After posting a lifetime best in the morning qualifying sessionn of the 200-meter freestyle, Tampa’s Chelsea Nauta saw her Olympic hopes end in the event when she finished 16th in the semifinals Tuesday night at the U.S. trials in Omaha, Neb.

Nauta, a Tampa Prep product now competing for the University of Georgia, swam 2 minutes, 0.17 seconds in the semifinals at the Qwest Center. The eight qualifiers for the finals all broke 1:59, including No. 1 seed and American record holder Katie Hoff, who went 1:57:10. Hoff’s American record is 1:56.08.

If she had made the finals, Nauta had a good shot at making the Olympic squad in the 4x200 free relay. Typically, the top six finishers in the finals of the trials’ 200 free are selected for that relay pool. The top two finishers in the finals earn the individual Olympic berths in the event.

Also in the women’s 200 free first-round qualifying, 17-year-old Megan Romano of St. Petersburg Northeast High, finished 46th overall and sixth in her heat at 2:01.91. That’s about a second off her PR (2:00.98) but Romano came into the meet still suffering the lingering effects of mononucleosis.

In Tuesday’s other qualifying event, the 200 individual medley, Clearwater Countryside’s Melanie Margalis, the younger sister of national team swimmer Robert Margalis, had the 69th-fastest time at 2:20.02.