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expeditions/ 2005 RAMP/9_19_05
- Shark Tagging
David Nichols, State of Hawaii, DLNR, HIHWNMS
Chief scientist, Randy Kosaki collects reef fish at
Reef, French Frigate Shoals while accompanied by a white-tip
This was our last day of research activities at French Frigate
Shoals before continuing along the island chain. First on
the agenda this morning was to set a couple of short (10 hooks)
bottom longlines. We were hoping to collect a few sharks in
which to implant the acoustic transmitters. After these were
set we needed to let them “soak” for a few hours
in order to increase the likelihood of hooking a few sharks.
up was a quick dive on “Rapture Reef”. We intended
to collect more fish specimens and the apex predator guys
needed to retrieve the ultrasonic receiver that has been in
the area since May. We have a checklist of reef fish species
that are still needed for further research. The easiest to
collect on this list have already been captured. Now we are
down to those elusive species that require a high degree of
skill (“fish sense”) to capture.
we arrive at Rapture Reef (which was found using the GPS unit
on the vessel) we notice that the floats marking our longlines
were also nearby. Which means we were about to dive in an
area that had scattered chunks of flesh around on hooks with
the sole purpose of attracting sharks. The team starts discussing
(half jokingly – half serious) about proper shark mitigation
procedures for divers in the water.
reef was an amazing dive. It sits in about 80+ feet of water
with such elaborate and healthy table coral that it creates
layers upon layers of potential hiding areas for the heaps
of fish that call this place home. I have never seen such
a huge concentration of aquatic life. By the time I make it
to the reef the white-tip reef sharks are awake and cruising
around. They are a smaller shark and not particularly threatening.
There was also a larger gray reef shark that (according to
the shark guys back on the boat later) appeared to be quite
the rapture reef dive it was necessary to retrieve the longline
and tag any sharks that we happened to catch. Normally this
would require a couple of boats – one to retrieve the
line and another to use as the “implant station”.
However, the weather had picked up considerably and made launching
the second boat a little sketchy, therefore, all the work
was done from the 8-meter HI-2. The first of the longlines
was retrieved with no sharks. I was a little concerned but
shouldn’t have been because we hit paydirt on the second
line including a large (8’) Galapagos shark.
Randy Kosaki, Yannis Papastamatiou, and Carl Meyer
shark alongside the HI-2 to implant an acoustic transmitter.
sharks are brought alongside and tethered to the boat. The
scientists take various measurements and then make a small
incision in the abdomen. The acoustic transmitter is inserted
and the incision is sewn back up. All this work is done with
the shark still in the water alongside the vessel. These guys
make it look easy even in the rough seas. The whole process
takes less than 10 minutes. The longest part of the procedure
(and looks to be the most dangerous) is the hook removal.
Just imagine sticking your hand in a chipper machine. Dr.
Carl Meyer has been doing this for years and as he pulls the
hook out of the large Galapagos, I take a quick count and
he seems to still have all of his fingers attached. Evidently
he has the procedure for removing hooks from large apex predators
pretty well ironed out.
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