What if we are wrong about the lionfish invasion?€¦ · Cayman Paradise ” “In our waters ......

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…