A new article published by researchers with the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute helps shed new light on goliath grouper in the Gulf of Mexico. The paper titled, "Behavior, Habitat, and Abundance of the Goliath Grouper, Epinephelus itajara, in the Central Eastern Gulf of Mexico" describes the results of joint research effort between divers and scientists to explore goliath grouper distribution and abundance along the central west coast of Florida between October 2007 and May 2010. The project's aim was to address how goliath grouper presence, abundance and size distribution are related to habitat, depth and season.
Below are some of the highlights from the project:
- Goliath grouper were observed during all months of the year and were present during 74% of all surveys (280/378).
- Presence and abundance were significantly related to habitat type and depth, with highest presence and abundance recorded over deep, artificial reefs.
- The maximum number of goliath grouper observed during a single survey ranged from 0 to 24.
- The mean number observed per site over artificial reefs was 4.53 versus 0.45 over natural habitat.
- The number of fish observed over artificial habitats tended to increase with site depth and site size.
- Individual sites tended to hold approximately the same number of individuals throughout the year.
- There was not a significant seasonal effect on abundance or presence; however, the highest numbers of individuals were observed during the summer months.
- Goliath grouper were measured via underwater videography, and ranged in size from 40 – 205 cm total length (TL). The majority of individuals observed were between 100 -150 cm TL; however, multiple small (< 100 cm) and large (> 150 cm) individuals were also observed throughout the depth range surveyed.
- A total of 172 goliath grouper were fitted with external identification tags, and 27 individuals were resighted or recaptured throughout the study period. Time at large ranged 1 – 713 days. The majority of resighted individuals were observed at the same site as their initial tagging, although fish were documented to move as far as 203 km.
If you'd like to learn more about goliath grouper research efforts, visit:
Florida State University