Download Integrated Pest Management of Invasive Fish: Common Carp

Integrated Pest Management of
Invasive Fish:
Common Carp
Peter W. Sorensen, Przemek Bajer & Lab
University of Minnesota
Dept. of Fisheries, Wildlife, and Conservation Biol.
This Talk
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Invasive Fish
Integrated Pest Management
The sea lamprey
Introduction to the common carp
Integrated, sustainable control
An hypothesis and approach
An example in North American Midwest
Questions?
The world’s ‘worst’ invasive fishes
4.
1.
4
.
2.
5.
3.
6
North America
Conventional Control

Toxins/ draw-downs/ trapping (mass mortality)
Rotenone
TFM
Often unsustainable, damaging (nontargeted)
 Often not possible (ex. Asian carp)

Integrated Pest Management (IPM)
Control of a species using a collection of techniques
that target specific biological attributes in
an economically, socially and ecologically viable
manner that is sustainable over the long-term.
-Specialized biochemistry and physiology
-Mechanistic behaviors and life histories
-Short generation times
Integrated control of fish
(2 species)
The sea lamprey
Sea lamprey invasion triggered collapse of the Great
Lakes fisheries…
Lake Superior
Percent of Historic Average Abundance
140
120
100
80
60
40
?
20
0
1930
1940
1950
1960
1970
Year
lamprey
enter lake
wild lake trout - MI
1980
1990
Life History
Early focus on barriers
Herculean Search
for larvicide
•
•
6000+ compounds tested
3-trifluoromethyl-4-nitrophenol (TFM ) found
Deployment of Lampricides
$1.5 million for treatments each year
$3 million assessment
Search for an integrated program
??
New traps
Sterile males
??
Population Models
New Poisoning Techniques
New barriers
Summary: Sea Lamprey Control
1. Complex mix, designed to enhance TFM
2. An open system but a simple and ‘unusual’
creature.
3. A qualified success
Many native fish have returned
 BUT Costs high
 TFM is still the backbone.

The common carp
-a teleost
-oviparous
-long-lived
-physiologically resilient
A fish from shallow seas in central Asia…
Invasion Perpetuated by Man
The Romans
Catholic Church
U.S. Fish Commissionstocking
Australia
Fish farming
Global but especially damaging in a few places
Adult carp destroy habitats and water quality
‘Biological pump’
Algae bloom
Nutrients (N, P)
X
Shading
Plants
decline
Uprooting
Damaging to Plants, Waterfowl and Fish
Hennepin-Hoper Lakes, IL after carp invasion
Carp
Biomass
2004
10 kg/ha
2006
100 kg/ha
2008
250 kg/ha
Extant Control Techniques
-Mix of unselective removal & exclusion techniques
-Expensive, usually unsustainable
- VARIABLE RESULTS
Adult
Seining
seining
Rotenone
Drawdowns
Water Draw-downs
Electrical Barriers
Carp seperation cages
Integrated Carp Management
in Tasmania
A Closed population in a sensitive lake with low biodiversity
Adult removal and spawning sabotage
‘Judas males’ to capture aggregations
Spawning sabotage using traps and lime
10 years, 2 million dollars
Now down to few females…
Monthly carp captures from Lake Crescent February 1995 - November 2003
550
500
450
Total of 7753 carp removed and processed. Population estimates
Number of processed carp
400
350
300
250
200
150
100
50
0
than 20 f emales remain
Summary: Carp in Tasmania
Simple, clever combination
 A closed system with sensitive species
 Qualified success

Suppressed but not extirpated
 No poisons used
 What if they are introduced again
 Very expensive

Integrated Control of Carp in
Minnesota , 2005Overarching goal:
‘To develop biologically and economically sound
plans for controlling carp in MN lakes over the
long-term by exploiting its life history*’
* not known!
Initial Sub-Objectives
1.Do carp use pheromones, and might they be useful?
2.Do carp have specific aggregate for spawning or
other reasons and might they be targeted?
3. Is carp abundance attributable to specific factors
that might be targeted (population dynamics*)?
* Models but shockingly little data!
1. Pheromones
Chemical signals that pass between organisms of the same
species (Karlson & Luscher 1959, Sorensen & Wyatt 2000).
O
O
ßOH
OH
O
O
O
O
O
S
O
OH
Mean number of fish in the range (+SE)
Female PGF pheromone attracts carp to
traps in the field (Li & Sorensen)
OH
3
COOH
Implant
OH
Blank
P = 0.01
O
2
1
0
10
20
30
Distance from a trap (m)
Sorensen and Li, unpublished
50
Mean distance from a trap
• Implant: 28.97 ± 2.80 m (N = 27)
• Blank: 38.54 ± 2.19 m (N = 12)
P < 0.01
2. Spawning, can it or other
aggregations be sabotaged?
Radio-tracking 80 adult carp during spawning season in a
system of interconnected lakes and marshes
Weak spawning site preferences
(and strong propensity to migrate and then return)
Spawning sabotage not reasonable
19
31
2
7
0
7
31
Bajer & Sorensen (2010)
Aggregations in Winter
(targetable?)
3. Why are there so many carp?
(and can we do something about it)
Numbers
Ages
ABUNDANCE
Lake
Sampling
sessions Marked
Recaps
Population
Estimate
(95% CI)
Dutch
11
122
13,312
2088
Biomass
(kg/ha)
371*
(11,300 – 16,100)
Echo
13
929
72
5,666
326
(4,605 - 7,361 )
Susan
11
361
15
4,459
307
(5,700-3,661)
*150 kg/ha is considered damaging
Recruitment: highly sporadic in MN
Susan &
Marsh
winterkill
Marsh
Marsh
winterkills winterkills
Removal of carp and BH
2500
2000
1500
1000
?
?
500
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
0
1988
Number of carp
Marsh
winterkills
Bajer and Sorensen; Biol Invasions 2009
Why winterkill?
Lakes that winterkill are unstable, lack
predators that otherwise eat carp eggs and
larvae….
Summer-time unstable nursery habitats
(Australia)
Test-1: Carpsim shows winterkill can explicitly
explain the densities we measure
> 200 / net
> 130 / net
YOY carp present
No YOY carp present
Test-3: When we stock lakes with fertilized
carp eggs, eggs are eaten in normoxic lakes
but NOT normoxic lakes (PB)
% Survival to hatch day
90
80
70
normoxic
60
hypoxic
50
40
30
20
10
0
Open
Control
Coarse mesh
A Model of Invasiveness
Recruits?
Nursery
Susan
Marsh
Recruits?
Adult Refuge
Adult Refuge
Riley
Bajer and Sorensen 2010
Integrated Carp Control in MN
I. Diagnosis problem and establish goals
II. Treat carp based on Population Dynamics
a. Remove a critical number of adults
b. Suppress recruitment (and/or spawning)
c. Suppress emigration (if necessary)
III. Monitor and Model
IV. Adapt
A ‘Typical’ Example:
Riley Creek Chain of Lakes
Lucy
ANN
SUSAN
RICE MARSH
RILEY
http://www.bwsr.state.mn.us/publications/WD_Guidebook/RileyPurgatory.pdf
1. Targeted removal of adult carp: Judas fish
2008 – population estimated: 4,181 carp (Lake Susan)
January 2009 – Judas fish

3278 removed (78%)
January 2010

183 removed
April 2010


138 removed (at the carp barrier)
590 remain in the lake (15% of original)
2. ‘Monitoring’ fish movement
(with an aim to controlling recruitment)
Construct simple ($100) fish gate to ensure no carp movement
3. Monitor and Suppress Recruitment
Aerate nursery, encourage game-fish, monitor
RESULTS: Carp Abundance
So far, effective + no signs of recruitment…
Carp movement is predictable and stoppable
22
50
20
Rain event
18
40
30
12
10
20
8
Carp
Pike
Temperature
Depth (cm)
10
6
4
2
0
0
4.
1.
20
09
4.
7.
20
09
4.
14
.2
00
9
4.
21
.2
00
9
4.
28
.2
00
9
5.
05
.2
00
9
5.
12
.2
00
9
5.
19
.2
00
9
5.
27
.2
00
9.
6.
01
.2
00
9
Count
14
Date
Temperature
16
Results: Aquatic vegetation recovered
Vegetative cover %
70.00
60.00
2008 removal
Before
50.00
After
2009removal
40.00
30.00
20.00
10.00
0.00
0
0.5
1
1.5
2
Depth
2.5
3
3.5
Results: Water clarity improvements in L. Susan
2008
2009
5
4.5
2010
3.5
3
2.5
2
1.5
Before removal
1
0.5
15-Oct
1-Oct
17-Sep
3-Sep
20-Aug
6-Aug
23-Jul
9-Jul
25-Jun
11-Jun
28-May
14-May
0
30-Apr
Water Clarity (m)
4
Sources: MPCA, UofM
Integrated Pest Management in Minnesota
1. Three components (at present):
-recruitment, immigration, adult removal
2. Works well in moderate sized, semi-closed lakes
3. A success (so far):
- Large sustainable drop in carp density
- Substantial increase in water quality
- No poisons
- Affordable
- Well received
4. Could be improved and expanded… (barely touched)
5. The common carp system is suitable for experiments
SUMMARY:
1. IPM can work!
2. It likely must focus on recruitment, density
dependence.
3. It will be situation specific (species, locale, scales)
4. Solid biological foundation is still needed
5. Modeling is useful esp. if good data exists
6. It can /should set the stage for more sophisticated and
diverse techniques such as genetic control.
FUNDING
Riley Purgatory Bluff Creek Watershed District
Ramsey Washington Metro Watershed District
YOY carp
adult carp
black
bullhead
green sunfish
yellow perch
70
northern pike
largemouth
bass
black crappie
bluegill
sunfish
Average (+- SE) catch per trap net
Test-2: ‘We’ now often find age-0 carp in hypoxic lakes,
but never in normoxic lakes (PB)
Hypoxic N=12
Normoxic N=13
60
50
40
30
20
10
0
Removal of carp in Lake Riley

94% population removed using Judas fish on 3/5/10
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
Number of carp
3500
14
3000
12
2500
10
2000
8
1500
6
1000
4
500
2
0
0
Winter dissolved oxygen (mg/L)
Recruitment following winterkill is common
(ex. Lake Echo)
TREATING: Riley Chain of Lakes
Emigration
Immigration*
monitor
Recruitment*
Population*
Growth
Prevent/ control winterkill
to enhance predation*
MORTALITY!
Egg sac resorption
Hatching
Spawning
* = Monitor
2) However, not all carp need be removed?
(to improve water quality)
L. Susan!
?
Hennepin Hoper Lakes, IL, USA
Is 100 kg carp /ha a
threshold for severe
damage in shallow lakes?
Bajer et al. 2009
Lake Keller (refuge lake with Bluegills)
RESULTS:
- eggs ‘disappear’ within 3 days (prior to
hatch)
- 1000’s of eggs in bluegill sunfish guts
Vegetation
Stomach
50
45
40
35
30
25
20
15
10
5
0
300
250
200
150
100
# Eggs in
Stomach
18.3° C
50
0
1
2
3
4
5
6
Day after Spawning
Mean count
Avg # Eggs
in 100g
Vegetation
Bluegill Predation
in Lake Keller
500
450
400
350
300
250
200
150
100
50
Keller Lake Trap Catch
10
8
6
4
2
Yellow perch
Pike
Pumpkinseed
Bass
Goldfish
Hybrid sunfish
Green sunfish
Crappie
Fathead minnow
Adult Carp
Young Carp
Bluegill
- SUMMER: No young carp found in Lake
Bullhead
0
Population Dynamics!
Emigration
Immigration
Recruitment*
Population
Growth
Mortality
* Survival of fertilized eggs to adulthood
Egg sac resorbtion
Hatching
Spawning
A dashed line signifies intermittency
1. Remove a critical targeted number of adult carp
Winter seining – Lake Susan


Tracked carp aggregation in January under ice n corner
Seined and removed 3278 carp, over 20,000 lbs (78% of population)
Biomass reduced from 307 lbs/acre to 90 lbs/acre
Water quality

Clear
water
Turbid water
Reduction in carp biomass
Many ways to control abundance
(the best will address the local situation)
Emigration
Immigration
Recruitment*
Population
Growth
MORTALITY
Egg sac resorbtion
Hatching
Spawning
1. Remove Critical Number of Adult Carp
Winter 2008/2009:
-78% of the population in Lake Susan
- 35% of population from Lake Riley
Winter/summer 2009, repeat at critical level:
- Ongoing
2. Control winterkill effects, Phase I:

2008/2009: Temporary ($100) barriers to stop spawning carp
moving into winterkilled marsh (other fish passed)
Monitoring
Temp Barrier
Life History
Eggs
???
???
???
2. They move: Approximately 1/3 of adult carp move
in/out wetlands to spawn (ex. Riley-Susan-Marsh)
Study lakes
Study lakes
Dutch
Dog
Echo
Susan,
Rice Marsh,
Riley
# spawning act / min (mean +SE)
Olfaction plays a critical role in
carp sexual behavior
20
P < 0.01
15
10
5
0
Nose-plugged
Sham control
Male carp treated
Monitored for 1 hr
N = 7 pairs
Spawning activity
Study 1

Hypothesis: The abundance of age-0 carp will
be higher in hypoxic lakes which have lower
density of predatory fishes that forage on carp
eggs and larvae
Study Design – step 2

Mortality of carp eggs determined in 2 normoxic and 2
hypoxic lakes



2-4 Carp spawning areas located in each lake
Carp eggs attached to yarn floats
In each area we placed:
 8 in open water (fish + invertebrates)
 4 in coarse mesh bags (invertebrates only)
 4 in fine mesh controls
 Counted daily until hatching

Diet of native fishes examined in one normoxic lake
Invasive Species
‘an alien [nonnative / exotic / introduced]
species whose introduction does or is likely
to cause economic or environmental harm
or harm to human health’
(President Clinton’s - Executive Order 13112)