Goliath Grouper Aggregation and Spawning Project

Nineteen volunteer divers from the Florida Oceanographic Society's Palm Beach County Reef Research Team conducted morning and late afternoon dives on Monday, September 15, at several artificial reef locations near the Jupiter inlet to document the aggregation and possible spawning behaviors of Goliath Groupers. Mike Phelan, the Project Coordinator, reported that the dive team documented Goliath Grouper aggregations as large as 50 and recorded many indirect observations of likely spawning behaviors such as coloration changes, pairing of fish on the bottom, and stacking of several fish over another.

The dive team fielded teams of divers that functioned as observers and recorded all aggregation and spawning activities as they actually occurred while other divers photographed the behaviors as further documentation. Surveillance dives were conducted at six known artificial reef sites in waters between 65 and 90 feet deep. The Jupiter Dive Center assisted the team by providing diving and logistic support throughout the day as divers rotated in and out of the water recording on-going events.

The Goliath Grouper is the largest member of the sea bass fish family in the Atlantic. An adult can be 8 feet in length and weigh 300-400 pounds. Its natural range included both the Southwest and Southeast coasts of Florida, Brazil, West Africa, and western Caribbean. With the exception of Florida and a limited area in Brazil, the Goliath Grouper presence has been greatly diminished. The range of the fish has been reduced in modern times by over-fishing or mangrove habitat loss that juveniles use for the first 5-6 years of their 30+ year lifespan.

The Goliath Grouper is an apex predator that does not fear other fish or divers and it can be easily speared for that reason. Phelan reports that it is a magnificent animal to view in the wild and unlike the other reef apex predator, the shark, it is non-threatening and approachable. Phelan reports that the Jupiter area of Palm Beach County is a special eco-system that the Goliath Grouper apparently prefers thereby making Jupiter a world-class diving destination for the diver naturalist. Florida Oceanographic expects to publish its full findings within 30 days.

For further information, contact Mike Phelan, Florida Oceanographic Society Goliath Grouper Project Manager (772) 341-4146.

Visit www.floridaoceanographic.org for additional information about Florida Oceanographic and the Palm Beach County Reef Research Team.