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Someone needs to eat these things, say scientists shocked by lionfish surge

July 12, 2013
Courtesy of University of North Carolina 
at Chapel Hill, Oregon State University
and World Science staff

Vo­ra­cious li­on­fish are out-eat­ing sharks, bar­racu­das, and seem­ingly eve­ry oth­er pred­a­tor in the Car­ib­be­an Sea, re­search­ers say.

That’s fu­el­ing renewed con­cern about the spiny lit­tle in­vad­er from the East, which has dec­i­mat­ed na­tive fish in At­lantic coast­al and Car­ib­be­an wa­ters.

Lionfish (courtesy OSU)


Sci­en­tists have a mes­sage for their fel­low hu­mans: eat these guys, please. Oth­er an­i­mals aren’t quite up to the job. 

Li­on­fish are only safe to eat af­ter care­ful re­mov­al of their ven­om­ous, sting­ing spines—which de­ter many pred­a­tors.

Lionfish are quite tasty by ma­ny ac­counts.

Last month, the first ex­pe­di­tion to use a deep-div­ing sub to study At­lantic Ocean li­on­fish found some­thing dis­turb­ing. De­spite ef­forts to con­trol their popula­t­ions, at 100 yards or me­ters deep, there were still size­a­ble popula­t­ions of li­on­fish, and the an­i­mals were big, as long as 16 inches (41 cm), sci­en­tists said.

That raises new con­cerns be­cause big fish in many spe­cies can re­pro­duce far more than lit­tle ones. They nat­u­rally eat more. Li­on­fish are al­so known to trav­el con­si­der­able dis­tances and move to var­i­ous depths.

“It ap­pears that the only way to con­trol them is by fish­ing them,” said John Bru­no, bi­ol­o­gist at the Uni­vers­ity of North Car­o­li­na at Chap­el Hill and lead in­ves­ti­ga­tor of a re­lat­ed study on li­on­fish, pub­lished July 11 in the jour­nal PLoS One.

Para­doxic­ally, it would seem, as hu­mans push many ocean dwellers to­ward ex­tinc­tion through over­fish­ing, harm­ful li­on­fish popula­t­ions are ex­plod­ing be­cause of un­der-fish­ing.

Li­on­fish, na­tive to the In­do-Pa­cif­ic re­gion, have long been pop­u­lar aquar­i­um oc­cu­pants, with their strik­ing stripes and soft, wav­ing fins. They have be­come big ma­rine news as the lat­est in­va­sive spe­cies to threat­en wild­life popula­t­ions. Bru­no likened their ex­tra­or­di­nary suc­cess to that of Bur­mese pythons, now eat­ing their way through Flor­i­da Ev­er­glades fau­na, with few pred­a­tors be­sides alliga­tors and peo­ple.

“A li­on­fish will eat al­most any fish smaller than it is,” said Steph­a­nie Green, a re­search fel­low at Or­e­gon State Uni­vers­ity who par­ti­ci­pated in the di­ves.

The ex­pe­di­tion “was kind of an ‘Ah hah!’ mo­men­t,” she added. “It was im­me­di­ately clear that this is a new fron­tier in the li­on­fish cri­sis, and that some­thing is go­ing to have to be done about it. See­ing it up-close really brought home the na­ture of the prob­lem.”

“When I be­gan div­ing 10 years ago, li­on­fish were a rare and mys­te­ri­ous spe­cies seen deep with­in cor­al crevices in the Pa­cif­ic Ocean,” said Se­re­na Hack­erott, lead au­thor of the PLoS study and mas­ter’s stu­dent in ma­rine sci­ences at the Uni­vers­ity of North Car­o­li­na. “They can now been seen across the Car­ib­be­an, hov­er­ing above the reefs through­out the day and gath­er­ing in groups of up to 10 or more on a sin­gle cor­al head.”

In the pub­lished stu­dy, re­search­ers as­sessed wheth­er na­tive reef pred­a­tors such as sharks and groupers could help con­trol red li­on­fish in the Car­ib­be­an, ei­ther by eat­ing them or out-competing them. Af­ter sur­vey­ing 71 reefs over three years, they con­clud­ed that the an­swer is pret­ty much no.

They did find that li­on­fish popula­t­ions were low­er in pro­tected reefs, at­trib­ut­ing that to tar­geted re­mov­al by reef man­agers, who re­move li­on­fish daily at some pop­u­lar dive sites. “Ac­tive and di­rect man­age­ment, per­haps in the form of sus­tained culling, ap­pears to be es­sen­tial,” the study con­clud­ed.


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Voracious lionfish are out-eating sharks, barracudas, and seemingly every other predator in the Caribbean Sea, researchers say. That’s fueling new concern about the spiny little invader from the East, which has decimated native fish in Atlantic coastal and Caribbean waters. Scientists have a message for their fellow humans: eat these guys, please. Other animals aren’t quite up to the job. Lionfish are tasty and but are only safe to eat after careful removal of their venomous, stinging spines—which deter many predators. Last month, the first expedition to use a deep-diving sub to study Atlantic Ocean lionfish found something disturbing. Despite efforts to control their populations, at 100 yards or meters deep, there were still sizeable populations of lionfish, and the animals were big, as long as 16 inches (41 cm), scientists said. That raises new concerns because big fish in many species can reproduce far more than little ones. They naturally eat more. Lionfish are also known to travel considerable distances and move to various depths. “It appears that the only way to control them is by fishing them,” said John Bruno, biologist at the University of North Carolina at Chapel Hill and lead investigator of a related study on lionfish, published July 11 in the journal PLoS One. Paradoxically, it would seem, as humans push many ocean dwellers toward extinction through overfishing, harmful lionfish populations are exploding because of under-fishing. Lionfish, native to the Indo-Pacific region, have long been popular aquarium occupants, with their striking stripes and soft, waving fins. They have become big marine news as the latest invasive species to threaten wildlife populations. Bruno likened their extraordinary success to that of ball pythons, now eating their way through Florida Everglades fauna, with few predators besides alligators and people. “A lionfish will eat almost any fish smaller than it is,” said Stephanie Green, at research fellow at Oregon State University who participated in the dives. The expedition “was kind of an ‘Ah hah!’ moment,” she added. “It was immediately clear that this is a new frontier in the lionfish crisis, and that something is going to have to be done about it. Seeing it up-close really brought home the nature of the problem.” “When I began diving 10 years ago, lionfish were a rare and mysterious species seen deep within coral crevices in the Pacific Ocean,” said Serena Hackerott, lead author of the PLoS study and master’s student in marine sciences at the University of North Carolina. “They can now been seen across the Caribbean, hovering above the reefs throughout the day and gathering in groups of up to ten or more on a single coral head.” In the published study, researchers assessed whether native reef predators such as sharks and groupers could help control red lionfish in the Caribbean, either by eating them or out-competing them. After surveying 71 reefs over three years, they concluded that the answer is pretty much no. They did find that lionfish populations were lower in protected reefs, attributing that to targeted removal by reef managers, who remove lionfish daily at some popular dive sites. “Active and direct management, perhaps in the form of sustained culling, appears to be essential,” the study concluded.