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.
Limnology and Oceanography,
Год журнала:
2023,
Номер
68(5), С. 1161 - 1171
Опубликована: Март 12, 2023
Abstract
Nutrient
import
into
eutrophic
estuarine‐coastal
zones
is
modulated
by
river
discharge
and
anthropogenic
activities
(agriculture,
industry,
sewage,
etc.).
Comparing
vs.
hydrological
influences
on
nutrient
loading
important
for
ecosystem
managers
but
has
been
a
long‐standing
challenge.
As
an
attempt
to
fill
this
gap,
retrospective
study
was
conducted
using
multiyear
(2012–2022)
data
in
one
of
the
most
coastal
seas
China,
Jiangsu
waters.
Of
two
main
pollutants
coast,
dissolved
inorganic
nitrogen
(DIN)
extremely
overloaded
relative
phosphate
(PO
4
).
Their
spatial
distribution
shows
clear
terrestrial
sources
as
concentrations
decrease
offshore.
Although
each
survey
DIN
PO
are
enriched
low‐salinity
waters,
their
spatially
averaged
out
phase
with
seasonal
interannual
scales.
A
box
model
applied
decompose
contributions
activities.
Results
show
that
human
impacts
variability
exceed
those
factors
coast.
Anthropogenic
decreases
during
2012–2020,
paralleled
reduced
fertilizer
use
other
nonpoint
sources.
Sporadic
fluxes
from
point
likely
responsible
aseasonal
nutrient‐rich
patches.
Our
demonstrates
water
quality
waters
highly
affected
Findings
have
broad
implications
local
monitoring
strategies
restoration
efforts
provide
insight
assessing
stress
field
global
ecosystems.
Ecology and Evolution,
Год журнала:
2024,
Номер
14(2)
Опубликована: Фев. 1, 2024
Abstract
Macroinvertebrates
play
a
vital
role
in
coastal
ecosystems
and
are
an
important
indicator
of
ecosystem
quality.
Both
anthropogenic
activity
environmental
changes
may
lead
to
significant
the
marine
macroinvertebrate
community.
However,
assembly
process
benthic
biodiversity
its
mechanism
driven
by
factors
at
large
scales
remains
unclear.
Here,
using
field
survey
data
15
years
spatial
temporal
from
Yellow
Sea
Large
Marine
Ecosystem,
we
investigated
relative
importance
selection,
dispersal
processes,
random‐deterministic
processes
macroinvertebrates
community
diversity
assembly,
responses
this
temperature
nutrients.
Results
showed
that
is
mainly
affected
dispersal.
Nitrogen
phosphorus
most
negative
among
variables,
while
geographical
distance
main
limiting
factor
β
diversity.
Within
range
0.35–0.70
mg/L
nutrients,
increasing
nutrient
concentration
can
significantly
facilitate
contribution
decay
effect
studied
(15.0–18.0°C),
both
warming
cooling
greater
tendency
for
species
be
dominated
deterministic
processes.
The
analysis
contributes
better
understanding
communities
how
they
adapt
global
biogeochemical
Water,
Год журнала:
2023,
Номер
15(7), С. 1398 - 1398
Опубликована: Апрель 4, 2023
Remote
sensing
is
widely
used
for
lake-water-quality
monitoring,
but
the
inversion
of
total
nitrogen
(TN)
and
phosphorus
(TP)
rivers
non-optical
parameters
still
a
difficult
problem.
The
use
high
spatial
temporal
resolution
multispectral
imagery
combined
with
machine
learning
techniques
an
effective
solution
this
difficulty.
Three
methods
based
on
support
vector
regression
(SVR),
neural
network
(NN)
random
forest
(RF)
were
to
invert
TN
TP
using
actual
water-quality
measurement
data
Sentine-2
remote-sensing
images,
analyzed
factors
influencing
water
quality
in
terms
pollutant
emissions
land
use.
results
show
that
RF
performs
best
both
(R2
=
0.800,
RMSE
0.640,
MSE
0.400,
MAE
0.480)
0.830,
0.033,
0.001,
0.022)
models,
optimal
selection
feature
variables
improves
model
performance.
concentrations
Minjiang
River
Meishan
Water
Function
Development
Zone
highest
downstream
section
2018.
Analysis
shows
pollution
sources
amounts
closely
related
land-use
types,
riparian
zones
at
different
scales
had
degrees
impact
quality.
Heliyon,
Год журнала:
2024,
Номер
10(7), С. e28182 - e28182
Опубликована: Март 22, 2024
Nitrogen
and
phosphorus
concentrations
in
oceans
have
been
extensively
studied,
advancements
associated
disciplines
rapidly
progressed,
enabling
the
exploration
of
novel
previously
challenging
questions.
A
keyword
analysis
was
conducted
using
Scopus
database
to
examine
chronological
trends
hotspots,
offering
comprehensive
insights
into
evolution
marine
nitrogen
research.
For
this
purpose,
author
networks
were
developed
for
periods
before
1990,
1990
2000,
2001
2011,
2012
2022.
Furthermore,
analytical
techniques
employed
recent
decade
determine
seawater
assessed
their
applicability
limitations
through
a
critical
review
more
than
50
journal
articles.
Taxonomy
biogeochemistry
prominent
research
interests
first
two
periods,
respectively,
while
stable
isotopic
tracking
processes
emerged
as
dominant
focus
last
decades.
The
integration
macroeconomic
factors
development
rise
interdisciplinary
identified.
Conventional
such
spectrophotometry,
colorimetry,
fluorometry,
elemental
noted,
along
with
emerging
like
remote
sensing
microfluidic
sensors.
Environmental Chemistry,
Год журнала:
2025,
Номер
22(1)
Опубликована: Янв. 20, 2025
Environmental
context
External
nutrients
giving
rise
to
critical
ecological
issues
of
the
coastal
seawater.
We
investigated
nearshore
nutrient
concentrations
and
their
sources
in
Xiamen
Bay
during
2013–18.
Our
results
could
provide
theoretical
support
for
controlling
pollution.
Rationale
greatly
increase
risks
Therefore,
it
is
important
understand
variation
characteristics
nitrogen
(N)
phosphorus
(P)
area.
Methodology
The
dissolved
inorganic
(DIN)
phosphate
(PO4–P)
were
monitored
from
2013
2018.
input
runoff
was
calculated
flow
amount
collected
by
Marine
Fisheries
Bureau.
Atmospheric
dry
deposition
DIN
simulated
using
Williams
model
analyse
potential
Xiamen.
Results
High
PO4–P
levels
occurred
inner
bay
decreased
dramatically
outside
Bay.
lowest
values
observed
summer,
which
consistent
with
temporal
inputs
surface
atmospheric
deposition.
Jiulong
River
main
source
eutrophication
Bay,
providing
more
than
4
×
104
tonnes
(Mg)
N
per
year.
provided
2.2
103
Mg
year,
accounts
~3.4–6.3%
Discussion
ratio
enrichment
varied
0.21
0.40,
indicating
that
an
contributor
This
study
provides
insight
into
major
P
highlights
importance
city
