A short compilation of video taken at a Nassau Grouper spawning aggregation on Little Cayman, Cayman Islands. The Reef Environmental Education Foundation (REEF) and the Cayman Islands Department of the Environment are monitoring the recovery of this uniquely large population of endangered fish. The first part of the video shows the aggregation during the day, it then transitions into dusk. Spawning starts about 30 minutes before sunset and continues well past. Toward the end of the clip, a diver is collecting fertilized eggs for genetics work. Visit http://www.reef.org/groupermoonproject for more information.