Ecological Indicators,
Journal Year:
2023,
Volume and Issue:
155, P. 110959 - 110959
Published: Sept. 27, 2023
The
proliferation
of
algal
blooms
can
lead
to
environmental
issues.
phytoplankton
responsible
for
these
are
diverse.
Different
species
bloom-forming
algae
have
distinct
characteristics
and
hazards,
therefore
need
different
treatment
methods.
An
accurate
quick
determination
the
spatial
temporal
distribution
is
crucial
lake
ecological
restoration.
Based
on
differences
in
remote
sensing
reflectance
(Rrs)
various
typical
eutrophic
lakes
(including
Microcystis
aeruginosa,
Aphanizomenon
sp.,
Pseudanabaena
sp.
Cyanobacteria
Chlorella
Scenedesmus
quadricauda
Chlorophytes),
difference
index
distinguishing
were
developed
differentiate
species.
A
validation,
using
an
independent
dataset
from
indoor
experiment
in-situ-measured
satellite-image-derived
Rrs,
showed
that
algorithm
provide
reliable
results
(overall
accuracies
81.97%,
81.25%,
60.42%,
respectively).
According
Ocean
Land
Color
Instrument
images
Lake
Taihu
period
2016
2020,
was
dominant
algae,
followed
by
Aphanizomenon.
dominance
two
types
Chlorophytes
less
pronounced.
proportion
as
highest
summer,
while
peaked
winter.
varied
slightly
throughout
year,
In
terms
distribution,
patterns
spring
autumn
relatively
similar.
approximately
80%
dominated
Microcystis.
winter,
more
prevalent
along
southeastern
shore
Taihu.
construction
application
this
model
a
technical
support
prediction
prevention
inland
lakes.
The Science of The Total Environment,
Journal Year:
2024,
Volume and Issue:
932, P. 172741 - 172741
Published: April 26, 2024
Cyanobacteria
are
major
contributors
to
algal
blooms
in
inland
waters,
threatening
ecosystem
function
and
water
uses,
especially
when
toxin-producing
strains
dominate.
Here,
we
examine
140
hyperspectral
(HS)
images
of
five
representatives
the
widespread,
potentially
bloom-forming
genera
Microcystis,
Planktothrix,
Aphanizomenon,
Chrysosporum
Dolichospermum,
determine
potential
utilizing
visible
near-infrared
(VIS/NIR)
reflectance
for
their
discrimination.
Cultures
were
grown
under
various
light
nutrient
conditions
induce
a
wide
range
pigment
spectral
variability,
mimicking
variations
found
natural
environments.
Importantly,
assumed
simplified
scenario
where
all
variability
was
derived
from
cyanobacteria.
Throughout
cyanobacterial
life
cycle,
multiple
HS
acquired
along
with
extractions
chlorophyll
phycocyanin.
Images
calibrated
average
spectra
region
interest
extracted
using
k-means
algorithm.
The
data
pre-processed
seven
methods
subsequent
integration
into
Random
Forest
models,
whose
performances
evaluated
different
metrics
on
training,
validation
testing
sets.
Successful
classification
rates
close
90
%
achieved
either
first
or
second
derivative
smoothing,
identifying
important
wavelengths
both
VIS
NIR.
Microcystis
achieving
highest
accuracy
(>95
%),
followed
by
Planktothrix
(79
finally
Dolichospermum
Aphanizomenon
(>50
%).
imagery
discriminate
among
toxic
cyanobacteria
is
discussed
context
advanced
monitoring,
aiming
enhance
remote
sensing
capabilities
risk
predictions
bodies
affected
harmful
blooms.
Remote Sensing,
Journal Year:
2025,
Volume and Issue:
17(4), P. 608 - 608
Published: Feb. 11, 2025
Harmful
algae
blooms
(HABs)
pose
critical
threats
to
aquatic
ecosystems
and
human
economies,
driven
by
their
rapid
proliferation,
oxygen
depletion
capacity,
toxin
release,
biodiversity
impacts.
These
blooms,
increasingly
exacerbated
climate
change,
compromise
water
quality
in
both
marine
freshwater
ecosystems,
significantly
affecting
life
coastal
economies
based
on
fishing
tourism
while
also
posing
serious
risks
inland
bodies.
This
article
examines
the
role
of
hyperspectral
imaging
(HSI)
monitoring
HABs.
HSI,
with
its
superior
spectral
resolution,
enables
precise
classification
mapping
diverse
species,
emerging
as
a
pivotal
tool
environmental
surveillance.
An
array
HSI
techniques,
algorithms,
deployment
platforms
are
evaluated,
analyzing
efficacy
across
varied
geographical
contexts.
Notably,
sensor-based
studies
achieved
up
90%
accuracy,
regression-based
chlorophyll-a
(Chl-a)
estimations
frequently
reaching
coefficients
determination
(R2)
above
0.80.
quantitative
findings
underscore
potential
for
robust
HAB
diagnostics
early
warning
systems.
Furthermore,
we
explore
current
limitations
future
management,
highlighting
strategic
importance
addressing
growing
economic
challenges
posed
paper
seeks
provide
comprehensive
insight
into
HSI’s
capabilities,
fostering
integration
global
strategies
against
proliferation.
Scientific Reports,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: April 16, 2025
Abstract
Hyperspectral
sensing
of
phytoplankton,
free-living
microscopic
photosynthetic
organisms,
offers
a
comprehensive
and
scalable
method
for
assessing
water
quality
monitoring
changes
in
aquatic
ecosystems.
However,
unmixing
the
intrinsic
optical
properties
phytoplankton
from
hyperspectral
data
is
complex
challenge.
This
research
addresses
problem
non-linear
absorbance
concentrated
samples
using
Blind
(BAE)
Endmember
Guided
Autoencoder
(EGAE).
We
show
that
spectral
EGAE
model
with
different
objective
functions
can
effectively
estimate
abundance
components
data.
The
demonstrated
higher
correlation
between
unmixed
endmember
abundances
ground
truth
chlorophyll-a
(chl-a)
fucoxanthin
(fx)
biomarker
pigment
concentrations
compared
to
BAE
model,
spectrum
cyanobacterial
phycocyanin
(pc)
was
robust
network
architecture.
It
adaptively
unmix
various
endmembers
without
impacting
estimates
other
pigments.
Our
results
demonstrate
provided
stable
improved
accuracy
reliability
identifying
quantifying
pigments,
allowing
more
precise
into
their
constituent
endmembers.
anticipate
our
study
will
serve
as
starting
point
targeted
specific
pigments
EGAE.
Phycology,
Journal Year:
2025,
Volume and Issue:
5(2), P. 16 - 16
Published: April 30, 2025
Reservoirs
and
downstream
rivers
draining
Oregon’s
Cascade
Range
provide
critical
water
supplies
for
over
1.5
million
residents
in
dozens
of
communities.
These
waters
also
support
planktonic
benthic
cyanobacteria
that
produce
cyanotoxins
may
degrade
quality
drinking,
recreation,
aquatic
life,
other
beneficial
uses.
This
2016–2020
survey
examined
the
sources
transport
four
cyanotoxins—microcystins,
cylindrospermopsins,
anatoxins,
saxitoxins—in
six
river
systems
feeding
18
drinking
treatment
plants
(DWTPs)
northwestern
Oregon.
Benthic
cyanobacteria,
plankton
net
tows,
(or)
Solid-Phase
Adsorption
Toxin
Tracking
(SPATT)
samples
were
collected
from
65
sites,
including
tributaries,
reservoirs,
main
stems,
sites
at
or
upstream
DWTPs.
Concentrated
extracts
(320
samples)
analyzed
with
enzyme-linked
immuno-sorbent
assays
(ELISA),
resulting
>90%
detection.
(n
=
80)
mostly
Nostoc,
Phormidium,
Microcoleus,
Oscillatoria,
yielded
microcystins
(76%
detection),
cylindrospermopsins
(41%),
anatoxins
(45%),
saxitoxins
(39%).
Plankton
tow
tributaries
stems
94)
contained
(84%),
(77%),
(25%),
(22%),
revealing
their
seston.
SPATT
sampler
146)
(81%),
(66%),
(37%),
(32%),
indicating
presence
dissolved
water.
Reservoir
15),
most
often
containing
Dolichospermum,
(87%),
(73%),
(47%),
but
no
saxitoxins.
The
high
detection
frequencies
DWTP
intakes,
popular
where
salmon
steelhead
continue
to
exist,
highlight
need
additional
study
on
these
factors
promote
production
cyanotoxins,
minimize
effects
humans,
ecosystems,
economies.
Ecological Indicators,
Journal Year:
2024,
Volume and Issue:
162, P. 111970 - 111970
Published: April 26, 2024
The
spatiotemporal
distribution
of
harmful
algal
blooms
(HABs)
in
rivers
remains
poorly
understood,
and
there
is
an
urgent
need
to
develop
a
consistent
set
metrics
better
document
HAB
occurrences
forecast
future
events.
Using
data
from
seven
sites
the
Illinois
River
Basin,
we
computed
focused
on
conditions
related
excess
growth
hypoxia.
Daily
mean
chlorophyll
dissolved
oxygen
(DO)
concentrations,
gross
primary
productivity
(GPP),
net
ecosystem
(NEP)
rates,
water
quality
status,
identifying
timing
transition
clear-water
dominated
state.
Early
warning
indicators
(EWIs),
first-order
autoregressive
process
(Ar1)
standard
deviation
(SD)
events,
forecasting
blooms.
Metrics
were
compared
either
literature-derived
or
statistical-based
thresholds
normalized
by
total
number
daily
samples
for
exceedance
rate.
Exceedances
concentration
averaged
50
%
across
all
using
10
µg
L−1
threshold
but
increasing
μg
reduced
average
rate
5
%.
GPP
(∼8
g
O2
m2d−1
threshold)
was
15
%,
similar
amplitude
DO
(∼3
mg
threshold),
NEP
(0
m2
d−1
higher,
at
28
days
with
least
1
continuous
below
5,
3,
2
L−1,
had
basin
wide
rates
9
3
respectively.
Thresholds
EWIs,
Ar1
SD,
exceeded
7
high
concentrations
rates.
correlation
between
proxies
biomass
(chlorophyll
concentration)
(GPP)
strongest
middle
region
basin,
R2
values
0.54
0.74.
Although,
cyanotoxin
are
most
commonly
used
states
define
inland
HAB,
paucity
publicly
available
data.
wider
availability
combined
results
this
study
suggest
that
state
event-based
may
be
promising
way
assess
predict
vulnerability
some
deleterious
effects
HABs
broad
spatial
scales.