7:05am, March 19, onboard the Research Vessel SEWARD JOHNSON (RVSJ) -- Yesterday's landing party returned with their injured team member, Dan Cartamil, recovering from a nasty shark bite. I asked him for the story before the shark grew larger than a meter.

"I was tired and cold," said Cartamil. "I had been sitting in the water for three hours. I grabbed the shark with one hand and was reaching with the other when it flashed its head to the side and bit me. It was so fast! I didn't even think he got me at first, but then the blood started."

Cartamil and the rest of the team eagerly retired to their quarters, exhausted from a wild night of tagging, sampling, and limited sleep on the atoll's beach (which has a healthy population of scorpions and cockroaches).

2:10pm, in the waters off Atol das Rocas -- With most of the ship still recovering, I set off with several other team members to explore the underwater sights of this surreal place. The water close to the atoll was alive with tropical fishes: angelfish, parrotfish, wrasses, chubs. Of course, the nurse shark made its regular appearance, as did several swift Caribbean reef sharks. When someone yells "shark!" around here, everyone actually jumps INTO the water -- crazy scientists!

1:00 am, main deck of the RVSJ -- Other than those on watch, the R/V SEWARD JOHNSON is a ghost ship this time of night, rocking and droning. Not a bad place to fall asleep once you get used to it.

While releasing an extremely flexible, young lemon shark, researcher Dean Grubbs gets bitten on his upper thigh. Luckily, a wetsuit provided protection against any injury.

5:45am, March 20, main deck of the RVSJ -- Up before dawn, the team prepared for an island landing as the sun rose over nearby Atol das Rocas. For some, this would be the first solid ground their feet had touched in quite a while. But, with the wet and wild shark round-up at hand, there would be little time to enjoy the atoll's terra firma.

7:00am, the beach at Atol das Rocas -- Immediately upon reaching the beach, eleven scientists moved into action. We arrived only slightly behind schedule after affecting a minor field repair on one of the skiffs. I heard someone scream from the other boat, "Without duct tape, there would be no science!"

The operation required us to arrive at high tide, when baby sharks gather in the atoll's interior lagoon. Then, it would just be a matter of dragging a net across the lagoon's inlet and waiting for the tide to recede.

Within minutes of our arrival, the nets were in place and the tide was falling. Right away, a few sharks darted into the net. Each captured animal was hand-carried to the field lab (consisting of a few saw horses, some plywood and assorted instruments), then measured, sexed, weighed, genetically sampled, and fit with a transmitter tag.

Ten more sharks arrived, nearly all at once. With the tide falling rapidly, the young animals were looking for a way out. The beach erupted into action: sharks, scientists, shark-handlers, data recorders, net operators. It was a fast-moving ballet. It had to be. Time was the enemy.

Sharks, (especially young, stressed sharks), have little time to live once pulled from the water. No one wanted a shark to die, especially Dr. Gruber. So much effort had gone into securing permits to pursue research in this tightly guarded marine sanctuary. If the team accidently killed a shark, the mission would be over. No questions asked.

So, the pressure was on and the scientists rose to the challenge. The sharks were back in the water and free within three minutes, tops, with nothing to show for their troubles but a tag and a temporarily-notched fin. Within a week, these small notches -- momentos of having been genetically sampled -- will heal.

4:00pm, onboard the SEWARD JOHNSON -- For the next fifteen hours, I'll be at sea in a small skiff with a team of four researchers. We'll be longlining for adult lemon sharks throughout the night while the big animals are most active.