The Journal of Fish Biology has published the first robust study of the age and maturity of ulua aukea and omilu by Hawaiian scientists. These two trevallies are the most important inshore species targeted for recreational purposes in Hawaii, with many fishing clubs and tournaments devoted to them.
Poseidon Fisheries Research (PFR) scientists studied ulua aukea, or giant trevally (Caranx ignobilis), and omilu, or bluefin trevally (Caranx melampygus), to determine their growth rate, longevity, and life span. maturity.
The researchers collected more than 100 samples of each species from recreational anglers at fishing tournaments, as well as the Pacific Islands Fisheries Group and the Hawaii Division of Aquatic Resources.
Scientists have found that, just like in humans, as these fish age, their size and weight can vary. The oldest ulua aukea weighed 50 pounds and was 31 years old, while the heaviest (80 pounds) was 24 years old. The oldest omilu was 24 years old and weighed almost 14 pounds. The scientists also found that the average size at maturity, a key measure of population, differed between males and females. The female ulua aukea matured at around 23 inches and 4.4 years old, while the males matured at around 18 inches and 2.8 years old.
Omilu reached maturity at around 14.5 inches and 4.1 years for females and 13 inches and 2.9 years for males.
“The data collected on age and maturity will be important for the future management of these highly prized and ecologically important predatory species in Hawaii,” said Cassie Pardee, study co-author and PFR fisheries biologist.
Fishermen camp along the coast, ready to fight one of the toughest fighting fish and hoping to land a fish that can weigh over 100 pounds.
“Ensuring that the best scientific data on ulua and omilu is available for stock assessments will enable fishers to continue to fish sustainably,” added John Wiley, PFR fisheries biologist and study co-author.
Poseidon Fisheries Research is a Hawaii-based fisheries science research team conducting work in the Western Pacific region. Their goal is to fill data gaps to improve our understanding of local fisheries and the biology of associated species.
Ultimately, they strive to provide the best scientific information available so managers can effectively regulate our aquatic resources and ensure sustainable fisheries for future generations.
They work closely with fishing communities, using their local knowledge and expertise to help collect vital data while engaging them in ongoing research.
They seek to bridge the gap between science and anglers, so they can both benefit from each other’s knowledge, work together to protect the waters and keep the harvesting of its organisms responsible.