Highly mobile pelagic species co‐occur with fine‐scale ocean fronts
Limnology and Oceanography,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 23, 2025
Abstract
Coastal
areas
are
an
important
source
of
food
and
a
valuable
tourism
asset
for
communities,
but
also
highly
dynamic
heterogeneous
environments.
Understanding
how
marine
species
respond
to
the
variability
their
habitat
is
essential
sustainably
manage
coastal
resources.
Here
we
investigate
distribution
mobile
in
relation
fine‐scale
fronts
(<
10
km)
North‐East
Aotearoa
New
Zealand.
We
use
fishery
dependent
catch
aerial
observations
assess
compare
locations
position
tracked
using
high‐resolution
ocean
color
images.
find
significant
aggregation
near
surface
chlorophyll
most
considered.
Specifically
blue
mackerel,
kahawai,
jack
mackerel
often
found
regions
moderate
high
characterized
by
strong
spatial
gradients
color.
On
other
hand,
seabirds
mammals
collocated
with
higher
concentrations
lower
compared
examined.
These
findings
advance
our
understanding
interact
fronts,
suggesting
that
these
features
need
be
accounted
explicitly
modeling
effective
management.
Язык: Английский
Testing spatial transferability of species distribution models reveals differing habitat preferences for an endangered delphinid (Cephalorhynchus hectori) in Aotearoa, New Zealand
Ecology and Evolution,
Год журнала:
2024,
Номер
14(7)
Опубликована: Июль 1, 2024
Abstract
Species
distribution
models
(SDMs)
can
be
used
to
predict
distributions
in
novel
times
or
space
(termed
transferability)
and
fill
knowledge
gaps
for
areas
that
are
data
poor.
In
conservation,
this
determine
the
extent
of
spatial
protection
required.
To
understand
how
well
a
model
transfers
spatially,
it
needs
independently
tested,
using
from
habitats.
Here,
we
test
transferability
SDMs
Hector's
dolphin
(
Cephalorhynchus
hectori
),
culturally
important
(taonga)
endangered,
coastal
delphinid,
endemic
Aotearoa
New
Zealand.
We
collected
summer
three
populations
2021
2023.
Using
Generalised
Additive
Models,
built
presence/absence
each
population
validated
predictive
ability
top
(with
TSS
AUC).
Then,
tested
by
predicting
remaining
two
populations.
showed
useful
performance
within
their
respective
(Banks
Peninsula
Otago),
but
when
outside
models'
source
data,
declined
markedly.
third
area
(Timaru)
performed
poorly,
both
prediction
transferred
spatially.
When
building
were
combined
areas,
results
mixed.
Model
interpolation
was
better
Otago,
an
low
density,
with
higher
otherwise
The
overall
poor
suggests
habitat
preferences
dolphins
vary
between
areas.
For
these
dolphins,
population‐specific
should
conservation
planning.
More
generally,
demonstrate
one
fits
all
approach
is
not
always
suitable.
data‐poor
assessment
new
required,
interpreted
caution.
Язык: Английский
Who lives in the open sea? Distribution and densities of surfacing marine megafauna in three subregions of the South Pacific (New Caledonia, Wallis and Futuna, and French Polynesia)
Pacific Conservation Biology,
Год журнала:
2023,
Номер
30(1)
Опубликована: Дек. 18, 2023
Context
Assessing
the
distribution
and
abundance
of
marine
fauna
ecological
status
coastal
pelagic
ecosystems
is
key
to
biodiversity
conservation,
but
monitoring
mobile
species
raises
multiple
logistical
financial
challenges.
Aims
The
project
describes
distribution,
taxonomic
assemblage
several
megafauna
taxa
in
three
subregions
western
central
South
Pacific
Ocean
(New
Caledonia,
Wallis
Futuna,
French
Polynesia).
Methods
Large-scale
aerial
surveys
were
conducted
using
a
standardised
multi-taxon
protocol,
characterise
occurrence
over
2.5
million
km2.
Analysing
more
than
122
000
km
transects,
densities
22
different
estimated:
seven
groups
mammals
(Physeteridae,
Kogiidae,
Ziphiidae,
Globicephalinae,
Small
Delphininae,
Large
Dugongidae),
single
group
for
hard-shelled
sea
turtles,
elasmobranchs
(including
whale
sharks),
11
seabirds
Phaethontidae,
Hydrobatidae,
Fregatidae
Sulidae).
Key
results
Contrasting
patterns
found.
Marine
mammal
diversity
increases
north
west,
with
distinct
New
compared
other
subregions.
A
strong
latitudinal
gradient
was
observed
across
Polynesia,
independent
taxa.
Conclusions
This
study
provides
first
comparison
assemblages
oceanic
sets
regional
baseline
biogeography
region.
Implications
spatial
extension
opens
up
new
perspectives
development
local
conservation
measures,
especially
already
documented
population
declines.
Язык: Английский
Evidence of environmental niche separation between threatened mobulid rays in Aotearoa New Zealand: Insights from species distribution modelling
Journal of Biogeography,
Год журнала:
2024,
Номер
51(11), С. 2117 - 2135
Опубликована: Июль 4, 2024
Abstract
Aim
Mobulid
rays
are
a
group
of
threatened
batoid
fishes
susceptible
to
population
decline
from
targeted
fisheries
and
accidental
capture.
Spatial
distributions
mobulid
remain
poorly
known.
Prior
studies
found
commonalities
between
favourable
environments
prey
among
various
species,
yet
most
were
conducted
in
tropical
waters.
To
explore
the
habitat
use
distribution
temperate
environment
we
model
suitability
two
(
Mobula
mobular
birostris
)
Aotearoa
New
Zealand
using
citizen
science
occurrence
data
spanning
almost
decades.
Location
Northeastern
coast
Aotearoa,
Zealand.
Methods
Boosted
Regression
Tree
models
used
predict
annual
environmental
conditions
species
based
on
available
sightings
records
conjunction
with
high
resolution
(1
km
2
data.
Results
The
sympatric
study
had
contrasting
requirements.
We
separation
their
spatial
defined
by
200
m
isobath
–
onshore
extent
for
M.
offshore
.
While
there
only
subtle
variations
relative
over
period,
exhibited
greater
interannual
variability.
Despite
differing
patterns,
separation,
as
function
properties,
persisted
regardless
year.
Main
Conclusions
Our
results
suggest
that
associations
may
differ
regions
due
regional
adaptations
availability
or
local
unique
colder
more
productive
findings
highlight
importance
multi‐species
surveys
inclusion
temporal
variability
support
separate
species‐specific
management
plans
account
stressors
impacting
each
species.
Язык: Английский
Estimating abundance of a small population of Bryde's whales: a comparison between aerial surveys and boat‐based platforms of opportunity
Animal Conservation,
Год журнала:
2023,
Номер
27(4), С. 426 - 436
Опубликована: Дек. 26, 2023
Abstract
Accurate
abundance
estimates
are
essential
for
the
development
of
effective
conservation
management
strategies,
yet
they
difficult
to
produce
small
populations
that
elusive
and
sparsely
distributed
throughout
their
range.
For
such
it
is
challenging
collect
a
representative
dataset
sufficient
robust
estimation
detectability
abundance.
Over
one‐year
study,
we
used
two
methods
estimate
Nationally
Critical,
widely
dispersed
Bryde's
whale
population
in
Hauraki
Gulf,
Aotearoa/New
Zealand;
(i)
distance
sampling
from
systematic
line‐transect
aerial
surveys
(
n
=
22
surveys,
9,944
km,
total
sightings
21–24
whales),
(ii)
mark‐recapture
(MR)
using
photo‐identification
images
collected
platform‐of‐opportunity
small‐boat
(218
occasions,
27
whales).
From
estimated
an
average
15
whales
(95%
CI
6,
30;
CV
37%)
at
sea‐surface
any
time.
boat‐based
developed
custom
MR
model
address
seasonal
individual
heterogeneity
capture
probabilities
obtained
72
distinct
38,
106;
24%)
population.
These
approaches
provide
different
perspectives
on
dynamics
whales.
The
number
individuals
present
one
time,
whereas
animals
Gulf
during
study.
Although
neither
method
optimal
estimating
this
small,
population,
use
complementary
informs
managers
about
patterns
distribution
over
temporal
spatial
scales.
It
common
have
limited
resources
marine
research
where
assumptions
cannot
be
met.
Here,
highlight
pragmatic
strategies
showing
how
models
can
customized
interest
assist
with
monitoring
species
concern.
Язык: Английский