Mahi-Mahi Welfare: Bycatch, Live Release, and Wild Capture

Mahi-mahi are fast-growing, highly migratory pelagic fish subject to intense recreational and commercial fishing pressure, with welfare considerations around live bait use, bycatch mortality, and live release practices.

Key Facts

Mahi-mahi have one of the fastest growth rates of any fish — reaching 12 kg in the first year
They are caught by trolling, longlining, and FAD (fish aggregating device) fishing in tropical oceans globally
Recreational catch-and-release of mahi-mahi is common but post-release mortality rates are poorly studied
Juvenile mahi-mahi aggregate under floating debris and FADs, creating welfare concerns in FAD-associated purse seine fishing

Welfare Considerations

Mahi-mahi caught on rod and line experience exhaustion, physiological stress, and lactic acid accumulation during fighting. Poorly handled released fish show elevated post-release mortality, particularly in warm water where recovery is impaired. Mahi-mahi bycatch in longline fisheries experience hook injuries and prolonged restrained struggling before being discarded dead or alive. FAD-associated purse seine fishing concentrates juvenile mahi-mahi with tuna at high densities — bycatch mortality of non-target species including juvenile mahi-mahi is significant. Trolling with live bait causes welfare harms to the bait fish used in capture.

What You Can Do

Use best-practice catch-and-release protocols for mahi-mahi: wet hands, minimal air exposure, revival before release
Choose mahi-mahi from pole-and-line fisheries with lower bycatch rates than FAD-associated purse seine
Support ISSF (International Seafood Sustainability Foundation) advocacy for improved FAD management standards
Raise awareness that recreational catch-and-release practices affect fish welfare and post-release survival