We had an adventurous welcome to the atoll as this wave broke over our skiff, leaving us soaked and half-flooded.
Testing the net that will be used to corral the lemon sharks, four researchers work in the excessively warm shallows Atol das
Rocas's interior lagoon.
Retreaving the massive CTD requires the use of the ship's
onboard crane with crew members to guide the device back onto deck.
Killed by a suspected shark bite, a bone fish provides a welcome
clue that more sharks may be in the area.
Atol das Rocas teems with bird life. Having little contact
with people, the island's masked booby population seems unafraid of humans.
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DISPATCH 04: The First Shark Arrives!
@Sea correspondent/photographer, Mark Carroll
Team members begin their search for sharks after landing at Atol das Rocas for the first time.
8:09am, ship's conference room -- The daily crew meeting seemed to drag a bit
this morning. Beyond hassling with the logistics of fitting 29 scientific
crew into three small boats going eight different ways, there was a language
barrier to contend with. Every discussion had to be translated into
Portuguese for the Brazilian team members and visa versa for those of us
whose best attempt at Portuguese consisted of loud, slow English and exaggerated hand
Our sluggish morning did not foretell the successes to come.
After the meeting, several teams set off to Atol das Rocas. The first team planned
to mark the narrow, difficult channel leading to the lagoon. Without access
to the center of the atoll, the mission can not succeed. This interior lagoon represents a
key habitat for the lemon shark, a creature adapted to living in waters with low oxygen levels with wildly fluctuating temperatures.
Team 1 succeeded in clearing the channel, and the second team followed, sweeping the area, looking for
sharks. Within the hour, they met with success -- the first shark of the
expedition! Heading through the newly marked channel, a lemon shark, 4 to 5
feet in length, swam under the boat. Encouraged, snorkelers entered the
water inside the lagoon and met with two more animals, nurse sharks this
time -- not the species of choice, but a heartening discovery, regardless.
10:52am, 15 miles off Atol das Rocas -- Gruber approaches his shark studies
from a grand, oceanic perspective. Without providing the broadest possible understanding of these sharks' environment, it is meaningless simply to provide isolated data on how they mate, live, and die. The oceanographic capabilities of the Research Vessel SEWARD JOHNSON (RVSJ) were put to work uncovering this background information, or bringing it to the surface, as the case may be.
As the landing parties surveyed the island, the rest of the crew
headed back out to sea aboard the RVSJ. A device known as a CTD (an acronym for Conductivity, Temperature, Depth) was lowered 300 feet into the sea, capturing data on the water's chemistry and retreiving plankton samples. This information will help to establish a truly comprehensive view of the lemon shark's world.
2:25pm, onshore at Atol das Rocas -- Expedition member Guilherme Barbosa has
previously studied lemon sharks at Atol das Rocas. His research suggests
that the arrival of sharks at the atoll is closely tied to the rhythm of the
tides. Barbosa's data predicts a large influx of
sharks within the coming week, with the first arrivals expected tomorrow.
Armed with this knowledge, a new group of scientists landed on the atoll's
beach, then made their way, on foot through the sandy and muddy shallows of
the lagoon with the brutal equatorial sun overhead. Although the party
found no young sharks, they did uncover evidence of shark feeding -- a bone
fish torn in half with a tell-tale crescent bite mark.
From the shore, the atoll only vaguely resembles its appearance from sea.
Behind the steep, white sand beach and the island's five trees, a warm lagoon
provides protection for animals. Most of the meandering shores are covered in an unfamiliar, flowering grass that
harbors thousands and thousands of birds: the magnificent frigatebird, the
masked booby, the sooty tern and the brown noddy -- all virtually oblivious
to the presence of humans.
Navigating the atoll's treacherous channel, with its swift current and large waves,
is a daunting way to get past the breakers. A miss-timed run or an unexpected swell could easily flip the expedition's small skiffs. Just short of calmer waters, a wave crashed into
my team's equipment-laden boat, leaving us soaked and half-flooded.
11:52pm, onboard the SEWARD JOHNSON -- No sleep for science. Within earshot, a small group of researchers, excited by today's success, plans tomorrow's day in the
field. In a few short hours we will head back to the atoll, hopefully to meet the first arrivals of the expected influx of sharks.