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plastic with serial numbers and contact information) using the underwater
protocol described in the article. The tagging procedure took approximately
three minutes per fish, and the tagged fish were released back to their
original capture locations within minutes. The lionfish handled the tagging
procedure extremely well; no post-tagging mortality or unusual behavior was
documented in any of the fish.
Opportunistic sightings of lionfish by divers visiting the tagging area and
nearby reefs provided an indication of the success of the tagging work. Of
the 161 lionfish tagged, 24 percent were resighted or recovered between 29
and 188 days after tagging. Of those, 90 percent were found at the same site
where they were initially tagged. Of the fish that were documented to have
moved, movement was primarily between patch reef sites in shallow water.
While 24 percent is an extremely high return rate for a mark-and-
recapture study, one may wonder what happened to the other 76 percent
of the tagged lionfish. Some may have died or been eaten, some may have
moved far beyond the survey area, and others may have migrated deep down
the wall beyond recreational diving limits. For the fish tagged in this initial
study, we’ll never know.
To help mitigate this uncertainty, some researchers are now using surgically
implanted acoustic transmitting tags and remotely deployed receivers that
monitor lionfish positions 24 hours a day. The surgical procedures used in
the acoustic tagging closely follow the visual tagging method and are proving
to be very successful in initial trials. The primary differences between the two
tagging methods are that the surgical procedure requires suturing the tagged
fish following insertion of the tag, which is about the size of an AAA battery,
and also involves a slightly longer procedure time — approximately five to
six minutes per fish. A more detailed study using an acoustic receiving array
is planned for this summer and will provide continual movement data to a
resolution of approximately 1 meter.
In science as in life, the more we learn, the more questions we have. As
the lionfish invasion progresses, the need for information about new tools
and technologies for management and removal continues to increase.
Combining the efforts of divers with the knowledge gained through research
projects enhances our ability to combat the invasion more effectively and
protect our native marine life from a fish that doesn’t belong in this part of
the world. AD
22 | SPRING 2016
DIVE SLATE
LIONFISH
LIONFISH QUICK FACTS
Distribution: North Carolina to Venezuela;
shallows to 1,000 feet deep
Density: more than 200 per acre (up to
1,200 per acre in some locations)
Reproduction: 12,000 to 40,000 eggs
as often as every two days, year round in
warmer waters
Maximum Size: 18.77 inches (official
measurement); 20.47 inches (unofficial
measurement)
Age of 18.77-inch specimen: 4 years,
9 months
Maximum age: up to 15 years (One
specimen in an aquarium lived for 30 years.)
Genetic makeup: only 9 haplotypes in the
entire invaded territory
Removal success: Two divers removed
815 lionfish in a single-day derby event in
Jacksonville, Fla., in 2015. Derbies have
been shown to reduce lionfish populations
by about 70 percent across 58 square
miles in the Bahamas.
For more information, visit
lionfish or
DIVING AS IT SHOULD BE!
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Turks & Caicos Islands have to offer.
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