EarthArXiv (California Digital Library),
Journal Year:
2022,
Volume and Issue:
unknown
Published: June 30, 2022
Seagrass
beds
offer
unique
and
vital
ecological
services
as
an
important
blue
carbon
ecosystem
in
coastal
wetlands.
Zostera
japonica
is
intertidal
seagrass
species
native
to
eastern
Asia
one
of
the
most
widely
distributed
China.
However,
little
known
on
long-term
variations
Z.
extents.
Automatic
mapping
method
for
urgent
need
fill
this
knowledge
gap.
In
study,
we
proposed
a
new
SeaGrass
Index
(SGI)
automatic
rapid
based
time-series
Landsat
satellite
imagery,
aiming
alleviate
influence
tidal
inundation
enhance
separability
from
other
cover
types.
The
SGI
considers
both
spectral
phenological
characteristics
japonica,
well
spatial
location
japonica.
We
took
Yellow
River
Delta
(YRD),
China
our
study
area,
where
was
first
discovered
reported
2015.
Based
SGI,
extents
during
1985-2018
were
extracted
using
multi-Otsu
thresholding
algorithm.
Accuracy
assessments
field
investigations
high-resolution
imagery
showed
that
has
successfully
separated
types,
especially
salt
marshes,
with
overall
accuracies
>95%,
producer’s
>90%
user’s
>94%.
Our
provides
maps
YRD.
area
large
1985-2018,
ranging
149
ha
2005-2006
1302.9
2011-2012.
distribution
varied
morphological
change
estuary
caused
by
river
channel
shifts.
Since
2011,
have
undergone
degradation
due
invasion
S.
alterniflora.
only
332.3
2017-2018.
Coastal
erosion
extreme
climate
events
such
drought
typhoon
might
also
explain
expect
will
advance
methods
beds,
provide
baseline
data
restoration
management
seagrasses
at
regional
scale.
Earth-Science Reviews,
Journal Year:
2023,
Volume and Issue:
243, P. 104501 - 104501
Published: July 13, 2023
Blue
carbon
ecosystems
(mangroves,
seagrasses
and
saltmarshes)
are
highly
productive
coastal
habitats,
considered
some
of
the
most
carbon-dense
on
earth.
They
an
important
nature-based
solution
for
both
climate
change
mitigation
adaptation.
Quantifying
blue
stocks
assessing
their
dynamics
at
large
scales
through
remote
sensing
remains
challenging
due
to
difficulties
cloud
coverage,
spectral,
spatial
temporal
limitations
multispectral
sensors
speckle
noise
synthetic
aperture
radar
(SAR).
Recent
advances
in
airborne
space-borne
SAR
imagery
Light
Detection
Ranging
(LiDAR)
data,
sensor
platforms
such
as
unmanned
aerial
vehicles
(UAVs),
combined
with
novel
machine
learning
techniques
have
offered
different
users
a
wide-range
spatial,
multi-temporal
information
quantifying
from
space.
However,
number
challenges
posed
by
various
traits
atmospheric
correction,
water
penetration,
column
transparency
issues
environments,
multi-dimensionality
size
LiDAR
limitation
training
samples,
backscattering
mechanisms
acquisition
process.
As
result,
existing
methodologies
face
major
accurately
estimating
using
these
datasets.
In
this
context,
emerging
innovative
artificial
intelligence
often
required
robustness
reliability
estimates,
particularly
those
open-source
software
signal
processing
regression
tasks.
This
review
provides
overview
Earth
Observation
state-of-the-art
deep
that
currently
being
used
quantify
above-ground
carbon,
below-ground
soil
mangroves,
saltmarshes
ecosystems.
Some
key
future
directions
potential
use
data
fusion
advanced
learning,
metaheuristic
optimisation
also
highlighted.
summary,
quantification
approaches
holds
great
contributing
global
efforts
towards
mitigating
protecting
Remote Sensing,
Journal Year:
2024,
Volume and Issue:
16(3), P. 446 - 446
Published: Jan. 23, 2024
Since
1971,
remote
sensing
techniques
have
been
used
to
map
and
monitor
phenomena
parameters
of
the
coastal
zone.
However,
updated
reviews
only
considered
one
phenomenon,
parameter,
data
source,
platform,
or
geographic
region.
No
review
has
offered
an
overview
that
can
be
accurately
mapped
monitored
with
data.
This
systematic
was
performed
achieve
this
purpose.
A
total
15,141
papers
published
from
January
2021
June
2023
were
identified.
The
1475
most
cited
screened,
502
eligible
included.
Web
Science
Scopus
databases
searched
using
all
possible
combinations
between
two
groups
keywords:
geographical
names
in
areas
platforms.
demonstrated
that,
date,
many
(103)
(39)
(e.g.,
coastline
land
use
cover
changes,
climate
change,
urban
sprawl).
Moreover,
authors
validated
91%
retrieved
parameters,
39
1158
times
(88%
combined
together
other
parameters),
75%
over
time,
69%
several
compared
results
each
available
products.
They
obtained
48%
different
methods,
their
17%
GIS
model
techniques.
In
conclusion,
addressed
requirements
needed
more
effectively
analyze
employing
integrated
approaches:
they
data,
merged
Ecological Informatics,
Journal Year:
2024,
Volume and Issue:
82, P. 102685 - 102685
Published: June 12, 2024
Seagrass
meadows
play
a
vital
role
for
lagoon
ecosystems
and
their
biota,
sustaining
multiple
ecosystem
services.
Their
distribution
functioning
are
closely
tied
to
the
environmental
pressures
induced
by
global
changes.
Long-term
monitoring
of
seagrass
species
communities
is,
hence,
important
depict
response
past
future
scenarios.
The
availability
long
term
open-access
satellite
data
offers
new
remote
sensing
perspective
dynamics
in
shallow
waters,
especially
when
combined
with
machine
learning
algorithms.
In
this
study,
seasonal
multispectral
images
(from
1999
2019)
were
collected
from
Landsat
5
Thematic
Mapper
8
Operational
Land
Imager
satellites
map
meadows,
at
community
levels,
within
vast
Grado
Marano
(Northeast
Italy)
using
Random
Forest
(RF)
algorithm.
RF
models
calculated
an
extensive
field
training
dataset
2010
(n
=
426)
reached
overall
accuracy
0.92
0.76
classification
respectively.
change
detection
analysis
revealed
increase
14.16
km2
(+
39%)
whole
cover
over
period,
rate
1.59
km2year−1.
Despite
coarse
spatial
resolution
(30
m)
Landsat's
images,
seagrasses
level
achieved
good
(0.76),
evidencing
Nanozostera
noltei
as
highest
(+13.87
time
period).
observed
expansion
is
likely
caused
sea
water
influence
that
radically
modifying
Adriatic
brackish
bodies,
emphasizing
connection
between
ongoing
changes
rapid
responses
meadows.
Journal of Environmental Management,
Journal Year:
2023,
Volume and Issue:
337, P. 117669 - 117669
Published: March 24, 2023
Seagrasses
have
been
widely
recognized
for
their
ecosystem
services,
but
traditional
seagrass
monitoring
approaches
emphasizing
ground
and
aerial
observations
are
costly,
time-consuming,
lack
standardization
across
datasets.
This
study
leveraged
satellite
imagery
from
Maxar's
WorldView-2
WorldView-3
high
spatial
resolution,
commercial
platforms
to
provide
a
consistent
classification
approach
at
eleven
areas
the
continental
United
States,
representing
geographically,
ecologically,
climatically
diverse
regions.
A
single
image
was
selected
each
of
correspond
temporally
reference
data
coverage
classified
into
four
general
classes:
land,
seagrass,
no
data.
Satellite-derived
then
compared
using
either
balanced
agreement,
Mann-Whitney
U
test,
or
Kruskal-Wallis
depending
on
format
used
comparison.
Balanced
agreement
ranged
58%
86%,
with
better
between
reference-
satellite-indicated
absence
(specificity
88%
100%)
than
presence
(sensitivity
17%
73%).
Results
tests
demonstrated
that
percentage
cover
had
moderate
large
correlations
reference-indicated
cover,
indicative
strong
Satellite
performed
best
in
dense,
continuous
sparse,
discontinuous
provided
suitable
representation
distribution
within
area.
demonstrates
same
methods
can
be
applied
scenes
spanning
varying
bioregions,
atmospheric
conditions,
optical
water
types,
which
is
significant
step
toward
developing
consistent,
operational
mapping
national
global
scales.
Accompanying
this
manuscript
instructional
videos
describing
processing
workflow,
including
acquisition,
processing,
classification.
These
may
serve
as
management
tool
complement
field-
aerial-based
efforts
ecosystems.
Landscape Ecology,
Journal Year:
2023,
Volume and Issue:
38(12), P. 4419 - 4437
Published: June 16, 2023
Abstract
Context
Seagrass
ecosystems
are
lauded
for
storing
organic
carbon
in
underlying
sediments,
but
storage
is
highly
variable,
even
at
relatively
small
spatial
scales.
While
environmental
setting
and
seagrass
cover
known
drivers
of
capacity,
it
unclear
how
other
features
such
as
species
composition
influence
storage,
whether
historical
vs.
contemporary
better
predictors
storage.
Objectives
We
examined
the
variables
on
surface
(0–10
cm)
sediment
meadow-scale
(~
25
km
2
),
addition
to
drivers.
Our
study
area
was
located
within
a
subtropical
mixed-species
meadow
along
low-energy
coastline
northeastern
Gulf
Mexico
(Cedar
Key,
Florida,
USA).
Methods
derived
metrics
from
14-year
monitoring
datasets
measured
densities
grain
size,
biomass
composition,
well
characteristics
related
hydrology
physical
disturbance
(i.e.,
relative
exposure,
elevation,
distance
navigation
channels).
assessed
bivariate
relationships
between
predictor
with
linear
regression
analyses
used
path
analysis
assess
hypothesized
subset
densities.
Results
low
global
values,
Cedar
Key
meadows
varied
by
an
order
magnitude.
Sediment
size
strongly
densities,
had
only
indirect
effects
Historical
cover,
variability
diversity
were
generally
than
variables.
identity–specifically
presence
Thalassia
testudinum
–were
also
significant
Conclusions
In
historically
diverse
persistent
dominated
late-successional
contained
largest
stores.
results
highlight
importance
site
history
terms
stability
(inversely
cover)
identity
enhancing
The
we
comparatively
weak
however,
exposure
elevation
may
not
be
most
relevant
hydrological
scale.
Together,
these
findings
suggest
that
context
scale
dependent.
Frontiers in Marine Science,
Journal Year:
2022,
Volume and Issue:
9
Published: Dec. 9, 2022
The
physical
and
ecological
importance
of
seagrass
meadows
in
coastal
processes
is
widely
recognized,
the
development
tools
facilitating
characterization
their
structure
distribution
important
for
improving
our
understanding
these
processes.
Mixed
(multi-specific)
a
Mexican
Caribbean
reef
lagoon
were
mapped
employing
multiparameter
approach,
using
PlanetScope
remote
sensing
images,
supervised
classification
based
on
parameters
related
to
seagrasses
meadows,
including
cover
percentages
seagrass/algae/sediment,
algae
thalli
shoot
densities,
canopy
heights
estimated
leaf
area
index
(LAI).
cover,
obtained
ground
truth
sampling,
while
LAI
was
data
from
long-term
monitoring
programs.
maps
do
not
show
differentiation
species,
but
truthing
contemplated
density
Thalassia
testudinum,
Syringodium
filiforme
Halodule
wrightii
respective
LAIs.
S.
dominant
species
terms
density,
T.
testudinum
LAI.
In
multiparameter-based
map
four
classes
defined,
structural
characteristics,
its
overall
accuracy
very
high
(~90%).
Maps
sediment
alone
also
had
4
classes,
they
less
accurate
than
(~70%
~80%,
respectively).
provided
spatially-explicit
abundance
seagrasses,
useful
future
changes
studies
that
require
large-scale
meadow
structure,
such
as
inventories
associated
biota,
blue
carbon
storage,
or
modelling
local
hydrodynamics.