‘Roaches of the sea’ now are men­ac­ing the Gulf

San Antonio Express-News (Sunday) - - Front Page - By Alex Stuckey STAFF WRITER

Sci­en­tists bat­tling co­ral reef deaths caused by warm­ing ocean wa­ters 100 miles off the coast of Galve­ston might have an­other cli­mate-change prob­lem to fight in com­ing decades: a pro­lif­er­a­tion of ze­bras­triped lion­fish.

Lion­fish — brought to the U.S. from their Indo-Pa­cific home to stock aquar­i­ums and later dumped by own­ers un­able to care for the con­stantly hun­gry ver­te­brate — have no known North Amer­i­can preda­tors to stop their spread.

As a re­sult, they’ve been dec­i­mat­ing reef pop­u­la­tions from New York to Florida since the 1980s, ar­riv­ing at the Gulf of Mex­ico’s Flower Gar­den Banks Na­tional Marine Sanc­tu­ary in 2011.

A re­cent study pub­lished in the Wilder­ness & En­vi­ron­men­tal Medicine jour­nal sug­gests ven­omous crea­tures like lion­fish will be­come more preva­lent as the oceans warm.

“They are the cock­roaches of the sea,” said Michelle John­ston, a sanc­tu­ary re­search bi­ol­o­gist. “They re­pro­duce ev­ery four days and ev­ery four days they can re­lease up to 50,000 eggs. Plus, noth­ing re­ally eats them, they have ven­omous spines and the na­tive fish are ter­ri­fied of them.”

Lion­fish thrive in warmer tem­per­a­tures, which is why sight­ings are more com­mon in south­ern ar­eas such as Florida. But as ocean tem­per­a­tures con­tinue to warm, sci­en­tists

be­lieve their pop­u­la­tion ar­eas will con­tinue to grow.

“Many as­pects of lion­fish life his­tory and be­hav­ior are ex­pected to be tem­per­a­ture-de­pen­dent,” the study states. “With­out culling ef­forts, the spa­tial ex­tent of suit­able year-round lion­fish habi­tat is ex­pected to in­crease 45 per­cent on the South­east United States con­ti­nen­tal shelf dur­ing the 21st cen­tury, cov­er­ing 90 per­cent of the re­gion.”

This would cause prob­lems all the way up the food chain and af­fects not only the health of the reef but also the liveli­hood of the fish­er­men who de­pend on it, John­ston said.

Sanc­tu­ary of­fi­cials at Flower Gar­den Banks are do­ing what they can to curb the lion­fish in­va­sion, con­duct­ing a num­ber of re­con­nais­sance mis­sions to re­move as many of these in­va­sive fish as pos­si­ble from the 56-square mile, fed­er­ally pro­tected sanc­tu­ary.

De­spite their ef­forts, the fish now num­ber in the thou­sands — and sci­en­tists be­lieve that count is low.

If they want to make a real im­pact, John­ston said, they’ll need to come up with bet­ter so­lu­tions — and fast.

“Ul­ti­mately, it’s our fault and we have to deal with these con­se­quences,” John­ston said.

Un­wel­come guests

At one time, lion­fish only could be found in the warm, trop­i­cal wa­ters of the Indo-Pa­cific, their red­dish-brown and white stripes eas­ily rec­og­niz­able on reefs dot­ting the coast­lines of Aus­tralia, Malaysia, Ja­pan and French Poly­ne­sia.

Recre­ational divers de­lighted at spot­ting the un­usual fish in the briny wa­ter, but their al­lure led to some­thing much more prob­lem­atic: peo­ple started stock­ing home aquar­i­ums with them, es­pe­cially in the United States.

Lion­fish are great con­ver­sa­tion starters be­hind an aquar­ium’s glass walls, but they’re in­dis­crim­i­nate preda­tors and will quickly dec­i­mate a fish pop­u­la­tion.

They can eat up to 30 times their stom­ach vol­ume and have a wide-rang­ing diet that in­cludes more than 70 dif­fer­ent species of fish, as well as in­ver­te­brates like shrimp and crab, ac­cord­ing to the Ocean Sup­port Foun­da­tion, a Ber­muda-based or­ga­ni­za­tion founded in 2011 to man­age the lion­fish in­va­sion.

“If you put a lion­fish in a salt wa­ter aquar­ium — well, they like to eat,” John­ston said. “The lion­fish start eat­ing all the fish in the aquar­ium, and peo­ple, in­stead of giv­ing it back to the pet store, they just dump the fish.”

The first signs of this came in 1985, when a lion­fish was spot­ted off the coast of south­ern Florida, ac­cord­ing to the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion.

By 2000, the numbers in­creased dra­mat­i­cally as lion­fish found each other and mated.

It’s a prob­lem be­cause lion­fish are such pro­lific re­pro­duc­ers. A sin­gle lion­fish can pro­duce up to 6 mil­lion eggs each year, ac­cord­ing to NOAA, and live up to 30 years.

They made their way to the coasts of Alabama, Louisiana and Mis­sis­sippi by 2010 and, a year later, the ven­omous fish ar­rived at Stet­son Bank, one of the three co­ral reef sys­tems that make up the fed­er­ally pro­tected sanc­tu­ary in the Gulf of Mex­ico, ac­cord­ing to the sanc­tu­ary.

Be­tween 2011 and 2017, re­searchers have recorded nearly 3,500 lion­fish in the sanc­tu­ary, NOAA stated, though ex­perts be­lieve that num­ber is low.

And just as the lion­fish did in house­hold aquar­i­ums, they started eat­ing ev­ery­thing in sight.

A sin­gle lion­fish can eat up to 5,000 fish per year, John­ston said.

In the Indo-Pa­cific, lion­fish preda­tors in­clude sharks, grouper, frog­fish, large eels and scor­pi­onfish, ac­cord­ing to Lion­fish Hunters, a group that pro­motes the re­moval of lion­fish from the Western At­lantic Ocean, Caribbean Sea and Gulf.

But fish na­tive to the Flower Gar­den Banks don’t know lion­fish are preda­tors, John­ston said, which makes the ven­omous fish’s food gath­er­ing that much eas­ier.

“The lion­fish are vir­tu­ally unchecked” in Flower Gar­dens, John­ston said. “The ones we’ve col­lected are ex­tremely large, they’re obese, and some of them have fatty liver dis­ease. They’re eat­ing them­selves into obliv­ion.”

Fish­ing con­cerns

John­ston be­lieves the study’s pre­dic­tions about a mass lion­fish takeover is slightly alarmist, but she said it makes good points.

The only thing that lim­its a lion­fish’s range is cold tem­per­a­tures, she added, and if wa­ters were warmer they’d likely spread out more, po­ten­tially trav­el­ing even deeper into the ocean.

“As far as cli­mate change, if it’s go­ing to get warmer, then yes their range could po­ten­tially broaden from where it is now, maybe go­ing farther up the East Coast,” she said. “Lion­fish do not like the cold.”

Lion­fish have shown a pref­er­ence to wa­ter tem­per­a­tures around 73 de­grees Fahren­heit, ac­cord­ing to the peer-re­viewed news­let­ter, Bio­di­ver­sity Sci­ence.

If the study’s pre­dic­tions are ac­cu­rate, the lion­fish would put an even big­ger strain on the com­mer­cial fish­ing in­dus­try.

In Florida, for ex­am­ple, lion­fish have been known to feed on snap­per and grouper — ma­jor eco­nomic driv­ers in the state.

“The di­ver­sity of fish in Florida is be­ing sig­nif­i­cantly al­tered by the lion­fish, putting a strong eco­nomic en­gine at risk,” ac­cord­ing to the Taxwatch Cen­ter for Com­pet­i­tive Florida in 2015. “One of the top species har­vested in Florida is the red grouper (with a 2010-11 dock­side value har­vest of $15.1 mil­lion), which com­petes with the lion­fish for prey, and is of­ten prey it­self.”

And the true threat of this in­va­sive species still is be­ing sorted out.

In an­other study pub­lished last year, Matthew John­ston, a re­search sci­en­tist at Florida-based Nova South­east­ern Univer­sity, found not much is known about the true eco­nomic im­pact. Data are needed quickly, he said, to help mit­i­gate dam­age.

“We’re talk­ing mil­lions of dol­lars in the fish­ing in­dus­tries — from catch­ing and sell­ing var­i­ous fish to the hun­dreds of thou­sands of jobs and the recre­ational as­pects of fish­ing,” he said. “If left unchecked, there is the real po­ten­tial that lion­fish will have a neg­a­tive im­pact on the fish­ing in­dus­try. It’s likely that they are neg­a­tively im­pact­ing pop­u­la­tions of the fish we like to eat, and at an alarm­ing rate.”

Luck­ily those neg­a­tive im­pacts haven’t reached Flower Gar­den Banks yet, said Buddy Guin­don, a com­mer­cial fish­er­man who owns Katie’s Seafood Mar­ket in Galve­ston.

“We haven’t seen any no­tice­able changes, but there’s an abun­dance of lion­fish on Flower Gar­den Banks,” Guin­don said. “We’re think­ing that the big snap­per and grouper have started eat­ing them.”

No real so­lu­tions — yet

This late into the lion­fish in­va­sion, there’s no real way to com­pletely erad­i­cate the species from the en­vi­ron­ment it never was meant to in­habit, Michelle John­ston said.

But sci­en­tists cer­tainly are try­ing to mit­i­gate the dam­age.

In the Flower Gar­den Banks specif­i­cally, sanctu- ary of­fi­cials have con­ducted four sep­a­rate vol­un­teer dives to hunt the fish, pulling 1,200 from the reef sys­tem this past sum­mer with pole-spears, John­ston added. But they know that isn’t enough.

“Re­mov­ing lion­fish through div­ing ef­forts is not the solution to the prob­lem,” she said. But “it is def­i­nitely a tool to help mit­i­gate the lion­fish in­va­sion and to help keep it from get­ting worse.”

At NOAA, sci­en­tists are de­vel­op­ing spe­cial, clamshell-shaped traps to catch lion­fish on the ocean floor.

Com­pa­nies also are get­ting into the fray.

Vir­ginia-based R3 Dig­i­tal Sciences is build­ing a trap com­plete with a small cam­era that al­lows the de­vice to iden­tify lion­fish.

Only lion­fish would be al­lowed to en­ter the trap, ac­cord­ing to a May 2018 ar­ti­cle pub­lished in Ocean Deeply, a dig­i­tal me­dia pro­ject that fo­cuses on ocean health.

And in Mas­sachusetts, Worces­ter Poly­tech­nic In­sti­tute stu­dents are tak­ing it one step fur­ther, build­ing an un­der­wa­ter ro­bot to hunt lion­fish.

“The goal is to be able to toss the ro­bot over the side of a boat and have it go down to the reef, plot out a course, and be­gin its search,” Craig Put­nam, as­so­ciate di­rec­tor of the in­sti­tute’s Robotics Engi­neer­ing Pro­gram, said in an Au­gust state­ment. “It needs to set up a search pat­tern and fly along the reef, and not run into it, while look­ing for the lion­fish. The idea is that the ro­bots could be part of the en­vi­ron­men­tal solution.”

John­ston isn’t sure what the an­swer is for Flower Gar­den Banks, es­pe­cially since the reef sys­tem is so deep. But tech­ni­cal divers, who can swim much deeper than recre­ational divers, will come to the sanc­tu­ary next sum­mer to learn more about lion­fish be­hav­ior in the depths of the Gulf.

For now, all sanc­tu­ary of­fi­cials can do is man­age the area by hunt­ing the lion­fish and re­mov­ing as many as they can.

“It’s a process that’s never-end­ing. We re­move them from the shal­low ar­eas and they come up from the depths. But that’s not a true solution,” she said. “The solution is for the sys­tem to nat­u­rally sort it­self out.”

“Ul­ti­mately, it’s our fault and we have to deal with these con­se­quences.”

Michelle John­ston, bi­ol­o­gist

Ralph Win­ing­ham / Con­trib­u­tor

A sign on Bob Hall Pier on North Padre Is­land ad­vises an­glers on how to safely han­dle and clean the ven­omous Lion­fish.

David J. Phillip / Associated Press

A lion­fish swims near co­ral off the Caribbean is­land of Bon­aire.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.