North American Journal of Fisheries Management,
Год журнала:
2023,
Номер
43(6), С. 1673 - 1686
Опубликована: Ноя. 7, 2023
Abstract
Objective
In
recent
decades,
widespread
evidence
of
declining
Walleye
Sander
vitreus
recruitment
in
the
Midwestern
United
States
has
raised
concerns
about
diminishing
ecological
benefits
and
fishing
opportunities,
which
turn
resulted
natural
resource
agencies
using
stocking
to
supplement
populations.
Success
events
vary;
thus,
evaluating
external
factors
that
influence
success
resulting
from
or
production
is
critical
for
improved
management.
Methods
We
evaluated
influencing
relative
98
lakes
stocked
annually
with
by
integrating
20
years
data
fisheries
assessment
abiotic
data.
indexed
as
abundance
cohorts
sources
combined
used
boosted
regression
tree
modeling
identify
variables
are
associated
varying
recruitment.
Result
Growing
degree‐days
at
age
1,
shoreline
development
index,
mean
depth,
2
were
most
important
variables.
The
model
explained
17%
observed
variability
A
positive
relationship
between
growing
was
observed,
whereas
lake
depth
had
a
negative
Secondarily
predictors
surface
area,
spring
warming
rate,
Northern
Pike
Esox
lucius
abundance,
0.
general,
positively
these
predictors,
exceptions
rates
>0.3°C/day
being
exposed
>3500
Conclusion
Our
results
indicate
thermal
addition
characteristics
drivers
waters
highlights
potential
managers
use
this
information
prioritize
efforts
temperate
lakes.
Fisheries Management and Ecology,
Год журнала:
2022,
Номер
29(4), С. 392 - 408
Опубликована: Май 27, 2022
Abstract
Ojibwe
Tribes'
approach
to
the
natural
world
is
guided
by
original
treaties
between
beings
(species
and
spirits)
people
who
reside
in
lands
now
known
as
United
States
Canada.
Relationships
with
these
beings,
such
ogaa
(walleye
Sander
vitreus
),
are
best
characterised
taking
care
of
a
relative/gift
for
next
seven
generations
Ojibwe.
Initial
denial
treaty
rights
state
government
has
strongly
influenced
tribes'
relationship
their
relatives
over
100
years.
Ogaa
stocks
reproduction
have
declined
Minocqua
Chain
Lakes
(Wisconsin,
USA)
last
20
Region‐wide
declines
been
attributed
many
stressors
overharvest
state‐licensed
anglers,
invasive
species
climate
change.
Here,
we
retroactively
applied
resist–accept–direct
(RAD)
framework
process
used
create
an
interjurisdictional
rehabilitation
plan
Lakes.
Specifically,
cover
following:
progress
date
on
plan;
subsistence,
cultural
spiritual
challenges
associated
resisting
ecosystem
change;
unforeseen
obstacles
rehabilitation;
re‐evaluation
ogaa;
unknowns;
contingency
plans
from
tribal
perspective.
Lastly,
discuss
how
RAD
could
become
more
useful
tribes
region.
Canadian Journal of Fisheries and Aquatic Sciences,
Год журнала:
2024,
Номер
81(12), С. 1650 - 1665
Опубликована: Авг. 1, 2024
Managing
fisheries
in
a
changing
socio-ecological
environment
may
require
holistic
approaches
for
identifying
and
adapting
to
novel
ecosystem
dynamics.
Using
32
years
of
Ceded
Territory
Wisconsin
(CTWI)
walleye
(
Sander
vitreus)
data,
we
estimated
production
P),
biomass
B),
turnover
P/B),
yield
Y),
over
Y/P)
tested
hyperstability
yield.
Most
CTWI
populations
showed
low
P
B,
Y/P
<
1
.
Yet,
overharvest
>
1)
was
prevalent
among
recruitment-based
management
(natural
recruitment
(NR),
sustained
only
by
stocking,
combination).
Production,
P/B
have
declined
NR
populations,
while
Y
remained
constant.
Walleye
hyperstable
along
gradient
all
fishery
types
(i.e.,
angling
only,
angling/tribal
harvest
combined).
Diminishing
productivity
be
jointly
contributing
observed
declines.
We
classified
lakes
into
groups
low,
moderate,
or
high
vulnerability
based
on
dynamics
identify
that
benefit
from
declines
maintain
increase
the
adaptive
capacity
walleye.
Canadian Journal of Fisheries and Aquatic Sciences,
Год журнала:
2023,
Номер
80(2), С. 273 - 286
Опубликована: Янв. 10, 2023
Walleye
(
Sander
vitreus)
are
an
ecologically
important
species
managed
for
recreational,
tribal,
and
commercial
harvest.
prefer
cool
water
low
light
conditions,
therefore
changing
temperature
clarity
potentially
impacts
walleye
habitat
populations
across
the
landscape.
Using
survey
data
collected
from
1993
to
2018
312
lakes
in
Minnesota,
we
evaluated
relationship
between
thermal-optical
relative
abundance
of
small
(0–300
mm),
medium
(300–450
large
(450
+
mm)
walleye.
Thermal-optical
was
positively
correlated
with
but
not
were
more
abundant
larger,
naturally
reproducing
opposed
smaller,
stocked
lakes.
changed
59%
since
1980
(26%
increasing
33%
decreasing)
appears
be
driven
primarily
by
changes
thus
optical
area.
Our
study
provides
insights
into
local
regional
drivers
that
influence
can
used
assist
fisheries
managers
setting
population
goals
managing
Abstract
Climate
change
is
a
complex
threat
to
freshwater
ecosystems.
Effects
on
aquatic
species
will
likely
differ
among
populations
depending
seasonal
and
spatial
context,
which
makes
detailed
understanding
of
population
responses
shifting
climate
conditions
key
guiding
strategic
decision‐making.
However,
few
empirical
studies
have
tested
for
such
context
dependency
distinct
across
seasons
or
at
large
scales.
We
used
26
years
standardized
survey
data
recreationally
economically
important
brook
trout
(
Salvelinus
fontinalis
)
brown
Salmo
trutta
in
Wisconsin,
USA
assess
short‐
long‐term
variability
trends,
quantify
the
influence
(air
temperatures
precipitation)
annual
recruitment
strength
(as
indexed
by
young‐of‐year
[YOY]
relative
abundance
summer).
Some
short‐term
fluctuations
were
spatially
consistent
state,
indicative
broadscale
environmental
forcing.
Over
longer
term,
average
YOY
age
1
older
has
declined
since
2006,
especially
YOY,
while
substantially
increased.
The
effects
varied
species,
season,
latitude.
Increasing
maximum
summer
associated
with
lower
recruitment,
but
higher
recruitment.
effect
both
was
stronger
latitudes.
Spring
positively
related
latitudes;
mid‐latitude
northern
streams,
they
increasing
up
about
standard
deviation,
above
declined.
High
low
winter
spring
precipitation
precipitous
declines
species.
By
contrast,
streams
southern
trout.
Our
results
demonstrate
that
shifts
can
affect
similar
differently
temporal
(seasonal)
(warm,
regions
compared
cool,
regions)
context.
Given
trends
Wisconsin
projections
Midwestern
United
States,
location‐
species‐specific
management
actions
are
needed
account
this
dependency.
Management
should
aim
maximize
resiliency
extreme
buffering
negative
influences
North American Journal of Fisheries Management,
Год журнала:
2023,
Номер
43(3), С. 656 - 676
Опубликована: Фев. 6, 2023
Abstract
Muskellunge
Esox
masquinongy
,
Northern
Pike
E.
lucius
Walleye
Sander
vitreus
and
Largemouth
Bass
Micropterus
salmoides
are
popular
sport
fish
that
often
co‐occur
in
aquatic
systems.
Although
numerous
studies
have
investigated
interactions
among
these
species,
the
simultaneous
evaluation
of
diet
patterns
niche
overlap
all
four
species
has
not
been
conducted.
Our
experimental
design
aimed
to
quantify
other
piscivores,
while
lakes
without
were
also
sampled
compare
diets
piscivores
their
presence
or
absence.
Diets
from
10
Minnesota
collected
via
gastric
lavage
quantified
using
an
index
relative
importance.
individual
compared
seasons
predator
length
categories,
among‐species
comparisons
conducted
by
season
permutational
multivariate
ANOVA
(PERMANOVA).
consumed
a
wide
range
prey,
whereas
consisted
primarily
Yellow
Perch
Perca
flavescens
centrarchids.
more
invertebrates,
especially
crayfish
Faxonius
spp.
No
exhibited
seasonal
shifts,
but
different
categories
for
except
Walleye.
nonmetric
multidimensional
scaling
ordinations
indicated
shared
prey
use,
PERMANOVA
results
most
each
piscivores'
across
seasons.
Conversely,
similar
regardless
presence.
Finally,
lake‐scale
habitat
variables
correlated
with
piscivore
diets,
abundance
was
diets.
indicate
Muskellunge,
Pike,
Walleye,
can
coexist
variety
lakes,
populations
important
should
be
examined
before
management
actions
(e.g.,
stocking)
implemented
ensure
adequate
availability
competition
is
increased
detriment
existing
fisheries.
