Abundance of Mahi-mahi unknown

Mahi-mahi (Coryphaena hippurus), also known as dolphin-fish, dolphin or dorado, are surface-dwelling fish found in off-shore tropical and subtropical waters world-wide.

Mahi-mahi is often thought of as a Hawaiian fish, but it is also found in warm waters around Florida and along the Pacific Coast. They are one of only two members of the Coryphaenidae family, the other being the Pompano dolphinfish.

The name ‘mahi-mahi’ (meaning ‘strong-strong’ in Hawaiian) has been adopted in recent years to avoid confusing these fish with dolphins, which are mammals.

Mahi-mahi are carnivorous, feeding on flying fish, crabs, squid, mackerel and other small fish. They have also been known to eat zooplankton and crustaceans.

At first, most Mahi-mahi were a by-catch (incidental catch) in the tuna/swordfish longline fishery. Now they are sough after by commercial fishermen off the Pacific Coast of Latin America, from Peru to Costa Rica; the Ecuadorians have a growing fishery. Recreational anglers also catch mahi-mahi offshore in the Atlantic Ocean from New Jersey to North Carolina and farther south.

Seen in the water, Mahi-mahi has a characteristic blunt head and striking blue-green and yellow scales. Mature males also have prominent foreheads protruding well above the body proper.

When they are removed from the water, the fish often change between several colors, finally fading to a muted yellow-grey upon death. Its flesh is dense and moist, with a mild, slightly sweet flavor.

Generally, smaller dolphin fish range from 2-5 pounds, while 40-50 pound fish are not uncommon. Dolphin fish have a short life span of three or four years.

Their swimming speed is estimated at 50 knots, they spawn in warm ocean currents multiple times each year and their young may be found in sargassum weed.

Mahi aggregate around floating objects, making them easier to locate. Consequently, fishers can use attracting devices including cork planks, or floating bundles of bamboo reeds to concentrate fish.

No formal evaluations have been conducted for this fishery therefore there is limited information available on the abundance of Mahi worldwide.

In the U.S., there is no statistics program in place that is specifically aimed at sampling the species, and international agencies that monitor other highly migratory species (such as the International Commission for the Conservation of Atlantic Tunas) have not measured the abundance of Mahi.

The only available report is an exploratory evaluation of Mahi based on U.S. landings from the Atlantic Ocean and Gulf of Mexico.

The U.S. National Marine Fisheries Service classifies the stock status of dolphinfish as not overfished and overfishing not occurring.

Long-term trends in dolphinfish abundance are unknown, however short-term trends indicate increasing biomass, but these findings are highly uncertain.

Fishermen primarily use longlines and hook-and-line gear to catch Mahi-mahi. There is considerable concern about the type of bycatch from longlining.

Leatherback and loggerhead sea turtles, seabirds, sharks and marine mammals get caught or entangled in longline gear, often resulting in injury or death.

If you can find it, hook-and-line or troll-caught Mahi-mahi is a more eco-friendly alternative because there is very little bycatch.

Cayman Sea Sense is dedicated to helping consumers make informed and environmentally positive seafood choices. For more information on this and other seafood options please visit www.nationaltrust.org.ky/seasense.html or contact [email protected].