M O D E L I N G L A K E M I C H I G A N ’S SU I TABI LI TY FO R
ASIAN CARP INVASIONS of notorious
they compose 63 percent
1) Does Lake Michigan have
different food throughout
non-native species like the
of the total fish biomass.
enough food to support bighead
the water column. The data
sea lamprey and dreissenid
Bigheaded carp disrupt aquatic
and silver carp? 2) How do
produced by a 3D lake model
mussels have transformed
food webs by voraciously
human-caused stressors such
allowed the team to build on
the Great Lakes ecosystem.
feeding on zooplankton and
as climate change and nutrient
previous research by evaluating
As efforts to understand
phytoplankton, which limits
pollution affect Lake Michigan’s
subsurface habitats while also
and minimize the damage of
the food available to resident
vulnerability to bigheaded carp?
accounting for bigheaded carp’s
already entrenched invaders
fishes. Bigheaded carp will
continue, the prevention of
also consume alternative
new invasions has become a
foods, such as detritus and
strategic priority of invasive
bacteria, when plankton
species management. Of the
becomes less available.
many species being monitored by scientists, perhaps none are more concerning than Asian carp.
6
To help answer these questions, a team of scientists from CIGLR, NOAA GLERL, the University of
ability to feed on an alternative prey item, detritus, as well as phytoplankton and zooplankton.
Michigan and Eureka Aquatic
Their results were surprising.
Research constructed a model
By accounting for diet flexibility
The close proximity of
that evaluates Lake Michigan’s
and subsurface habitat in the
bigheaded carp to Lake
suitability for bigheaded carp
model, the research team
Michigan has elevated
growth. The work was part
demonstrated that nearly all
concerns about the impact they
of CIGLR Ecological Modeling
of Lake Michigan contains
Bighead and silver carp
could have on the Great Lakes
Data Analyst Peter Alsip’s
suitable habitat for bigheaded
(collectively referred to as
food web, which supports a
master’s thesis at the University
carp. Habitats with greatest
bigheaded carp) are the two
$7 billion recreational fishery.
of Michigan School for
potential to support bigheaded
plankton-feeding species
While their insatiable appetites,
Environment and Sustainability.
carp were located near river
of Asian carp that were
flexible diets, rapid growth,
The team’s approach (known
mouths and in Green Bay,
imported to the United
and reproduction rates make
as a “growth rate potential
which agrees with previous
States in the 1970s as a
bigheaded carp a formidable
model”) measures habitat
studies. However, their research
means of controlling algal
invader, Lake Michigan is colder
quality based on water
also demonstrates that Lake
growth in reservoirs and
and has less plankton than
temperature, prey abundance,
Michigan’s offshore areas are
sewage treatment lagoons.
the environments where they
and bigheaded carp’s
suitable for bigheaded carp.
These species escaped into
currently exist. Reductions in
physiological requirements
Although offshore areas offer
natural waterways, quickly
nutrient loads over the past
for growth. Previous studies
a relatively low-quality habitat,
spreading throughout the
50 years and the proliferation
indicated that bigheaded carp
making them less appealing
Mississippi River basin.
of the invasive filter-feeding
could only survive in Lake
for resident populations, they
Bigheaded carp have
quagga mussels have
Michigan’s plankton-dense
may provide migration corridors
established dense populations
transformed Lake Michigan
areas, such as Green Bay, but
through which bigheaded carp
in many rivers, including
into a plankton desert, which
these studies did not account
could spread to more food-rich
the Illinois River where
has prompted two questions:
for carp feeding flexibly on
areas in the lake.
