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Dolphin—General Facts

Dolphin, Coryphaena hippurus, is an important fishery species in tropical and temperate waters worldwide.

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Dolphin, Coryphaena hippurus, is an important fishery species in tropical and temperate waters worldwide. Dolphin, also known as mahi mahi, are usually found well offshore, but can occur within a few miles of the coast when winds blow steadily onshore or the Gulf Stream is close to shore. Dolphin can be caught along Florida's coastline, but are concentrated in the southeast region of the state. At times, schools of smaller dolphin can be found congregating beneath any object floating in the water such as wood or mats of Sargassum weed. Larger males tend to be more solitary. Dolphin are considered to be dimorphic, males and females differing in appearance, because the males develop a large, bony crest on their forehead but females do not. The dolphin's brilliant color patterns of blues, greens, and yellow, its fierce fighting ability once hooked, and excellent table fare make them a high profile fish species in Florida.

Since 1986, Florida's anglers (both commercial and recreational) have landed between 5.65 and 17.0 million pounds of dolphin annually. Florida's commercial fishery alone had an ex-vessel value of 1.5–2.0 million U.S. dollars annually, but this represents less than 10% of Florida's total dolphin landings (in pounds). Dolphin are the top species targeted by Florida Atlantic coast anglers interviewed by the Marine Recreational Fishery Statistical Survey, making this much larger recreational fishery arguably one of the most valuable fisheries to the state of Florida.

The life cycle of dolphin is quite remarkable. Dolphin are extremely fast growing, but short-lived. Most dolphin only live a year or two, but the oldest fish can live up to around 4 years of age. Maximum size attained by can be up to 5 or 6 feet (1.7 meters) and almost 90 lbs (40 kg). Dolphin fuel this fast growth rate, in excess of 3 feet in the first year, by eating mostly fish, particularly flying fish, mackerels, jacks, leatherjackets, and occasionally other dolphin. Dolphin are also capable of spawning during their first year of growth and may reproduce several times during a single spawning season.

This unusually fast growth rate and high turnover may make dolphin less susceptible to overfishing than other longer-lived, slower maturing fish. Still, management regulations are needed to help conserve this valuable fishery, currently in Florida recreational anglers are allowed to keep 10 dolphin per person per day with no closed seasons or size restrictions. This population is too valuable to put at risk by relying on available information, most of which has not been updated since the 1960s. Scientists at the Fish and Wildlife Research Institute are re-examining the age and growth and reproductive biology, using new technologies. Dolphin samples are currently being collected from the Florida Keys, Indian River, and Northern Gulf of Mexico. Information to be determined includes how long do dolphin live, how fast do they grow, when and how often do they spawn, how many eggs they can produce in a year, and a description of the genetic population(s) found in Florida's waters.