It’s ono season on Maui
Wahoo, better known in Hawaiian waters as ono, are the biggest, fastest and meanest mackerel in America. It can reach speeds of up to 45 miles per hour in short bursts, allowing quick capture of prey species.
What exactly is a wahoo? It is a unique member of the tuna family called Scombridae — a “tribe” line of the tunas and mackerels called seerfish. That “tribe” contains the 18 species of Scomberomorus (king and Spanish mackerels) around the world, with the unique wahoo in its only species, Acanthocybium solandri.
Even the names, both common and scientific, are interesting. In 1769. the crew on James Cook’s Endeavour, north of Tahiti, caught the first of these speedsters to be recorded in the western world. It was scientifically named (Solandri) to honor the great Swedish scientist on board the Endeavour, Dr. D.C. Solander.
The name “wahoo” logically dates from the early whalers and missionary settlers seeing and utilizing the fine edible species in the Hawaiian Islands. Then and now, Oahu, which they pronounced and sometimes spelled “Wahoo,” was an important base. The Hawaiians had long recognized the quality of wahoo with their name “ono,” meaning delicious or tasty.
They grow fast, attaining a length of three-and-a-half feet the first year. Two- and three-year-olds are five feet long. The maximum reported size for the wahoo is 98 inches (over eight feet) total length, with a maximum weight of 184 pounds. This is the current IGFA all-tackle record held by a woman at 184 pounds, on 80-pound test, from Cabo San Lucas, Mexico. The Hawaii state record is 133.2 pounds off Pohoiki, Hawaii. The Lahaina Harbor record is a 90.2-pound ono that was 69 inches long.
Typically, individuals attain a size of 39 to 66 inches. After reaching a length of 38 to 41 inches, individuals grow at a rate of 1.2 to 1.5 inches per month. Latitude appears to influence size, with average weight increasing with distance from the Equator, apparently correlated to cooler temperatures.
Wahoo are sexually mature at one to two years of age. They usually live to about six years of age but can live longer. Wahoo start breeding at one year old. Female wahoo are very fertile, averaging approximately 40,000 mature eggs per two pounds of body weight. Females can produce up to 60 million eggs during spawning, and the larvae are pelagic and prefer shallower water less than 300 feet or so. Babies are two-thirds fish and one-third alligator. Wahoo spawn year-round in tropical waters and during the summer in higher latitudes, including Hawaii, when sea surface temperatures are over 75 degrees Fahrenheit. Individual wahoo spawn multiple times throughout the spawning season.
The condition and abundance of wahoo appear to be related to a simple annual reproductive cycle. The condition of wahoo is highest in May before the spawning season and declines through the spawning season, reaching a minimum in July-August. Catch peaks in summer, during the spawning season, suggesting that wahoo may gather near the islands to spawn.
Migration related to reproduction may also explain some of the seasonality in catch rates of wahoo near the Hawaiian Islands. It appears that wahoo migrate from the open ocean to the islands and banks to reproduce, then leave the islands and banks to feed in the open ocean.
Surface currents and eddies generated in the island wakes are mechanisms that could transport larvae and juveniles to the open ocean.
A limited amount of spawning could also occur offshore. However, a move to nearshore waters in May for spawning throughout the summer would be consistent with the increase in condition and catch rates in the nearshore fisheries.