly
Bay,
unlike
open
ocean
minimum
zones,
implications
for
accumulation
or
depletion
intermediates
such
as
nitrite
N2O.
Our
also
suggest
current
model
parametrizations
likely
overestimate
removal
presence
oxygen,
which
would
bias
evaluation
cycling,
ecosystem
productivity,
extent
hypoxia.
Overall,
newly
derived
sensitivities
could
be
used
improve
constrain
budget
estuarine
coastal
environments
experiencing
Water,
Год журнала:
2025,
Номер
17(3), С. 311 - 311
Опубликована: Янв. 23, 2025
Marine
bacterioplankton
perform
a
very
important
role
in
the
cycles
of
carbon,
nitrogen,
phosphorus,
and
other
elements
coastal
waters.
The
impacts
environmental
factors
on
bacterial
community
structure
are
dynamic
ongoing.
This
study
investigated
spatiotemporal
distributions
their
influences
communities
waters
around
Changli
Gold
Coast
National
Nature
Reserve
northern
China.
results
demonstrate
significant
temporal
variability
carbon
spring
summer,
influenced
by
natural
anthropogenic
activities.
In
spring,
increased
biological
activity,
particularly
phytoplankton
growth,
may
elevate
TOC
POC
levels
near
river
estuaries,
while
microbial
decomposition
likely
stabilized
concentrations.
seasonal
variation
was
obvious.
Bacteroidetes
were
enriched
samples
Cyanobacteriota
proliferated
summer.
dominated
genera
including
Planktomarina,
an
unclassified
NS5_marine_group
(belonging
to
Flavobacteriaceae),
OM43_clade
(Methylophilaceae),
showed
positive
correlation
with
salinity,
TDP,
TOC,
POP,
DO
levels,
Synechococcus_CC9902
(Synechococcus),
PeM15_unclassified
(Actinobacteria),
HIMB11
(Rhodobacteraceae),
which
all
dominate
summer
samples,
significantly
positively
correlated
TN,
TDN,
temperature,
ammonium
levels.
particular,
increase
human
activities
inputs
greatly
improves
nutrient
promotes
propagation
photosynthetic
microorganisms.
These
indicate
that
physical
conditions
affected
changes
activities,
have
effects
bacterioplankton.
highlights
importance
ongoing
monitoring
estuarine
areas,
especially
protected
areas
like
Reserve,
manage
eutrophication
risks
maintain
ecological
balance.
Geophysical Research Letters,
Год журнала:
2025,
Номер
52(3)
Опубликована: Янв. 30, 2025
Abstract
Widespread
anthropogenic
activities
pollute
groundwater
that
eventually
seeps
out
to
the
coastal
ocean.
Here,
we
resolve
nutrient
transformations
and
fluxes
in
11
sandy
subterranean
estuaries
(STEs)
with
contrasting
sources
development
trajectories.
Coastal
nitrogen
pollution
stems
from
sewage
discharge
land
use
change.
Anthropogenically
derived
high
N/P
ratios
(∼170)
accounted
for
22%–61%
of
riverine
inputs
into
China's
waters,
providing
an
additional
source
nutrients
can
fuel
eutrophication
algal
blooms.
Sandy
STEs
remarkably
attenuated
∼84%
pollution,
minimizing
impact
submarine
(SGD)
on
water
quality.
Hence,
deliver
overlooked
ecosystem
service
is
particularly
important
highly
polluted
aquifers.
Protecting
recognizing
integrated
nature
seawater
thus
quality
management
initiatives.
Frontiers in Marine Science,
Год журнала:
2025,
Номер
12
Опубликована: Фев. 6, 2025
Seaweed
cultivation
contributes
to
coastal
carbon
sequestration
making
it
a
compelling
strategy
mitigate
global
climate
change.
Porphyra
(commonly
known
as
nori)
is
an
economically
important
seaweed
have
high
release
rates
for
biogenic
dissolved
and
particulate
organic
matter
(DOM
POM).
However,
the
impact
of
on
dynamics
remains
unclear.
To
fill
this
knowledge
gap,
we
conducted
investigations
examining
quantity
optical
properties
DOM
POM,
microbial
community
structures
relevant
environmental
factors
along
continuum
from
subtropical
river
through
its
adjacent
zone
during
non-cultivation
periods.
Dissolved
(DOC)
concentration
was
significantly
elevated
versus
period,
while
(POC)
decreased,
thereby
resulting
in
higher
DOC/POC
ratio
water
column.
Endmember
mixing
analysis
further
suggested
that
autochthonous
dominated
both
periods,
with
limited
inputs
terrestrial
carbon.
Redundancy
revealed
more
modules
mediated
transformations
leading
169%
estuarine
addition
microbially-sourced
humic-like
C3
compared
period.
Our
findings
demonstrate
enhanced
by
promoting
production
transformation
refractory
DOM,
which
has
implications
sustainable
management
development
blue
strategies.
Frontiers in Marine Science,
Год журнала:
2025,
Номер
12
Опубликована: Март 3, 2025
The
high
primary
productivity
zone
(HPPZ)
of
estuaries
is
known
for
its
flourishing
fisheries
and
active
interactions
with
coastal
oceanic
ecosystems.
However,
the
spatiotemporal
patterns
underlying
mechanisms
that
regulate
HPPZ
remain
unclear,
especially
in
face
drastic
changes
riverine
inputs.
Using
40
years
situ
monitoring
data
along
Yangtze
River
estuary,
evolution
regulated
by
basin-estuarine-offshore
flux
fluctuations
has
been
reconstructed
past
conclusions
drawn
future
developments.
Moreover,
biological
processes
influence
formation
were
explored
within
context
estuarine
filtration
buffering
effects.
obtained
dataset
includes
chlorophyll
a
(Chl-a)
concentrations
multiple
environmental
factors.
results
displayed
characterized
annual
average
Chl-a
concentration
3.6
±
2.4
μg/L,
which
driven
sufficient
light
nutrient
availability
promote
phytoplankton
blooms.
In
contrast,
inner
turbidity
exhibits
an
1.0
0.7
primarily
due
to
limited
inhibiting
growth.
Meanwhile,
outer
lower
zone,
0.9
1.1
from
deficiencies
limit
Notably,
synergistic
effect
sediment
declines
eutrophication
resulted
6.5
μg/L
increment
HPPZ’s
3628
km²
expansion
area
extent
over
years.
This
significant
change
attributed
increase
water
transparency
resulting
reduction
transported
watershed
sea,
nitrogen
phosphorus
discharge.
A
projection,
based
on
historical
total
suspended
matter
nutrients
years,
suggests
will
reach
10.5
projected
7,904
2050.
study
presents
first
quantification
spatial
range
focusing
interaction
between
materials.
These
findings
offer
deeper
understanding
managing
ecological
risks
large
estuaries.
