Agence France-Presse: Divers plumb the turquoise depths of ocean waters some 100 kilometers south of this vacation paradise, in search of the distinctive queen conch shell prized by vacationers and souvenir-seekers. These divers were not searching for a Mexican holiday keepsake however. They were scientists conducting vital research into the reach of global warming over the centuries in this fragile aquatic ecosystem. The researchers were attaching electronic probes to about 60 specimen of …