The menacing storm that put a premature end to the day's research never hit as hard as expected. Ironically, the longlining night team, trapped in the lagoon until morning, was pelted all night by another unpredictable storm.

12:26pm,March 17, outside Atol das Rocas lagoon -- Engine troubles continue to plague the expedition. Two of the three smaller boats now have erratically functioning motors, so getting to the lemon shark observation sites is an adventure in itself. Sputtering engines notwithstanding, the search for the lemon sharks continues.

1:00pm, Atol das Rocas lagoon -- High tide deepened the passage leading to the atoll's interior lagoon, allowing all three of the boats to enter without incident. As the teams swept the lagoon in erratic search patterns, looking for fins, scanning for silhouettes of lemon sharks, it became obvious that the deeper waters of high tide were hindering the visual search. Rocks and turtles became sharks, distorted by the additional six feet of water surging into the sheltered cove. Although several lemons were spotted, nurse shark sightings continued to dominate the action.

On the other side of the island in a small, sheltered inlet, the baby lemon sharks continued to gather. A modest landing party monitored the sharks, counting just over 60 animals schooling within the inlet. In the coming days, these juveniles will provide a rich bounty of genetic data for the researchers. In the mean time, the expedition waits for the shark numbers to reach their peak.

4:23pm, Atol das Rocas lagoon -- Sharks are difficult to control, but they can be hooked and subdued. The weather, however, cannot. While most researchers focused their attentions into the ever-deepening water, the sky darkened. When the clouds were no longer easy to ignore, the boats converged in the center of the lagoon, tied together like a refugee flotilla and discussed options. Although a unanimous decision was not reached, the day's search mission was ultimately cut short, and the crew returned to the ship.

6:09pm, R/V SEWARD JOHNSON -- The menacing storm that put a premature end to the day's search never hit as hard as expected. So, the night longlining night team readied their boats and headed to the lagoon for an all-night excursion.

Sharks are more active at night. The longliners hoped to capitalize on this behavior and capture some large lemons for tagging and genetic sampling. Once in the lagoon, they were committed to a full night, trapped by the receding tide, physically cut off from the rest of the expedition until morning. This was field science in the grittiest sense.

12:13am, March 18, onboard the Research Vessel SEWARD JOHNSON (RVSJ) -- I listened in on a radio conversation between researcher Dan Cartamil onboard the RVSJ and scientist Dean Grubbs, who had just finished checking the longline for sharks. They had successfully captured, sampled, tagged, and measured a large lemon shark. The success of the entire mission depends on this kind of vital information.

1:30am, onboard the RVSJ -- Another unexpected storm currently pounds the night team in their small, open-air skiff. Most people onboard the SEWARD JOHNSON have gone to their dry beds, resting for tomorrow -- another day at sea, as unpredictable as today's weather.