Groupers, and a wide variety of other reef fish such as snappers, triggerfish and grunts, migrate long distances from their home sites to certain locations for spawning events which take place in large groups, or aggregations.

The Grammanik Bank, located just south of St. Thomas, is also the only known spawning location in the region for critically endangered Nassau grouper. The Nassau grouper spawning aggregation at the Grammanik Bank is a very special place. The US Virgin Islands are very fortunate because this is the only location in the entire Caribbean where Nassau grouper have shown signs of recovering

In the US Virgin Islands, large species parrotfish have been removed from the ecosystem and indeed the marine food chain. The consequence of this loss is unknown.

With vigilance, education and regulations, Nassau grouper stocks may once again be plentiful.