Ocean Watch

Monday, January 26, 1998

The sea bass and hapu‘u
are grouped as groupers

"WHEN my father was living, he always purchased from the Chinatown fish markets a white-flesh fish pronounced in Cantonese loong dun," writes a Honolulu reader. "It is a delicious fish which we eat raw, sashimi style, or cooked with jook (Chinese rice porridge). Could this fish be the Hawaiian sea bass or grouper which the Hawaiians call hapu'upu'u?"

I called a Hawaii friend who grew up in Hong Kong. "Sea bass," he said immediately when I read the name. "In Hong Kong they also call it corupa or dragon fish."

At a local Chinese restaurant, I mentioned loong dun. "Sea bass," said the owner. "It's a big fish. We serve it for banquets."

OK, so loong dun is sea bass. But what is a sea bass?

Sea bass is the food or menu name for a family of marine fish called groupers.

Groupers are bottom fish, lying in wait near the ocean floor to ambush passing fish or invertebrates.

When a likely meal gets close, the grouper opens its expandable mouth and inhales, sucking in both water and prey.

As you might suspect, this action takes place with lightning-strike efficiency.

Large groupers have been found with lobsters, stingrays, puffer fish and even sea turtles in their stomachs.

The grouper family is large, but not many types made it to Hawaii: Only two species are native here.

One is the kind mentioned in the above letter, the hapu'u (hapu'upu'u means the young or juvenile of the species), also called the Hawaiian grouper. Its scientific name is Epinephelus quernus.

Adults grow from 2 to 3 feet long and usually swim in deep water. Hawaii's anglers fish for hapu'u by dangling baited lines over the side of the boat in about 300 to 700 feet of water.

Hawaii's other native species, the giant grouper, is now exceedingly rare. In 1989, a 554-pound giant was caught off Kihei, Maui, but this was a highly unusual catch.

Groupers are vulnerable to overfishing for several reasons. One is that they eat fish themselves; therefore, fish shortages affect them directly.

A second vulnerability is that large species grow slowly, sometimes taking several years to reach sexual maturity.

Another factor making groupers susceptible to fishing pressure is their sexual orientation: These fish are sex changers, beginning mature life as females, then later changing to males. Removing most big groupers from a population leaves few males in that area to fertilize eggs.

Because of these factors, groupers are rare or absent from heavily fished areas but conspicuous in protected areas. Several times while diving in protected waters of Australia, I have had tame groupers over 6 feet long swim right up to me and pose for some gentle petting.

Because Hawaii is short of groupers, the state brought in several species from Tahiti in the 1950s. One lovely fish, the roi, or peacock grouper, adapted well. Unfortunately, since it lives on reefs, the species often carries ciguatera and therefore is not a reliable food fish.