It took us two days to recover from the from the drubbing we got March 18th at the tidal creek called Lama lagoon. First, we had to completely revamp our catching techniques. Working in daylight would be imperative, and using two unwieldy seines was out of the question. We scared the hell out of the little sharks and they would need several days to rebuild their courage and reestablish their usual pattern of entering the tidal creek on the rising tide But did we have several days???

Tide, time, and the natural rhythms of the lemon sharks were working against us. We made plans to mount our next assault by 06:30 on Saturday morning, the 19th.

At the first light of dawn, our team assembled on deck with high hopes...but Saturday was not starting well. When we inspected our 18' Avon inflatable boat, we found that its engine cowling had become dislodged during the night and had fallen to the bottom of the sea. In a panic, we hoisted the Avon on board and quickly lowered our backup boat, a 13' whaler. The little exercise put us behind schedule by nearly an hour.

By the time we were underway the day was bright and clear with a gentle breeze and the usual ocean swells. Our team, unchallenged this time around by either storms or darkness, set up the tagging station with little discussuon or confusion. Today, we were armed with experience--we were confident--a bit overconfident, it turned out. With very little drama, under clear skies, we quickly set and anchored the seine across the warm flowing waters of the creek. The contrast between that day and the chaos of two nights ago was startling...almost sureal! Our surroundings were a scene of calm, tropical beauty, warm breezes, sparkling seas, and a blue sky filled with oceanic birds. Everybody went about their assigned tasks calmly and quietly. Then our scouts reported back from the upper part of the creek that only nine sharks were milling about. There were none in the mouth of the creek. Only days before there were up to 50!!

Once again we had missed the optimal conditions. We captured our first shark at 08:30 and by 10:00 we were on our way back to the ship, having worked up all nine sharks. We were learning a great deal, though perhaps not the learning that we had originally intended. The main lessons were that the conditions at Atol das Rocas demand daylight work (unlike our Bimini operations which are carried out at night), and that our window of opportunity for Rocas research is tightly controlled by the spring tides and amounts to a mere 5-6 days per month. Finally, we learned that we have only one or two chances to snag the entire population of Rocas's sharks before we "spook" them. After a few bad experiences, they will simply avoid the creek. It just goes to show that you can't fool mother nature-you really have to know your stuff.

As we continued to refine our approach--as our competence and confidence grew over the succeeding days, we managed to mark 40% of Atol das Rocas's estimated shark population and got good recapture rates after only 4 days of fishing. We have gotten our science "down to a science," as they say. Next year, look out! If conditions are right we should be able to mark and collect DNA samples from the entire population in only a few days, then turn our attention to the mating rituals going on in the atoll's main lagoon and to the unique caribbean reef shark nursery outside.

Now we're moving on to Fernando de Noronha, where we'll mount a concentrated effort to strack down and study the more nomadic, adult lemon sharks.