Can the Ocean’s Fastest Shark Outswim Our Appetite for It? Overfishing could be threatening shortfin makos, treasured by fishermen for their fight and their meat.
By Glenn Hodges August 2017 National Geographic Magazine
Zane Grey made his name writing adventure novels about the American West, but his real love wasn’t gunslinging or cowpoking; it was deep-sea fishing. He held 14 world records for catching saltwater fish, including the first billfish over 1,000 pounds landed with a rod and reel, a marlin he caught in Tahiti in 1930. But nothing compared to the shortfin makos he encountered off the coast of New Zealand in 1926. The first mako Grey got on the line was a 258-pounder, and when he reeled it to the side of the boat, “quickly I learned something about mako!” he wrote in his book Tales of the Angler’s Eldorado, New Zealand. “He put up a terrific battle, broke one gaff, soaked us through with water, and gave no end of trouble.” Once the shark was landed, Grey marveled at its build—streamlined, muscular, with a head like a bullet. “I had never seen its like,” he wrote. “Every line of this mako showed speed and power.” But it was the 1,200-pounder that the captain of his boat battled that led to almost mythical superlatives. After a long fight in which the mako “leapt prodigiously and made incredible runs,” the shark bit through the leader and escaped. “I was terrified,” the captain told Grey. “It seemed that mako filled the whole sky. He was the most savage and powerful brute I ever saw, let alone had on a line!”
Almost a century later, shortfin makos still have a herculean reputation among fishermen, who love them for their fight and their meat in equal measure. But a century of fishing appears to have taken a toll. Shortfin makos — which are distinguished from their much rarer cousins, longfin makos, by, among other things, their shorter pectoral fins — are eagerly targeted by recreational fishermen and frequently caught as bycatch by commercial long-liners. Their meat rivals swordfish in quality, and their fins are prized in Asia for shark fin soup, a combination that has put makos under significant pressure. But how much pressure, and to what ultimate effect, is uncertain. Scientists have no clear idea how many makos there are in the Earth’s oceans, and most of the data on catch and mortality rates come from commercial fishing operations, which famously tend to underreport catches. So biologists studying makos are trying to fill in some huge knowledge gaps.
In the summer of 2015 I was invited to join a mako-tagging operation off the Maryland coast with scientists trying to bridge some of those gaps. I thought it would go like this: We catch big makos; they put on the kind of show that Zane Grey saw; and I get great coloUr for this story. Instead, I learned firsthand that Mark Twain was right about seasickness (“At first you are so sick you are afraid you will die, and then you are so sick you are afraid you won’t”) and was woozily indifferent when the fishermen on board reeled in two small makos, neither of which put up much of a fight. So I decided to try again—this time with a seasickness patch—in Rhode Island later in the summer. And that’s when I saw what I really needed to see.
On each trip I accompanied scientists affiliated with the Guy Harvey Research Institute, which has been tagging and tracking makos in the Atlantic Ocean and Gulf of Mexico since 2008, with the primary objective of studying the sharks’ movement patterns. Makos in the western North Atlantic are highly migratory, traveling northward during the warmer months and then south as winter approaches. The excursions off Maryland’s coast in May were a resounding success: Over two weeks, 12 makos were fitted with satellite transmitters. By contrast, the Rhode Island excursions in August were a resounding failure: one week, zero makos. But that contrast offered a clue as to what might be happening with makos in the Atlantic.
To pick up on the clue, you have to know one of the first things you learn when you’re fishing for makos: They share territory with blue sharks. The two species are kind of like lions and hyenas, coexisting in the same areas as they pursue different feeding strategies. Shortfin makos are the fastest sharks in the ocean, capable of reaching 35 miles an hour as they chase down speedy prey such as bluefish and tuna, and sport fishermen love their power. Blue sharks, on the other hand, are relatively laconic and focus on slower prey, like squid. Catching them is like, in one fisherman’s words, “reeling in a barn door,” and their meat is not nearly as good to eat as a mako’s. So you can guess which one is the lion in the analogy and which is the hyena. Everyone wants to bag the lion.
On our second day out of Narragansett, Rhode Island, as we hauled yet another blue shark to the side of the boat, I finally took note of the obvious. “It seems like all the blue sharks have hooks in their mouths,” I said. Brad Wetherbee, the marine ecologist from the University of Rhode Island who was there to tag any makos we caught, said, “Yup. Every one we’ve brought back to the boat so far has had a hook in it.”
Removing a hook from a shark’s mouth can be dangerous, so fishermen just cut the leaders and leave the hooks to rust away. And because the fishermen are after makos, they’re much more likely to release blue sharks. “I’ve never seen a mako with a hook,” the ship’s mate, Lucas Berg, told me our first day out. “People don’t ever let them go. But we’ve caught blue sharks with four hooks in their mouth.”
The fishing pressures on makos are intense, Wetherbee explained. The ones we were trying to catch swim northward up the Atlantic coast in the summer, and between everyday recreational fishing and the dozens of shark-fishing tournaments held between Maryland and Rhode Island, it’s a perilous journey for the sharks. “A lot of them have been weeded out by the time they get up here,” Wetherbee said. “Is the catch rate sustainable?” I asked him. Makos, like many sharks, are especially vulnerable to overfishing because of their small litters and high age of sexual maturity. (One study suggests that female makos don’t reach maturity until around 15 years old or later, but these figures are not definitive. Biologists agree more research is needed.) “We don’t know,” he said. “These are far-ranging, international sharks—some of our [tagged] makos have gone into the waters of at least 17 different countries—and there’s not enough data for management agencies to come up with a good estimate of whether the population is going up or down or staying the same. There’s probably some number of mako sharks that would be fine to catch and kill. But we don’t know if it’s 100, or 1,000, or 100,000.”
According to the National Marine Fisheries Service, which regulates fishing in U.S. waters, makos are being fished at a sustainable level. This assessment is based largely on catch figures supplied by commercial long-liners to the international organization that regulates fishing for tuna and other pelagic fish in the Atlantic, and those figures show a relatively consistent harvest over recent years, suggesting that mako populations are stable. But the figures are an imprecise measure. The catch is recorded in metric tons, and basic information like the number of sharks caught, and the size and sex of those sharks, can be missing. On top of that, many catches go unreported, leading scientists to question the reliability of both the data and the stock assessments.
What Wetherbee and his team do know is that the sharks they’re tagging are not faring well. The tags they use—about the size of a Zippo lighter, mounted on the dorsal fin—send signals to satellites every time the sharks surface, allowing researchers to create detailed maps of their movements. When the signals start coming from land, they know the sharks have been caught. “We’ve tagged 49 makos, and 11 have been killed,” Wetherbee told me. (Within a month, that number had increased to 12.) I said that seemed like a lot, and he agreed: The sample size is small, but the catch rate is troubling. Back on land, I called Mahmood Shivji, the Nova Southeastern University scientist who leads the tagging project. “What amazes me,” he said, “is that it’s a vast ocean out there and these animals move a lot, and yet these tagged animals are running into fishing hooks to the tune of 25 percent. No shark fishery can sustain a 25 percent removal every year.”
After my seasick cruise, I returned to the Maryland shore for Mako Mania, an annual shark-fishing tournament held at the Bahia Marina in Ocean City. This Mako Mania should not be confused with the Mako Mania tournament in Point Pleasant, New Jersey—or, for that matter, with the Mako Fever tournament in New Jersey or the Mako Rodeo tournament, also in New Jersey, or with any of the other 65 or so U.S. tournaments that include prizes for pelagic sharks like makos, threshers, and tiger sharks. After Jaws hit theatres in 1975, tournaments popped up along the eastern seaboard, and ever since, summer has not been a good time to be a shark in the North Atlantic.
I arrived at the marina just as the first sharks were being brought to the docks. It was a festive scene—hundreds of people eating and drinking and cheering for the anglers and their kills. Next to me a woman and a young boy watched as a 282-pound mako—the winner in the mako category, it turned out—was hoisted to be weighed. The anglers pulled up the snout for photographs, and the woman turned to the boy and said, “This is really cool, right?” The boy nodded silently, transfixed by the shark’s bloody grimace.
As the sharks continued rolling in—147-pound mako, 466-pound thresher, 500-pound thresher, 174-pound mako—I talked with the tournament’s organizer, Shawn Harman. “What’s more fun than seeing sharks?” he asked, surveying the cheering crowd. When we got to some of the knottier questions about the controversy over “kill tournaments,” as critics call them (versus “no kill” or “catch and release” tournaments, which are rare but do exist), he explained that his tournament was not like those of old—back in the 1970s and ’80s, when the sharks would pile up on the docks and go wholesale into the Dumpster afterward. Here, the only sharks brought to the dock were threshers and makos, the best tasting sharks in the ocean, with minimum sizes and a catch limit of one fish per boat per day. (Over the course of three days, 16 sharks were brought to the dock to be weighed.) “Nobody’s wantonly killing fish here. Everyone here eats what they kill.” I asked him where I might find mako on the menu, to see what it tastes like, and he fetched a fillet from one of the sharks just brought in, had it blackened, and served it to me on a bun with wasabi mayo. It was delicious—as good as any billfish I’d ever had.
But the tasty sandwich and the festivity of the scene could not entirely conceal the problematic nature of the event. Later in the day, one of the fishermen told me that a 500-pound thresher shark brought in earlier had been pregnant, and when it was gutted, the tournament staff tried to hide the pups from the crowd. Threshers, like makos, are considered “vulnerable” by the International Union for Conservation of Nature, and though killing the pregnant females of vulnerable species may be legal, it makes for bad publicity. I asked Harman about the pregnant shark. He denied the story, so I asked one of the guys cleaning the fish, and he said yes, there had been three or four pups, each two to three feet long. I went back to Harman to ask him why he denied it. He got a little flustered and told me he was afraid of being the “bad guy” in the story. “We’re following the law, according to what the law says is sustainable,” he said. “If they make it illegal, we’ll stop.”
The captains of the boats I went out in for those tagging operations in Maryland and Rhode Island are both longtime shark fishermen. They are not reflexively against the capture and killing of fish, and they are not squeamish about what deep-sea fishing entails. But both men have qualms about how sharks are being fished. Mark Sampson, the Maryland captain, started a prominent shark-fishing tournament in Ocean City in 1981 and ran it for more than three decades. But he became increasingly concerned about the conservation of shark populations, so he made his size limits more restrictive to reduce the number of sharks caught. He also insisted that anglers use “circle hooks,” which, in contrast to conventional “J-hooks,” don’t lodge in a shark’s stomach when swallowed and result in fewer unnecessary killings. Some fishermen balked, participation declined, and because of the higher size limits, he said, “we had days in our tournament where not a single shark was brought back to the dock. “That’s not the recipe for a successful tournament, because people want to see those fish being brought in and weighed,” Sampson said. He shuttered his tournament in 2014, and he doesn’t accept charters for anglers who want to use his boat to participate in other shark tournaments.
Charlie Donilon, the Rhode Island captain, has run shark-fishing charters since 1976. Where Sampson is quiet and circumspect, Donilon is talkative and emotional, and on one of those days in August when we were on the boat waiting for the fish to bite, he told me about the time a client reeled in a mako that refused to go gently. “I threw a harpoon in it, then I hit it with a flying gaff, and then tied it down to a side cleat, and the thing is scratching and blasting blood everywhere, and it’s all being recorded by the client. The guy sent me the video, and I watched it with my wife, and she asked, ‘Does that bother you?’” It did, he said, and he started trying to persuade his customers to release the sharks they caught. “I’d tell people, a 100-pound mako is just a tot, just a kid, because they have the potential to grow to 1,000 pounds or more. So I’d really like to let it go, because it’s an immature fish.” But since almost all the makos they catch out there are juveniles, it stopped making sense to even ask the anglers. So in 2015 Donilon instituted a catch-and-release policy, no exceptions. His business has taken a hit. “I’m way off what I used to be,” he said.
I thought of all the blue sharks we’d seen with hooks in their mouths, and it seemed to me he was right: pretty slim. Although most of the tagging study’s casualties had been killed by commercial fishermen in international waters—not by recreational fishermen—the Fisheries Service’s statistics attribute the majority of the mako kills in the U.S. to recreational fishermen. So who is fishing too much, and where? Empirically, it’s still too soon to say. But Donilon, at least, doesn’t need to wait for more data to render his verdict.
“I did my share of killing,” he said one afternoon on the boat. “You know how there might be a guy in Africa who used to be a poacher, and he used to kill all the lions …” And as he said this, his eyes teared up and his voice started quivering, and finally he choked out a half whisper: “You’ve got to give back. We just take, take all the time …”
Ultimate Hunter
“Torpedoes with teeth.” That’s how photographer Brian Skerry describes shortfin makos. “That conical nose just pierces through the ocean.” Though mature females can exceed 1,300 pounds, the sharks remain fast enough to ambush speedy tuna.
Though not as big as great whites or tiger sharks, shortfin makos are among the most versatile marine predators, built to race and range. Able to hit 35 miles an hour while chasing prey, they’re the fastest sharks over short distances. Because they can maintain the temperature of key body parts, they venture into depths and latitudes too cold for most other shark species.
Like all sharks, makos have teeth optimized for their prey. Needlelike teeth allow them to grab and hold some of the ocean’s fastest targets—tuna, swordfish, and other sharks.
Actual size: Max. length: 13 feet. Max. weight: 1,300 pounds
Maximum annual mako migration distance: 2,485 miles
Maximum daily distance traveled by juvenile makos: 62 miles
Shortfin makos are highly migratory sharks, usually preferring waters within 500 feet of the surface.
Superior Swimmer – the fastest shark
Top speed (miles an hour): Michael Phelps 4.3, Atlantic bluefin tuna 25, Great white 30, Shortfin mako 35 (top swimming speeds are approximations. No reliable maximums have been recorded in the wild)
Average cruising speed: Shortfin mako 4.2, Great white 5.0, Blue 1, Yellowfin tuna 2.8
What makes mako sharks the fastest sharks in the ocean? Shortfin makos are considered the fastest sharks over short distances, superior even to great whites when it comes to quick bursts of speed. Makos hold a substantial edge over its competition when it comes to physiology.
Endothermic. Mako can maintain warmth in some body parts. The energy efficiency gives them multiple advantages such as improved swimming performance. Three heat exchange systems allow the mako to retain heat in the red muscle, liver and digestive organs and the eyes and the brain producing higher temperatures than that of surrounding water. Heat is transferred between cold and warm blood vessels. All sharks lose heat in their gills, but the mako’s unique arrangement of veins and arteries allows transfer of heat between warm and cold blood, trapping heat around viscera and red muscle and pumping warm blood to the brain.
Stronger Tail. The mako’s caudal keel – a ridge on the back – is flat, which supports the fins and decreases drag as the tail moves side to side.
Smoother Stroke. Centrally placed red muscle connects only at the mako’s tail, creating a smooth, efficient power stroke. A blue shark’s red muscle connects to other muscles and the skin, resulting in a less streamlined pattern.
Larger Appetite. The mako’s warmer body temperature expands its range, but its faster metabolism increases the amount of food it needs.
Greater Stamina. Like distance runners, sharks rely on red muscle, made of slow twitch fibres to power their emigrations. In makos, red muscle creates heat and more proteins that boost oxygen flow.
Quicker Acceleration. White muscle, made of fast twitch fibres, acts swift acceleration. The mako’s white muscle quickly takes in oxygen, allowing it to recover rapidly for more frequent sprints.
Better Breathing. The large suface area of the mako’s extensive gills helps it efficiently absorb oxygen, which is then distributed through the blood. Its large heart pumps more blood. Gill surface area 56.5 sq. ft.
Blue Shark. Ectothermic – Cold-blooded blue sharks can dive deep, but their cold bodies move slower and can’t stay as long at depth. Proportion of body weigh consumed daily 1%. Muscle recovery half as fast. Gill surface area 19.5 sq. ft
Images
A diver keeps close tabs on a juvenile mako off the coast of San Diego, in an area where the sharks are known to give birth. Mature females bear as few as four young every three years.
A mako prowls near a drifting clump of kelp off the San Diego coast. Such patches of floating kelp anchor miniature ecosystems, with larger fish preying on smaller fish and makos at the top of the food chain.
This juvenile mako “came in hot,” says Skerry, and destroyed part of his camera’s housing. Though makos rarely attack humans, the human threat to the sharks is substantial. In 2007 they were classified as vulnerable because of overfishing.
Three sharks is a crowd for makos, which tend to be solitary and highly migratory, sometimes crossing the waters of more than a dozen countries. One shark tagged near New Zealand, where mako populations are robust, traveled 11,600 miles in a year.
A young mako lies gutted on the dock of Star Island Marina in Montauk, New York, site of an annual shark-fishing tournament. More than 60 tournaments, targeting shortfin makos, threshers, and tiger sharks, are held along the eastern seaboard each summer.
Parasitic copepods cling to the fin of a shortfin mako. They feed on different parts of the shark’s body, eating everything from mucus and blood to upper layers of skin.
Donilon accepts the loss of business because it doesn’t seem to him that the fishing is sustainable, no matter what the government says. “The sharks we tag, there’s like a gantlet they have to go through coming up the coast. They’ve got to go through Maryland, New Jersey, Long Island, Massachusetts—and everyone in the world is out there fishing,” he said. “They’ve got to be at least 15 years old in order to reproduce, the females. Now what are the odds of that shark making it up here 15 times without being caught? Pretty slim.”