How Fast Can Mahi Grow?

It Grew How Much?

Article Courtesy of Cooperative Science Servi es, LLC Dolphin Research Project
The DRP has been talking about how fast dolphin grow for many years, but many fishermen and even some fishery managers have not accepted these documented facts. We have spoken of conservative growth rates of 0.5 to 1.0 inch in length per week and gaining two to three pounds per month. This information has been met with skepticism from anglers and fishery managers alike. So here is another documented case of the dolphin’s amazing growth that was brought to my attention by Capt. Ray Rosher of Miami, Florida.
Studies.

The University of Miami’s Rosenstiel School of Marine and Atmospheric Science’s aquaculture program has been studying the culture and propagation of dolphinfish in order to provide larval and juvenile dolphin for other research studies under way at the university. Ron Hoenig, hatchery manager for the RSMAS’s aquaculture program, was kind enough to provide the details surrounding this story.
The male (bull) dolphin was collected from the wild with the help of Capt. Ray Rosher on his boat the Miss Britt off Miami, Florida, on December 19, 2014. The fish was transported to the RSMAS’s Experimental Hatchery located on Virginia Key as part of their captive breeding program and other research initiatives.
At the facility, the fish was maintained under optimal conditions with plenty of food and no predators to avoid. It was fed squid, sardines, herring, and mackerel to satiation (quits eating) once a day, seven days a week. So this fish lived under optimal conditions, which should foster maximum growth.
At the time of its capture, the fish was approximately 5 to 6 pounds. The fish was weighed on digital scales on September 24, 2015, (279 days in captivity) at which time it weighed 56.4 pounds. So in just 9 months this bull had grown 50 pounds. This indicates an overall average of 5.5 pounds gained each month. More than a decade earlier Milt Shedd, co-founder of SeaWorld in San Diego, California, and president of the American Fishing Tackle Company, raised a dolphin in captivity that exhibited similar growth.
It would be unrealistic to expect such growth to be common among wild fish; only a few other bull dolphin in the RSMAS culture study have exhibited somewhat similar growths. Female dolphin in the program have not shown near the growth rate shown by this bull. It does demonstrate the potential growth the species has and suggests that by releasing small fish fishermen can earn dividends in short order in the form of bigger fish.