Monthly Archives: May 1997

Memorial Day kicks off isles’ summer season

Published May 26, 1997 in the “Ocean Watch” column, Honolulu Star-Advertiser ©1997 Susan Scott

The first day of summer has arrived. I know it’s not official, but traditionally, Memorial Day weekend kicks off the summer season. I, for one, am glad it’s here.

Most visitors laugh when we Hawaii residents talk about summer and winter, like it’s some kind of joke. But those of us who live here feel seasons as acutely as people everywhere else.

Take the water temperature. Last week, I went windsurfing in Kailua and as I backed my gear out through the shorebreak, the water felt warm on my legs. Ah, what a relief it was compared to the chicken-skin water of winter. And it’s going to get even warmer.

At the extremes, the highest water temperature in Kaneohe Bay in August is 84 degrees F. Compare that to its lowest of 68 degrees F in February. The average temperature difference of Hawaii’s summer and winter water is less, about 10 degrees (approximately 80 in summer and 70 in winter). But even those few degrees can make all the difference. It’s what keeps many Hawaii residents out of the water in winter.

Hawaii summer is heralded by other signs. I can tell it’s summer because the shorebirds are gone. By Memorial Day, our beaches and parks are empty of golden plovers, ruddy turnstones, wandering tattlers and sanderlings that so brighten our lives all winter. These migratory birds have flown north by now, to find mates and raise families.

Our humpback whales also have gone north for the summer, taking their new calves with them to feed on the abundant krill of the nutrient-rich northern waters.

I’m glad the birds and whales are gone because of the thrill they give me when they return.

Spotting the first shorebird in late summer is the Hawaii equivalent of the first leaves turning color; seeing a humpback is like the first snowfall.

The departure of these north-feeding animals means the breeding of others. Hawaiian monk seals are having their pups about now and roly-poly albatross chicks at Kaena Point are getting ready to fledge.

Even with the whales gone, I enjoy gazing out at the summer ocean from my North Shore home. It’s flat and calm there now, a sharp contrast from the boisterous surf that dominates the community in winter and deposits salt onto everything.

During the summer I can explore Oahu’s north shore waters in peace. I enjoy walking the wide beaches and snorkeling the tranquil reefs.

I do miss the big surf and the scene it creates, but I know where to go for my summer surf fix: I visit my boat in the Ala Wai Boat Harbor. While there recently, I noticed the boat rocking in its slip and straining on its mooring lines to the rhythm of storm surf from the south. And the commotion in the parking lot told me that the surfers have migrated south for the summer.

Probably the best thing about summer in Hawaii for me is the strong and steady tradewinds. I’m tired of all those Kona winds from last winter that raised the humidity and dumped rain on so many of our beach outings.

June, July and August, Hawaii’s famous northeast tradewinds blow from 91 percent to 95 percent of the time.

The joys of summer ride on these winds. They make channel crossings a true adventure, and windsurfing a challenge. They send warm breezes through our homes during the day and cool our nights for sound sleeping.

Summer in Hawaii does have its drawbacks. Here, at about 21 degrees latitude, the sun passes directly overhead twice each summer, once about now and another time in July. During these close encounters with the sun, our UV exposure is at the max and we burn more easily than any other time of the year.

The feel and smell of sunscreen goes with summertime in Hawaii. And the livin’ is easy.

Hawaii waves variable as they are powerful

Published May 19, 1997 in the “Ocean Watch” column, Honolulu Star-Advertiser ©1997 Susan Scott

< p style=”margin-top: 3; margin-bottom: 0;”>I recently met a woman from New York who impressed me with her fitness. When we went bike riding up a steep road in the Waianae Mountains, she dusted me. A day or two later, when I asked her what she had been doing, she said, “I wanted to go windsurfing, but there was no wind. So I went jogging, then swam a mile or so at Ala Moana Beach Park.”

Wow, I thought. This woman never stops.

A day or so later, however, things took a turn: The woman’s Hawaii friends took her surfing for the first time, in Waikiki.

A couple of hours later, she returned to the Ala Wai Boat Harbor alone. “How did you do?” I asked her, fully expecting her to tell me she stood up and rode 50 yards on her first try.

“I didn’t even try it,” she said.

“Why not?”

“While we were paddling out, the waves breaking in front of my face scared me. I got so scared, I started crying,” she said, wincing. “So I turned around and went back to the beach. The guys went out by themselves.”

She looked out at the surf, nearly flat at the moment. “I can’t believe I was so afraid.”

Ah, yes, I thought, Hawaii surf, the great humbler. But I didn’t gloat. Sometimes I’m afraid of the waves too.

Being leery, or at least respectful, of Hawaii’s surf is reasonable. By their nature, these transfers of energy from water to air can be as variable as they are powerful.

With the exception of tsunamis, wind generates all ocean waves. At their place of origin, wind whips the water into a jumbled mass of chaotic waves.

But these waves don’t stay put. Instead, they move away from their birthplace in humps of water called swells. Since long waves (measured from crest to crest) move faster than short waves, swells, as they travel, sort themselves according to size.

This sorting process is never complete, a fact easy to see at the beach where swells arrive in groups called sets. The intervals between the sets are called lulls.

Sets and lulls vary in size and frequency according to several factors: the speed and duration of the wind that created them, and the distance they have traveled, called fetch.

Water depth determines when swells become breakers. When the depth is less than half the wavelength, waves begin to “feel” the bottom. This slows them down and humps them up. Large waves feel the bottom sooner – that is, in deeper water – than short waves.

The variation in these rolling walls of water can surprise even the most seasoned old salt.

Of course, Hawaii’s surf is not entirely unpredictable. We have some major clues.

During the winter, large waves arrive on Hawaii’s north shores because winter storms in the North Pacific create strong winds. Large south swells occur in Hawaii’s summer for the same reason: It’s then winter in the southern hemisphere, and southern winter storms also generate strong winds.

Since little land lies between Hawaii and these storms, the waves created by these high winds come rolling unimpeded across the ocean until they reach our shores and break.

Calling the height of Hawaii’s waves is another story. Officially, wave height is determined by taking the average of the highest one-third of waves. This method is used for channel and buoy reports.

Hawaii’s surfers and other wave riders, however, measure waves on a different scale, based on local tradition. By this convention, “6-foot” surf is considerably higher than 6 feet.

After my talk with my New York friend, I glanced out to sea. Big waves were breaking outside the Waikiki reef, and several surfers were hurrying to ride them.

I see the appeal. But I also understand the fear. Some days, the best place to enjoy Hawaii’s waves is from shore.

 

Exploring the wonders of Waikiki’s wildlife

Published May 12, 1997 in the “Ocean Watch” column, Honolulu Star-Advertiser ©1997 Susan Scott

I’ll never understand some people’s aversion to Waikiki. Its wide walkways make for pleasant strolls, people-watching is great there, and those ocean sunsets are the picture of Pacific romance. Also, although most people don’t realize it, some of Hawaii’s best wildlife appears in Waikiki.

Last week, I had a meeting at the Diamond Head end of Waikiki and decided to walk there from the Ala Wai Boat Harbor. Before my feet even touched sand, I was stopped by a flash of brilliant orange and blue among the rocks near a boat.

I stopped and waited. Soon a tiny orange fish face peered from its hiding place. Then a second bright fish darted from one hole to another. The fish didn’t give me much time to identify them, but I know these beauties: They’re Potter’s angelfish, one of Hawaii’s six “pygmy angel” species.

Angelfish in other parts of the world are often big and bold, providing divers with memorable close encounters. Not Hawaii’s pygmy angels. Ours are shy little things, spending most of their time close to cover, venturing out only to graze warily on nearby algae.

My presence spooked these angels of the Ala Wai, and they remained mostly hidden while I stood there. That was OK, though. I now had their address.

I moved on. As I rounded the lagoon of the Hawaiian Hilton Village, I was stopped by the sight of a sea bird diving for fish just feet offshore, near the breakwater. The big bird would fly in a wide circle around the area inside the reef, then tuck its wings and drop like a sleek torpedo head first into the water. A second later, the bird would pop up, swallow its fish meal, then take off and do it again.

I walked to the edge of the water and squinted at the soaring bird, noting its brown body and its white breast, beak and feet: It was a brown booby, one of three booby bird species found in Hawaii. (The others are masked and red-footed boobies.)

Brown boobies love to sit on navigation buoys. I often see them from my kayak sitting like sentinels on the big red and green seaward markers of the Ala Wai channel. And just yesterday, a friend told me that several of these birds were balancing on the buoy off the Haleiwa Boat Harbor.

It was hard to leave this bird during its fishing frenzy, but I had places to go. I stayed as long as I dared, then continued down the beach.

When I reached my destination at Kuhio Beach, I found Rob Miller, the lifeguard I was meeting, showing a captured box jellyfish to a crowd of beach-goers. He held the creature by its bell, the safe part to touch, and explained the dangers of the trailing tentacles.

Visitors were fascinated. We all talked at length about how these animals sting people by accident when the creatures get caught inshore. Also, that the sting is not lethal, as it is with some species of box jellyfish in Australia.

After my meeting with Miller, I hurried back to the boat to get some writing done. But back at the Hilton, I was stopped yet again. The brown booby, more than an hour later, was still fishing up a storm.

OK, I had to see what the bird found so delicious this close to shore amid all these people. I ran to my boat, changed into my swimsuit and hurried back with mask and snorkel.

The bird was gone. But what the heck. I went snorkeling anyway. And there I saw something new to me: A goatfish, so large I first mistook it for a mullet, was excavating an enormous hole in the sand, its chin whiskers (called barbels) digging like mad. Apparently, the fish sensed some goody deep in the sand and was determined to get it.

I watched for a while, then visited a school of needlefish I know. By the time I got back to the boat, my workday was pretty much shot.

People come from all over the world to while away time in Waikiki. I have only to walk to a meeting.

 

Marine biologist Susan Scott writes the newspaper column, “Ocean Watch”,
for the Honolulu Star-Bulletin, www.starbulletin.com

Hot tuna:  Northern and Southern bluefins

Published May 5, 1996 in the “Ocean Watch” column, Honolulu Star-Advertiser ©1997 Susan Scott

Ted Farm, a longtime reader from Ewa Beach, wrote recently, asking a question about tuna. It’s a hard one. Ted wants to know why Atlantic bluefin tunas grow five to six times larger than Pacific bluefin tunas.

To answer this question, I first had to learn about bluefins in general. These famous giant tunas come in two species, but not Atlantic and Pacific, as I first thought. Rather, there are Northern bluefins and Southern bluefins, separated by Earth’s north and south hemispheres.

The scientific name for the bluefins of the south is Thunnus maccoyii. These fish spawn in one large area off the west coast of Australia. From there they swim throughout the Indian, South Pacific and South Atlantic oceans.

The record weight for a Southern bluefin is 348 pounds. It was caught in New Zealand waters in 1981.

OK, now we head north. The bluefins up here, both in the Atlantic and Pacific, are all the same species: Thunnus thynnus. (Scientific names are important here because common names vary throughout regions.) These tunas of the north have three spawning grounds: The Atlantic fish spawn in the Caribbean or the Mediterranean, the Pacific fish near Japan.

The biggest Northern bluefin on record weighed a whopping 1,496 pounds. It was caught in 1979 off Nova Scotia.

This makes the biggest Northern species about four times larger than the biggest Southern. But how do Northern bluefins of the Pacific compare to those of the Atlantic? They’re smaller, but not much smaller.

According to researcher William Bayliff of the Inter-American Tropical Tuna Commission in La Jolla, Calif., Pacific bluefin tunas have been caught off both Japan and Southern California in the range of 1,000 pounds, give or take 50 or so pounds.

That, of course, isn’t the average catch size. One Hawaii fish book says most Pacific specimens are in the 250-pound range. Last week, however, the United Fishing Agency (which runs the Honolulu fish auction) sold a 517-pound Pacific bluefin caught by a long-liner. “It was one of the larger bluefins we see here,” a spokesman said.

Most Atlantic bluefins don’t approach their 1,500-pound record either. Catches usually weigh in the several-hundred-pound range.

Still, these numbers show that Ted Farm is right: The Pacific bluefins don’t appear to grow as big as the Atlantic stock, though they’re the same species. Why?

“It’s not uncommon for members of the same species to be different sizes in different regions,” said Bayliff. “King salmon are enormous in British Colombia and smaller in Alaska.

“Another example that comes to mind are people. Pygmies are smaller than Europeans, yet we’re certainly all the same species.”

This genetic variation among races occurs during the process of evolution because somehow the change is to the group’s advantage.

So, how does being somewhat smaller than the rest of the species benefit Pacific bluefins? No one knows.

During my search for an answer, I learned a lot of other interesting facts about bluefin tunas.

Only about 20 years ago, Atlantic bluefins, also called horse mackerels, were worth about a nickel a pound and fed to cats. During fishing tournaments, these giant fish were hauled up the scales as trophies, then thrown out either at sea or in the town dump.

That’s quite a contrast to the late ’80s when other tuna stocks got low. Now, raw bluefin meat can sell for up to $50 a pound, making a 1,000-pound fish worth $50,000.

The results of this bonanza were inevitable. Today, most researchers agree that the stocks of Southern and Northern Atlantic bluefins are seriously depleted. However, according to Bayliff, the Northern Pacific stock appears to be holding its own.

I wonder how long it will last.