Frontiers in Marine Science,
Год журнала:
2022,
Номер
9
Опубликована: Март 24, 2022
The
Yellow
Sea
(YS)
is
an
epicontinental
sea
framed
by
the
densely
populated
mainland
of
China
and
Korean
peninsula.
Human
activities
over
last
decades
resulted
in
heavily
increasing
discharge
reactive
nitrogen
into
YS,
which
created
numerous
ecological
problems.
To
elucidate
role
central
YS
cycling
nitrogen,
specifically
Cold
Water
Mass
(YSCWM),
we
determined
nutrient
concentrations,
dual
stable
isotopes
nitrate
(δ
15
N-
NO3-
δ
18
O-
id="INEQ2">NO3-
),
particulate
sedimentary
spring
summer,
i.e.,
biologically
inactive
active
periods.
concentration
was
higher
than
that
summer
northern
part
YSCWM,
Nitrate
increased
southern
accompanied
a
decrease
id="INEQ3">NO3-
id="INEQ4">NO3-
,
are
indicative
nitrification
significant
source
recycled
south
YSCWM.
quantify
this
regenerated
nitrate,
use
mixing
model
with
end
members
preformed
both
their
distinct
isotope
values.
results
suggest
only
35%
residual
65%
branch
YSCWM
regenerated.
has
low
concentrations
dissolved
inorganic
mainly
because
denitrification
sediments.
In
contrast,
pool
growing
reservoir
terrestrial
addition
compensates
removal
co-occurring
sediment
denitrification.
consequence,
facing
risk
branch,
when
excess
from
Changjiang
River
continues
at
present
levels
or
even
increases.
Communications Earth & Environment,
Год журнала:
2024,
Номер
5(1)
Опубликована: Май 7, 2024
Abstract
The
world
is
experiencing
an
increase
in
the
frequency
and
intensity
of
extreme
weather
events,
yet
influences
remote
inland
events
on
coastal
ecosystem
thousands
kilometers
away
remain
poorly
understood.
Here
we
tracked
chain
ecological
effects
rainfall
event
North
China
from
terrestrial
rivers
to
aquaculture
area
eastern
Shandong
Peninsula.
Our
data
suggest
autumn
flood
resulted
leads
abnormally
low
turbidity
Coastal
Currents
red
tide
blooms
by
introducing
anomalous
freshwater
with
exceptionally
high
nitrogen-to-phosphorus
ratio
into
Bohai
Sea.
Lower
salinity,
stronger
light
conditions
caused
limpid
currents,
phosphorus
limitation
resulting
account
for
huge
kelp
loss
offshore
This
study
underscores
importance
considering
multidisciplinary
observation
risk
management
unexpected
events.
Frontiers in Marine Science,
Год журнала:
2025,
Номер
11
Опубликована: Янв. 30, 2025
Research
on
phytoplankton
distribution
and
dynamics
is
crucial
for
understanding
marine
ecosystem
functions
evaluating
their
status.
The
northern
Yellow
Sea
(NYS),
a
marginal
sea
of
the
Pacific
Ocean,
has
experienced
significant
anthropogenic
impacts
since
late
20
th
century,
resulting
in
an
increased
nitrogen-to-phosphorus
(N/P)
ratio
heightened
phosphorus
limitation.
These
changes
are
considered
critical
factors
affecting
community
structure
NYS
over
recent
decades.
This
study
analyzed
temporal
environmental
during
summers
from
2011
to
2020,
aiming
elucidate
driving
forces.
results
indicated
decrease
dissolved
inorganic
nitrogen
(DIN)
concentration
after
2011,
decreased
N/P
ratio,
while
limitation
persisted.
Temperature,
temperature
gradient
(reflecting
stratification
intensity)
salinity
exhibited
upward
trends,
whereas
pH,
nitrogen-to-silicon
(N/Si)
chlorophyll-
showed
downward
trends.
abundances
total
phytoplankton,
Bacillariophyta,
Dinoflagellata,
as
well
Dia/Dino
index,
fluctuated
annually
correlated
with
temperature,
gradient,
nutrient
structure.
Diversity
indices
remained
stable
throughout
period.
Cold
Water
Mass
prominently
influenced
summer
structure,
exhibiting
lower
abundance,
species
richness
cold
water
mass
region,
where
adaptable
such
Tripos
muelleri
Paralia
sulcata
predominated.
Our
emphasized
impact
associated
climate
change,
including
rising
temperatures,
salinity,
enhanced
stratification,
years,
particularly
concerning
dominant
composition
index.
Therefore,
ongoing
attention
effects
change
coastal
environments
communities
essential.
Journal of Geophysical Research Biogeosciences,
Год журнала:
2022,
Номер
127(5)
Опубликована: Апрель 20, 2022
Abstract
Dual
isotope
measurements
were
performed
on
nitrate
(δ
15
N‐NO
3
−
and
δ
18
O‐NO
)
in
the
Pearl
River
Estuary
(PRE)
adjacent
northern
South
China
Sea
(NSCS)
to
investigate
sources
its
biogeochemical
processes
during
rainy
season.
Our
results
indicated
that
PRE,
high
levels
associated
with
intense
human
activities
PRE
delta,
of
which
included
reduced
nitrogen
(N)
fertilizer
(29%),
SN
(nitrate
derived
from
soil
N)
(18%),
manure
sewage
(10%),
atmospheric
deposition
(7%).
In
nearshore
area,
was
characterized
by
relatively
values
suggestive
incomplete
assimilation.
Besides,
nitrification
might
be
significant
intermediate
bottom
waters
due
ammonia
release
remineralization
sinking
sedimented
organic
matter
(OM).
offshore
depleted
nearly
complete
utilization,
showed
moderate
values.
addition,
exhibited
a
clear
vertical
gradient
decrease
surface
bottom.
A
coupled
nitrification‐denitrification
process
sediment
porewater
supposed,
left
imprints
area.
although
assimilation
prominent
process,
relationship
deviated
1:1
line,
suggesting
contribution
increased
offshore.
study
suggests
external
source
shifts
anthropogenic
continuous
river–estuary–ocean
system,
become
more
active
as
it
goes
seaward.
