Hawaii Sea Bass is commonly called hapu‘upu‘u in Hawaii and grouper in other markets. This species is only known to occur in the Hawaiian Islands and at seamounts just northwest of Hawaii. Members of the grouper family are able to change skin colors to blend into their natural habitat, and the hapu‘upu‘u is no exception. Most hapu‘upu‘u seen in the market are black, but fish captured in certain locations may be brownish or reddish.
The largest landings of hapu‘upu‘u usually occur from October-December and February-April. The majority of the hapu‘upu‘u catch in recent years has come from the Northwestern Hawaiian Islands. Most of the hapu‘upu‘u caught off the main Hawaiian Islands are from 5 to 10 pounds in size, whereas the waters around the Northwestern Hawaiian Islands range from 10 to 30 pounds. This delicious fish is popularly consumed steamed.
Hapu’upu’u are a coral reef fish that seek protection and food in the crevices and caves provided by reefs, especially when they are young. They lay eggs that float to the surface after being fertilized by the sperm released by the male in the water column during mating. The small hapu’upu’u larvae that hatch from these eggs float in the ocean for a period of time, at the mercy of the ocean currents. They then metamorphose into small groupers that eventually swim to the bottom and hide between the corals or seagrasses.
Interestingly, hapu’upu’u go through a process called sequential hermaphroditism; when they reach sexual maturity they are female, but after they mate and produce eggs, they change sex and become male. The trigger for the transition is not clearly known, but probably has something to do with population pressure and presence or absence of other males.
This fishery uses a variety of artisanal hook-and-line methods to catch coastal pelagic fish such as tuna, marlin, swordfish, mahi mahi, wahoo (ono) and others. A pole and line with live bait scattered into the water is used to catch feeding skipjack tuna. Trolling with lures and lines, and handlines with lures, lines and bait bags are used to target larger fish such as bigeye tuna, swordfish, mahi mahi and wahoo.
Deep-sea Rod & Reel
This fishery uses rods and reels to catch six species of snapper and one species of grouper that are called “bottomfish.”