What if we are wrong about the lionfish invasion? Craig Layman North Carolina State University
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What if we are wrong about the lionfish invasion?
Craig LaymanNorth Carolina State University
“Lionfish prove to be tireless terminator-like invasive species”
“Godzilla Lionfish Threatening Cayman Paradise”
“In our waters these fishes are consuming everything. They eat everything on a reef.
You have a beautiful little patch reef covered with a rainbow of fish and you come back
after a lionfish has been there for five weeks and 80% of those fish are gone.”
“It’s like an oil spill that keeps reproducing and
will keep reproducing….forever”
One of the top 15 “horizon” global conservation issues for 2010
Introduced by humans to an area where it didn’t occur naturally
Established a breeding population
Populations reach sizes that cause severe environmental harm
Invasive Species
Many exotic species are not invasive
The most destructive invasive species are often predators
Spartina Salt marsh grass European green crab
Asian Clam
The vast majority of coastal invaders are
“low” in the food web (plants or animals that
eat plants)
Lionfish are the most successful invasive
marine predator
How did they get here?
www.joesaquariums.com
Lionfish spread through the western Atlantic and Caribbean: 1985 to 2013
• Numerous introductions
• Reproduce frequently
• Large number of eggs
• Long pelagic larval phase
• Venomous spines (dorsal,anal, and pelvic)
• Naïve predators and prey (enemy release)
• Thrive in degraded habitats
• Generalists
• Rapid growth
Why So Successful?
Research has proliferated almost as fast…as have many debates
Do Prey Recognize Lionfish as a Threat?
Antón et al. MEPS In press
Do Prey Recognize Lionfish as a Threat?
Antón et al. MEPS In press
Jets of Water Directed at Prey
Albins and Lyons 2012 MEPS
Adaptation vs. Exaptation
Introduced by humans to an area where it didn’t occur naturally
Established a breeding population
Populations reach sizes that cause severe environmental harm
Invasive Species
Many exotic species are not invasive
Do lionfish actually alter prey communities?
Albins and Hixon 2008 MEPS
80% reduction in juvenile fish densities
The Seminal Experiment
Layman, et al. 2014 Marine Biology
“At least four caveats are apparent in this study. Most importantly, individual lionfish were confined to a relatively small area, which may have resulted in
disproportionate effects on fauna within cages …. As such, we do not suggest using these data to infer
actual interaction strengths between lionfish and prey.”
Scale of Experiments is Critical
Impacts of invasive lionfish are not apparent on fish community structure on the Mesoamerican Barrier
Reef, Belize (In Press, Ecosphere)
The Invasion Viewed from Ecosystem Scales
So Why Do We Not See Lionfish Effects at Larger Spatial Scales?
*Food web interactions more diffuse at larger spatial scales
*Actual densities may be lower across entire reef tracts
*Recruitment so high, it swamps predator effects
*High connectivity
So what should we do – if anything - about the lionfish invasion?
Coastal Conservation and Management is an Exercise in Prioritization
An important point….. It is definitively an issue of local control rather than eradication
Lionfish at 1000ft detected by the private submarine Nemo
Found in Diverse Habitat TypesCourtesy of Mark Hixon,
Oregon State
Lionfish Reproduction
*15,000 eggs during a single spawning event
*Adult females can lay eggs as many as8 times a month
*Males can be sexually mature at size <4 inches
*Larval fish float in ocean currents for ~30 days
Female Egg Mass
Lionfish Derbies and Similar Efforts Do Contribute to Localized Control
Should it be an International Priority?
*Global microplastic pollution*Incorporating artificial life into natural systems
*Stratospheric aerosols*Genetic techniques to eradicate mosquitoes
*Increases in productivity of polar oceans*Protected area failure*Climate governance
Should it Be a Regional Priority in The Bahamas?
*Bonefish industry valued at $141 million
*Seagrasses cover 65,000km2 – a vast source of blue carbon storage
*Millions of acres of protected areas that need enforcement
*Is mangrove die-off incidence increasing?
*Constant development pressures
So How Has This Emerged as Such a High Profile, Priority, Issue?
*It is “easy” to envision and grasp as an environmental problem
*A charismatic, “sexy”, animal
*Easier for the media to convey to the public than other environmental challenges
*We can see effects of management effects immediately
*Give us a feeling we are making a difference
So What is the Way Forward with Respect to the Lionfish Invasion?
*A move away from lionfish-centric studies
*Incorporating lionfish into general ecological theory
*Better incorporate cost-benefit considerations into allocating time and money to lionfish research
*Remembering the difference between factual and judgment statements with respect to invasive species
Introduced by humans to an area where it didn’t occur naturally
Established a breeding population
Populations reach sizes that cause severe environmental harm
Invasive Species
Many exotic species are not invasive
In Defense of the InvadersMost campaigns against foreign plants and animals
are pointless, and some are worse than thatThe Economist – December 5, 2015
More on lionfish over at Abaco Scientist……
https://appliedecology.cals.ncsu.edu/absci/
What if we are wrong about the lionfish invasion?
Questions and discussion…
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