Page 28 - ARUBA TODAY

A28 SCIENCE
Wednesday 5 February 2020
Open sores, lower numbers likely not invasive lionfish's end

NEW ORLEANS (AP) — A fish had wounds. I dismissed
new disease has caused it," Fogg recounted. But ev-
open sores that can eat ery dive that day brought
into the muscles of inva- up fish with lesions. Out of
sive lionfish and appears 503 lionfish, 201 had ulcers.
to have contributed to an Ulcerated fish have since
abrupt drop in their num- been reported around
bers in the northern Gulf of Florida and throughout the
Mexico, scientists reported Caribbean. The University
Tuesday. But they hasten of Florida put a first report
to say it's probably far from about the ulcers online in
the end of the showy in- September 2018.
vader with long, venomous "We're still trying to figure
spines. out what's going on," said
Lionfish may even already Roy P.E. Yanong, of the
be bouncing back, said Tropical Aquaculture Lab-
University of Florida doc- oratory at the university's
toral student Holden Harris, program in fisheries and
lead author of the article aquatic sciences. Tests for
published online in Scien- molds, bacteria and viruses
tific Reports. Numbers of didn't indicate a likely cul-
the smallest lionfish taken prit, he said.
by spearfishers were way One problem, he said, is
down in 2018, indicating that the sores were open to
a possible reduction in microorganisms in the wa-
spawning, but were rising ter and en route to a lab.
late that year and in early Finding fish in a very early
2019, he said. stage of the process would
"It's too early, really, to say if probably help, but that it-
that'll become a full popu- self has been a problem,
lation recovery," he said. he said.
It's an interesting develop- Environmental factors
ment, said Matthew John- This photo shows a lionfish in the Audubon Aquarium of the Americans at New Orleans on Sept. could also be a major
ston, a Nova Southeastern 23, 2018. cause, Yanong said. Other
University researcher who Associated Press possible causes could in-
has written scientific pa- clude physical trauma and
pers about invasive lionfish of water to make small en by remotely operated ecology at the University of parasite infection, National
but had not known about plankton-eaters face them, underwater vehicles in a Florida. Commercial land- Oceanic and Atmospheric
the lesions or population then vacuum them in. They 20,000-square-kilometer ings fell 52% from 2017 to Administration spokeswom-
changes. "We've always have few natural predators (7,700-square-mile) area of 2018. And, though lionfish an Allison Garrett said.
been wondering if they're in the area, where they eat the Gulf of Mexico that has tournament catches rose "It could be a combina-
ever going to reach their native fish and compete been regularly surveyed for each year, spearfishers tion," said Johnston of Nova
limit in certain locations," with them for food. a wide variety of species had to hunt more reefs to Southeastern. "They're
he said. "To date it seemed "They've pretty much col- since the BP oil spill in 2010. find them. overcrowded, they're
the populations just kept onized the entire Carib- They looked at the weight Patterson said scientists competing for food ... and
getting larger and larger bean and Gulf of Mexico of lionfish landed in com- haven't yet analyzed un- the gene pool's really shal-
and larger." and up the East Coast of mercial fishing trips and at derwater videos from 2019. low." He said genetic stud-
One reason lionfish are a the U.S. up to about Cape numbers of fish taken per Many invasive species ies have shown the invad-
problem outside their na- Hatteras. But it's just about reef in lionfishing contests. have gone through boom- ers are descended from
tive Indo-Pacific is that impossible to estimate how And by all of those mea- and-bust cycles, he noted. a small number of lionfish.
their hunting method was many there are," Johnston sures, numbers fell in 2017 One of the spearfishers "So if one gets sick they're
new to their adopted ter- said. "They're found very and 2018. "The magnitudes who first brought the lesions all susceptible to the same
ritory, so their prey hadn't deep and in lots of places of the declines were strik- to light said lionfish num- thing."
evolved countermea- we can't look easily." ing," Harris said. bers on his hunting grounds Lionfish were first sighted
sures. The big-mouthed Researchers measured the The densities shown in un- have stayed low although off Florida in 1985; aquar-
fish hover over smaller fish, Gulf of Mexico changes in derwater vehicle footage the sores seem "pretty ium hobbyists may well
then suddenly gulp them a number of ways besides dropped about 75 per- much nonexistent now." have started the inva-
down, swallowing prey up the proportion of little lion- cent, said coauthor William Alexander Q. Fogg, a study sion by dumping fish into
to half their own length. fish in spearfishers' totals. F. Patterson III, an associate coauthor and marine re- the ocean, according to
Sometimes they blow jets They analyzed videos tak- professor of marine fisheries sources coordinator for the NOAA.
Okaloosa County, Florida, University of Florida's Harris
Board of County Commis- said researchers had two
sioners, regularly catches big worries when reporting
lionfish to help control their about the sores: that peo-
numbers and to sell as food. ple might think lionfish were
He said his diving partner, unsafe to eat, and that
Josh Livingston of Dread- they might think that nature
knot Charters, first noticed had ended the invasion.
sick or injured lionfish off "The densities have gone
artificial reefs near Destin, down in some places. We
Florida on Aug. 5, 2017. don't know if they'll stay
"He said he noticed a lot of down," he said. q