Predation and Activity
Levels of the Invasive
Indo-Pacific Lionfish
in the Bahamas
Research by Emily Pickering
Advised by Dr. Mark Hixon,
Mark Albins, & Tim Pusack,
OSU Zoology
Pterois volitans
• Native to Indo-Pacific
• Found down to 300m
• Eat fishes and crustaceans
• Grow up to 40-45cm
Photo by: John Randall
Reasons for Concern
• Predation impacts
• Few natural predators
• Rapid reproduction
• Unique predation style
Lee Stocking Island,
Bahamas
Exuma Sound,
Bahamas
Perry Institute for
Marine Science
Questions
• What is the feeding rate of lionfish?
• What species do they eat?
• How do their activity levels vary throughout
the day?
• Is their activity affected by other
environmental variables?
Methods
• 10min observations
• 3 sites
• 4 time intervals
–Early morning
–Late morning
–Afternoon
–Evening
•Recorded
-Time of day
- Weather
- Current
- Fish identification
- Activity level
- Strikes and Kills
0
1
2
3
4
Results
• 324 observation periods (10min)
• 104 lionfish
• Strike rate: 19.1 strikes per day
• Kill rate: 9.7 kills per day
Strikes
Kills
n=43
n=22
CARO
STPA 7%
2%
HAGA
2%
THBI
4%
HABI
5%
UNK
42%
THBI
7%
HABI
4%
STPA
5%
UNK
32%
SPAU
9%
SPAU
5%
SCIS
14%
SCIS
9%
COGL: 77% success rate
COGL
21%
SCIS: 75% success rate
COGL
32%
Lionfish Activity by Time of Day
0.5
Activity Level
0.4
0.3
0.2
0.1
0
Early Morning
Late Morning
Afternoon
ANOVA, p-value << 0.001
Evening
Strike Rate by Time of Day
0.50
0.30
0.20
0.10
0.00
Early Morning
Late Morning
Afternoon
Evening
Kill Rate by Time of Day
0.2
0.15
Kills per 10 min
Strikes per 10 min
0.40
0.1
0.05
0
Early Morning
Late Morning
Afternoon
Evening
Lionfish Activity and Current Strength
0.3
Activity Level
0.25
0.2
0.15
0.1
0.05
0
Low
Medium
ANOVA, p-value = 0.0203
High
Lionfish Activity and Cloud Cover
0.6
Activity Level
0.5
0.4
0.3
0.2
0.1
0
Clear
Partly Cloudy
ANOVA, p-value << 0.001
Overcast
Conclusions
• What is the feeding rate of lionfish?
9.7 kills per day
• What species do they eat?
Many, especially bridled gobies & striped parrotfish
• How do their activity levels vary throughout the day?
Active all day, especially dawn and dusk
• Is their activity affected by other environmental
variables?
Yes, activity decreases with current strength and
increases with cloud cover
Special Thanks
HHMI Organization
National Science Foundation
Dr. Kevin Ahern
Dr. Mark Hixon
Mark Albins
Tim Pusack
Gabe Scheer
Tye Kidinger
Meredith Newman
Staff at the Perry Institute
Questions?
PREY PREFERENCE STUDY
Time of Day vs. Average Lionfish
Activity Levels
Average Activity Level
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
4:48
7:12
9:36
12:00
Time
14:24
16:48
19:12
Exuma Sound,
Bahamas
1991-2004 - 0
2005 - 1
2006 - 2
2007 - 107
2008 - 220
2009 - 350
Exuma
Sound
Lee Stocking Island
Regularly visited sites
Data Spreadsheet
Time out
Minimal
Passively Hunting/ Very
Resting (0) Activity (1) Active (2) Hunting (3)
Active (4)
average
17:56
0
0
0
0
1
0.8
11:13
1
0
0
0
0
0
11:38
0.8
0.2
0
0
0
0.04
17:38
0
0.1
0.9
0
0
0.38
14:20
0.9
0.1
0
0
0
0.02
14:29
0.9
0.1
0
0
0
0.02
14:30
0.7
0.3
0
0
0
0.06
14:39
0
1
0
0
0
0.2
14:45
1
0
0
0
0
0
15:01
0.9
0.1
0
0
0
0.02
15:01
0.7
0
0
0.3
0
0.18
Parasite Study
Growth and Survival