Published in the Ocean Watch column,
Honolulu Star-Advertiser © Susan Scott

January 22, 2001

It’s easy to get discouraged about going to Hanauma Bay because the news we hear from there is often negative. If there isn’t some controversy about management or development going on, we’re hearing about proposed fees or additional rules.

But no matter what’s going on above the water there, below the water Hanauma Bay is a jewel.

A couple of weeks ago, I went snorkeling at the Bay with my husband, Craig. After swimming outside the reef, we each went our own way along the outside. I soon spotted a large whitemouth moray. The eel helped me identify it by opening its jaws wide and showing its bright white inner mouth. But it wasn’t just the moray’s mouth I saw. This eel was out swimming around.

Usually, moray eels stay hidden during the day and come out at dusk to hunt. Since it was high noon at Hanauma Bay, I expected this roamer to duck into a hole and hide. It didn’t. The fish stayed fully exposed as it moved along the reef probing cracks and crevices for prey.

I followed closely for a long time. Why this big eel was out hunting in broad daylight, I do not know, but watching it do it was thrilling.

When Craig and I reunited, I told him about my eel but he was excited about something else: a school of big silvery fish moving around in a tight circle. “Did you see them?” he asked. “There were 50 to 100. They looked like jacks.”

I had seen them in the distance while following my eel. “I thought they were gray,” I said. “And looked like mullet.”

We shrugged and went home. Three days later, a reader sent me this email: “Today at Hanauma Bay, past the reef in about 15 feet of water, I saw a school of perhaps 80 fish swimming in a tight circle. I didn’t recognize the fish; they were nondescript, silvery gray, about 12-15 inches long. They were swimming in a circle up to about six feet in diameter. Have you ever seen or heard of something like this?”

“We saw them too,” I wrote, “but I don’t know what they are.”

The next day my reader sent this message: “My friend says they were probably Heller’s barracuda.” I told Craig. “No, they definitely weren’t barracuda,” he said. “I think they were jacks.”

I emailed a friend who knows fish well, giving my vague description of a gray mullet-like fish. He passed the query to a Hanauma Bay worker and also to a biologist at the National Marine Fisheries Service (NMFS). Soon, we were all sending messages back and forth with guesses and comments. “Too bad we don’t have a picture,” someone wrote.

A few days later I was surprised to see an email on my computer labeled: Mystery fish named! It turns out that NMFS worker Bruce Mundy went to an underwater slide show and saw a photo of silvery fish swimming in a tight circle at Hanauma Bay. He recognized the species. The fish were, um, jacks.

Specifically, they were bigeye jacks, also called bigeye trevally or Caranx sexfasciatus. When I looked it up, I learned that when not feeding, these fish often congregate in tight schools.

Of the approximate 140 species of jacks (called ulua here), Hawaii hosts 24. Jacks vary in shape according to genus. This body shape variation is my excuse for failing to name even the right family for the mystery fish, but in truth I just wasn’t paying attention. And yes, Craig is gloating.

Hanauma Bay was the first place I ever snorkeled in Hawaii and after 20 years of going there, it’s still showing me a great time. Don’t give up on the place.

2020-07-10T18:50:00+00:00