Dolphinfish research dives deep to improve FAD fishing

Dolphinfish travelling up to 600 kilometres in just three weeks and diving to depths of more than 500 metres are among the findings of new research helping scientists better understand the movements of one of Western Australia’s most popular pelagic species. 

DPIRD scientists are tracking dolphinfish – sometimes called mahi mahi – using acoustic and pop-up satellite tags to learn more about where the fish travel, how deep they go and how their movements change throughout the year.

Check out the video below to watch the tagged dolphinfish’s movements off Perth’s coast.

The research could ultimately help fine-tune the timing and placement of FADs to provide better fishing opportunities. 

DPIRD Research Scientist Peter Mitchell, who is leading the research, said dolphinfish tagged around several metro FADs between March and May had already produced some surprising results. 

“It’s a lot deeper than we thought these fish go,” Peter said, with tagged fish generally spending most of their time near the surface but periodically diving beyond 100 metres, likely to feed.  

One fish was recorded reaching an extraordinary depth of 516 metres. “The purpose of this research is to understand where the fish are and at what time of year they’re moving so that we can better structure the FAD season so they’re most attractive to the fish and a better fishing resource.

“The more we can learn about the movements and behaviour of fish like dolphinfish, the better we can refine the FADs program to maximise sport and game fishing opportunities.” 

Recfishwest Operations Officer Levi De Boni welcomed the research and its potential to further improve the FADs program. 

“It’s great to see research focused on improving such a popular fishing initiative and delivering even better experiences for fishers,” Levi said. 

“FADs have made pelagic fishing much more accessible in recent years, and we want to see continued investment and innovation in the program. 

“Recfishwest’s role is to help ensure FADs are deployed in the right places at the right times to provide the best possible fishing opportunities. This research will provide valuable information to support that.” 

The research comes as the State Government invests $1.9 million over two years to continue the FADs program, supporting more opportunities for fishers to target pelagic species including dolphinfish, tuna, wahoo and marlin. 

The program was originally pioneered by the Perth Game Fishing Club before Recfishwest delivered a Recreational Fishing initiative-funded three-year statewide trial that helped establish the network enjoyed by fishers today. 

Read more about the FADs program here  

The State FADs network now includes 48 devices deployed along the Western Australian coast between Broome and Albany. 

The 36 southern FADs are generally deployed from December to May, while in the north four seasonal FADs are deployed off Exmouth from March to November and eight reinforced FADs remain in the water year-round off Broome and Dampier. 

The dolphinfish tagging program will continue through the 2026-27 season, building a bigger picture of how these fish move through Western Australian waters and providing valuable information to help shape future FAD deployments. 

• DPIRD has asked that anyone who catches a dolphinfish with a pop-up or acoustic tag in it to contact the Department.