Friday night marked the start of spawning for the Nassau grouper! It was an incredible site to witness. The groupers would shoot upward into the water column as they were spawning, like fireworks.  As the female went up into the water column swimming to release her eggs, several male groupers would follow, swimming in spirals around her. There were several Caribbean reef sharks swimming through the Nassau grouper aggregation site, which was an exciting way to watch the food web in action with the incredible apex predators amongst the groupers.

The day of spawning, the team noticed several things on the morning dive that were clues the spawning might  start later that evening. The female groupers bellies were swollen with eggs, and many more of the fish were in the bi-color or dark phase. There were very few fish in the normal or barred color phase.

The Grouper Moon Team collected some eggs for  a research study being conducted by Janelle Layton and Dr. Scott Heppell from Oregon State University. The research focus is concentrated on the impacts of climate change on Nassau grouper by understanding differences in both morphological traits and gene expression. To collect the eggs, the team used bags to collect samples from various spawning females.

The spawning continued both Saturday and Sunday evenings making for an exciting weekend for both the groupers and the team!

There are many questions about the Nassau grouper that the Grouper Moon Project team have and are researching. This is yet another reason why it’s important to stay curious and always ask questions about the world around you. Do you have any questions for the Grouper Moon Project team? If so, post them as a comment on the blog, and the team will try to answer them for you.