Short-term impacts of the invasive
Indo-Pacific lionfish on Bahamian
coral-reef fish communities
Research by Megan Cook
Advised by Dr. Mark Hixon
& Mark Albins, OSU Zoology
Pterois volitans
• Native to Indo-Pacific
• Eat fishes & crustaceans
• Found up to 100m deep
• Introduced to SE
Florida in early 1990’s
Establishment
and Spread
Biscayne Bay, FL
Hurricane Andrew, 1992
2000-2007
1990’s
?
?
Hare and Whitfield 2003, Whitfield et al 2007, Snyder and Burgess 2007,
personal communication - Lad Akins, REEF. Map created using Google Earth™
?
Perry Institute for
Marine Science
Lee Stocking
Island, Bahamas
Exuma Sound,
Bahamas
1991-2004 - 0
2005 - 1
2006 - 2
2007 - 107
2008 - 153
(3 weeks)
Exuma
Sound
Lee Stocking Island
Regularly visited sites
Reasons for Concern
• Rapid spread
• Caribbean reefs
degraded, overfished
• Novel predation style
• Few natural predators
• Venomous spines
• Large & abundant
• Marine fish
introductions are
rarely successful
Major Questions of the Invasion
1. What organisms are being eaten?
2. Do lionfish have predators in this new
ecosystem?
3. With which native species (if any) are
lionfish competing?
Major Questions of the Invasion
1. What organisms are being eaten?
2. Do lionfish have predators in this new
ecosystem?
3. With which native species (if any) are
lionfish competing?
Stomach Contents
• Of 52 fish examined…
– 48 with identifiable prey
– 47 with bony fish parts
• 25 ate fish only
– 23 with crustacean parts
• 1 ate crustaceans only
• 11 identifiable species
found from 8 families
• Mixed effects, multifactor ANOVA
– Significant lionfish
effect, p = 0.037
• 79% reduction in net
recruitment by week 5
• 23 of 38 spp.
negatively affected by
lionfish - including 5 of
7 herbivorous spp.
Mean net recruitment (+/- SEM)
Predation Impacts
Control reefs
Lionfish reefs
40
30
20
10
0
1
2
3
4
5
Time post-manipulation (weeks)
Albins, M.A. and M.A. Hixon. (2008). Invasive Indo-Pacific lionfish (Pterois volitans) reduce recruitment of
Atlantic coral-reef fishes. Marine Ecology Progress Series. In Press.
Major Questions of the Invasion
1. What organisms are being eaten?
2. Do lionfish have predators in this new
ecosystem?
3. With which native species (if any) are
lionfish competing?
Predation in Literature
• Predators in native range largely unknown
• One coronetfish in Israel found with 10cm
lionfish ingested1
• Anecdotal evidence of cannibalism
• Only one published account of predation in the
Bahamas: 47.2cm (SL) tiger grouper ate a
6.1cm lionfish2
1.
Bernadsky, G. and D. Goulet. (1991). A Natural Predator of the Lionfish, Pterois miles. Copeia. 1, 230-231.
2.
Maljkovic, A. and T.E. Van Leeuwen. (2008). Predation on the invasive red lionfish, Pterois volitans (Pisces: Scorpaenidae), by native groupers in
the Bahamas. Coral Reefs. 27(3), 501.
Predator Trials
• Captured five local
predatory species (7-46 cm TL)
- 1 Caribbean Octopus (Octopus briareus)
- 2 Nurse Shark (Ginglymostoma cirratum)
- 1 Red Hind (Epinephelus guttatus)
- 3 Nassau Grouper (Epinephelus striatus)
- 3 Graysby (Epinephelus cruentatus)
• Fed once for acclimation,
then offered a 4-10 cm TL
lionfish as potential prey
Predator Trials
• No native predators
ate a lionfish
• Nassau groupers
spent 39 days
without eating their
lionfish
• Red Hind ate a toxic
soapfish but did not
attack lionfish
Major Questions of the Invasion
1. What organisms are being eaten?
2. Do lionfish have predators in this new
ecosystem?
3. With which native species (if any) are
lionfish competing?
Coney grouper
• Common reef predator
• Similar size to lionfish
• Easy to capture
• Rapid predatory strike:
dart from shelter and
immediately return
• Usually found in complex
habitats
Experimental Design
• 21, 6.5 ft3 aquaria with rock habitat at center
• 7 statistical blocks with 3 treatments each:
Coney alone (CX), Lionfish alone (LX), Coney
and Lionfish together (LC)
– Blocks assigned by fish size
• Feeding trials every other day: CX & LX- 2 fish,
LC- 4 fish
• Growth, feeding efficiency, and
_ consumption time recorded
Hypothesis
• If lionfish are adversely affecting coney
grouper, then the growth rate of the native
predator and average consumption per
feeding will be lower in the presence of
lionfish than in the coney-alone treatment.
Results: Growth
• As expected, CX
treatment averaged a
greater growth rate
than CL but not
significantly
• t-test, p=0.935
Average Length Growth Rate
.
• Lionfish grew more
than twice the rate of
coney grouper
Growth Rate (cm/day) +/- SEM
0.03
0.025
0.02
0.015
0.01
0.005
0
Coney Alone
Coney with Lion
Lion Alone
Results: Growth
• Coney grouper grew
poorly regardless of
treatment.
• t-test, p=0.741
.
+/- SEM
Growth Rate (g/day)
•No significant
difference between
growth rate of coney
alone or lion-coney
treatment
Average Weight Growth Rate
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
Coney Alone
Coney with Lion
Lion Alone
Results: Feeding
+/- SEM
Prey consumption
Average Consumption per Feeding
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
• Coneys with lions
ate fewer prey -inhibited by
presence of 2nd
predator
• No significant
difference between
coney feeding
performance
• t-test, p=0.563
Coney Alone
Coney with Lion
• Lionfish averaged
greater consumption
than coneys in all
treatment
A Serious Problem for the Atlantic
• Faster growth rate than native predators
– t-test, p= 0.014
• Higher consumption rate than natives
• Higher resilience: 17 coney deaths in 1 mo
– found live lion with healing spear hole through it
• Complete
eradication unlikely
Average Length Growth Rate
+/-+/(cm/day)
Growth
SEM
GrowthRate
Rate
(cm/day)
SEM
• Population growing
exponentially
0.025
0.02
0.015
0.01
0.005
0
Coney
Lionfish
• Special thanks to:
The HHMI organization, the National
Science Foundation, COS Cripps
Scholarship Fund, Dr. Mark Hixon, Mark
Albins, Darren Johnson, Flower Moye,
Tim Pusack, Dr. Kevin Ahern, Brenda
Gadd and the staff of PIMS
Short-term impacts of the invasive
Indo-Pacific lionfish on Bahamian
coral-reef fish communities
Research by Megan Cook
Advised by Dr. Mark Hixon
& Mark Albins, OSU Zoology