This article appeared in Wildlife Journal in the winter 2000 edition. It received the second place 2001 OWAA Excellence in Craft award in the Conservation/Environment Magazine category.

Every angler and crewman aboard the Wave Runner knew that the fish was huge. As a warning clicker on the massive gold reel began to shriek, a 375-pound giant bluefin tuna stripped off 200-pound-test-line from the reel as if it were dental floss from the reel.

“Fish On!” screamed the captain, yelling to be heard above the ship’s droning diesel engines.

Bob Walmsley dove into the fighting chair. By previous agreement, Bob, a 65-year-old law-firm manager from Georgia, would take on the first fish. His brother and fishing partner, Don, would work the chair. Six-foot-seas and the frigid January dawn off the North Carolina Coast offered less than optimal conditions. Nonetheless, the brothers entered the battle with gusto, hoping to capture not just a fish, but a victory for marine science and a bit of their youth as well.

Half a century earlier, Bob and Don had helped their father land a giant bluefin tuna off the coast of New Jersey. At that time, in 1950, it was the largest bluefin tuna ever landed in Jersey waters and the experience had since lured the brothers into a lifetime of big-fish adventures around the world. However, the one fish that had consistently eluded them was the same species that now threatened to rip Bob Walmsley from his deck shoes.

These days, if a person wants to catch a giant bluefin tuna – which can weight 1,500 pounds and swim nearly 40 miles per hour – the best bet is to head, like the Walmsley brothers, to the waters off Morehead City, N.C. During the last five years, offshore anglers and marine biologists alike have been awed by the sheer numbers of giant bluefin spending the winter there, a phenomenon that previously had either gone unnoticed or was nonexistent.


Each winter, thousands of giant bluefin tuna now gather within sight of the beaches of Cape Lookout and Cape Hatteras, concentration in numbers unimaginable elsewhere and creating a remarkable sport fishery. From December through February, when recreational fishing for the giants peaks, hookups of dozens of fish each day weighing up to 1,000 pounds apiece have angler sweating in the frigid ocean air.

Scientists, too, have taken a keen interest in this schooling phenomenon. Annually, they team up with dozens of anglers like the Walmsleys to harvest information about one of the sea’s most impressive creatures. Under a cooperative program, known as Tag-A-Giant (TAG) anglers pay $1,000 apiece for the privilege of sponsoring a space-age tag that will be inserted into any fish they catch. From this, scientists can track via a satellite the movements of each fish after release, over the seasons building a composite picture of a population in serious decline.

With a price tag on their heads of many thousands of dollars per fish at markets in Japan, giant bluefin tuna have been over-harvested by the combination of intense commercial fishing pressure and inconsistent international regulations. Current management plans are implemented through the International Commission for the Conservation of Atlantic Tunas and are primarily based on statistics from the commercial catch.

Though sport regulations allow a limited retention of some giant bluefin, most caught by recreational anglers are released. Thus by working with those anglers, TAG scientists hope to gather information necessary to formulate a more comprehensive management plan to ensure the future of these magnificent fish.

First, however, the anglers have to catch them. At the end of the giants first run, Wave Runner mate Chris Johnson increased the reel drag to 70 pounds of tension and handed Bob Walmsley the rod. While Johnson reeled in the other trolling lines, the fiberglass rod in Bob’s hand bowed nearly to the point of splintering.

With the fish in full fight, Don Walmsley kept the chair positioned so Bob could face the brute directly. A stiff northeaster tore whitecaps off the sea swell as Captain Pollack maneuvered the bow of his 53-foot Jarrett Bay sportfisherman into the crests. Standing 6-foot-4 and wearing a yellow rain suit, Pollack held fast in the swaying tower and shouted encouragement to the spray-soaked men below.

Several times during the battle, the fish lifted Bob Walmsley from the chair. A short, slightly built man, Bob did not have the body mass to counterbalance the fish. Fortunately, the road was strapped to the chair’s base and what Bob lacked in size he made up for in doggedness. Each time the giant hoisted him in the air, he used his weight, his leg muscles and the boat’s engine to tire the fish enough to sit down again.

Years earlier, Bob’s fighter plane had been shot down on his 99th mission over Vietnam. The crash had cost him much of the strength in his right arm and leg and at times he was forced to use both hands to turn the reel handle. Several times he accidentally bumped the reel’s drag lever back down to strike weight, and the fish ran off hundreds of yards of line each time. Each time, his brother, Don, was quick to slide the drag lever forward to 70 pound again. Although the fish threatened to get the best of Bob, within a half hour, the leader was finally in the mate’s hands.

Once a fish is at bay, the challenge than turns to science. In an adjacent “surgery” boat, the Calcutta, Captain John Jenkins maneuvered into a stern-to-stern position with the Wave Runner. As choppy seas purged her deck, a team of scientists eagerly waited to take measurements of the captured fish and implant the all-important tags.

A mate aboard the Calcutta tossed a tennis-ball rig to the cockpit of the Wave Runner. The ball carried a line from the second fighting rod, which was clipped to the leader holding Bob’s fish. Bob Walmsley’s line was then severed and he sat back panting steam into the frigid air.

Aboard the Calcutta, the crew wrestled the fish through a stern door and up a stainless steel ramp, guiding the monstrous fish on deck.

Scientists worked quickly to implant the special “pop-off” tag, a device programmed to disconnect months later, float to the ocean’s surface and transmit via satellite the information it has collected. From this, scientists will learn how deep the fish swam, where it traveled and obtain a continuous record of the water temperature and the tuna’s internal body temperature.

Indeed, TAG is a big science for big fish. Launched in early 1996, the program now involves Stanford University and Monterey Bay Aquarium in California and the Duke University Marine Lab in North Carolina, among other state, federal and nonprofit auspices. Dr. Barbara Block, a professor of marine science at Stanford University, heads the program.

Petite and raven-haired, Block is dwarfed by the fish as she goes about here work in the cockpit of the Calcutta. She takes notes while snapping orders to the surgery team in a no-nonsense tone. Getting information is tantamount only to getting this fish back in the water as soon as possible, and it is an efficient process, a model of coordination between sport and science.

Although most anglers participate out of a sense of conservation, there are also prizes involved. The 1999-2000 event offered an all-expenses-paid marlin-fishing trip to Hawaii for the sponsor’s fish that swims the farthest after tagging. There was also a reward for the sponsor of the first “pop-off” tag to transmit from the Gulf of Mexico. All anglers would receive information about the tags they sponsored and anyone sponsoring two or more tags was entitled to a trip aboard a surgery boat.

Few, however, are in it for the prizes, and the $1,000 sponsorship fee from anglers is less an effort by TAG to offset costs than to encourage interested people to become involved. According to Bill Hitchcock, coordinator of North Carolina’s TAG program, the cost of each pop-off tag is actually $7,000.

At a dinner function the evening before the event, Hitchcock, slim and soft-spoken, is almost invisible among dozens of volunteers munching crab dip and talking giant tuna. Pulling away from two boat captains and a school of scientists, Hitchcock says, “Most of the program is paid for by grant money, which is often scarce. Scientists and anglers come to North Carolina for the TAG event at their own expense. We have anglers and scientists who come from as far away as Hawaii and New Zealand to sample the fabulous fishing as well as to help out with TAG.”

However, according to Hitchcock, TAG really needs more industry involvement. “Fishing tackle manufacturers, boat manufacturers and charter boat owners should be some of the best sources of funding through sponsorships because they have the most to gain by the success of the program,” he said.

For his own part, Hitchcock got involved in TAG after his company, Hitchcock Broadcasting, taped some shows about giant bluefin tuna fishing.

“Now I coordinate anglers, scientists, media and boats,” he said. “I became hooked on the program because it is pure science.”

Despite the sophistication of that science, there are still many unknowns about the world’s stock of giant bluefin tuna. For one thing, scientists still do not know whether the giants have always wintered in this area of the Atlantic Ocean, or whether the phenomenon is a recent occurrence.

At a laboratory session at the Duke University Marine Science Lab in Beaufort, N.C., after a day of tagging, biologist Block used satellite photographs to point out an eddy of warm water swirling into the Cape Lookout area from the Gulf Stream. The fantastic fishing for giant bluefin tuna near the North Carolina Coast started six years ago, when scientists speculate that this huge current first appeared.

According to Block, the eddy could have been created by the same global weather patterns – El Nino and La Nina – that are theorized to have steered numerous hurricanes toward this same area in recent years. Or the current, and the fish, may have been here all along.

If and when the eddy disappears, it is possible that the fish will move farther offshore. Thus, no one knows if the giant bluefin tuna will continue to be a wintertime fishery in the state’s future and provide the working laboratory for marine science to better understand the species.

Current commercial harvest regulations are based on the theory hat there are two breeding populations of giant bluefin, one in the Mediterranean and one in the Gulf of Mexico. That theory allows commercial take from both populations under a less-than-unified management plan; when the season is closed on one population, the pressure simply shifts to the other.

However, scientists like Block are working on the theory that there is only one breeding population of giant bluefin and are hoping to establish a coordinated, worldwide management plan.

“It was once thought that the fish harvested in the Mediterranean and fish harvested in the Gulf of Mexico were from separate stocks,” she said. “However, in 1997, two TAG-program fish were caught in the Mediterranean while one was captured in the Gulf of Mexico. These are known spawning grounds. If fish from this area go to both spawning grounds, there is probably only one stock of fish.”

At this point, however, Block concedes that the answer is still unknown.

New tagging technology may help solve the riddle. For instance, fish tagged in 1997 were tagged with an old style of “archival” tag, which is implanted into the body cavity. The fish must be recaptured for the data to be recovered. To ensure that, TAG offers a $500 reward for the return of archival tags. Yet through January 2000, only 23 of 270 archival tags had been recovered. The new pop-off tags, on the other hand, release at a preset time and transmit their information from any ocean in the world for 10 days after release, making each tag useful.

Regardless of their differences, both methods are marvels of tracking technology. Archival tags contain sophisticated internal computers with a clock and a light sensor. These record sunset and sunrise information, which in turn allows researchers to calculate the fish’s daily latitude and longitude. The tags also have sensors to record how deep the fish swims, it’s body temperature and that of the surrounding water.

To date, information gained by archival tags indicates that, although giant bluefin tuna can swim at depths to 2,400 feet, they spend most of their time above 600 feet and considerable time at the surface. The fish are tolerant of water temperatures as cool as 40 degrees Fahrenheit. Yet, amazingly, their body temperature remains a near-constant 80 degrees. One archival tag has been recovered with 3.7 years of data and one with 2.75 years of data. These two tags alone have advanced scientific knowledge of these fish enormously.

While the new pop-off tags transmit the same type of information, the fact that they are released from the fish at a predetermined time tells where the fish are located at the time of release. The 1999-2000 pop-off tags were set to release in April, May and June, when tuna are likely to be spawning, perhaps in the Gulf of Mexico. For this reason, researchers tagged adult fish of 10 years or older with op-off tags. Smaller fish, which reveal less about the range of the breeding population, were still implanted with archival tags.
 Another difference is that pop-off tags are attached externally by impaling a dart beneath the skin. The tag’s onboard computer is preset to send an electric current through the attaching wire, which essentially melts the wire so the tag will float to the surface. At that point, for the next 10 days, the tag transmits via satellite all of the data it has gathered.

“We tagged captive tuna at the Monterey Bay Aquarium and watched the release of pop-off tags in the tanks,” Block said. “They deployed precisely at preset times. It is really amazing to see how they work.”

As of January 2000, data sent by 61 of 63 pop-off tags had been recovered. This is an astounding 95 percent recovery rate and the goal of the program is to tag a total of 1,000 fish with both types of tags by 2003.

Scientists aboard the Calcutta had tagged and released Bob Walmsley’s fish in less than two minutes. Not long after the hand shaking was over in the cockpit of the Wave Runner, a reel shrieked again. This time it was Don’s turn in the chair.

Three years younger than Bob and with a heavier build, Don made short work of his fish. Yet he was still sweating in the icy air when the Calcutta once again came astern to tag another “volunteer.”

By day’s end, the two brothers had caught the only giants tagged, despite dozens of other boats making the attempt in extremely rough conditions. Bob and Don celebrated with a high-five.

It had been a long journey from 1950, when two boys first rode aboard a rocking boat in the frigid North Atlantic, aiding their father in a three-hour battle with a 575-pound giant bluefin.

“The fish was o big we couldn’t get it into the boat, Don said. “We fought off sharks to save it on the way back to shore because it had to be tied to the side of the boat to haul it in.”

I took the brothers 50 years to close the circle begun by their father. While he kept his fish that long-ago day, his sons now released theirs with hopes of perpetuating giant bluefin tuna for the future of the species and for the enjoyment of their own children.

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