Overview:Originally, in 2014, Laurent Ballesta had just one precise objective: to unravel the mystery of groupers. To understand the issues involved in their collective reproduction. But although focused on the study of groupers, the real surprise came from the sharks. Never before had the team been confronted with such a density of grey reef sharks. The divers took up the challenge of counting them. Methodically, they repeated the operation many times to arrive at the impressive figure of 700 grey reef sharks. Each year, the team returned to the southern pass of Fakarava in French Polynesia. Until 2019, for the fourth expedition, "Gombessa 4" is the synthesis of precise and unique scientific protocols. The mission demonstrated that shark hunts are not anarchic, but rely in part on social organization within the horde, following in the footsteps of the 700 grey sharks in "700 sharks in the night (Gombessa 4, Genesis)".