by Carl Safina
The seal lab has a microscope, a centrifuge, racks of test tubes, a sink, workbenches, a small seal skeleton, and a couple of lobster shells and various bird feathers for decoration. Even in the lab, the scientists work in bathing suits and bare feet. While Melissa and the others are preparing and storing the morning’s samples, she is explaining to me her spiritual perspective on her work as a wild-animal veterinarian. “I believe everyone has inside of them an innate sense of animals as beings. You see it most in children. As we go on in our lives, it gets covered over more and more. Most people have forgotten.” Melissa sees the basic nature of animal life as eating, sleeping, mating, and defending. These same things are basic for people, too, she says. “So, while in some ways we are different from other animals, the essence of what we are is the same. Since the great majority of the problems animals are facing are the consequences of human actions, I feel it’s our responsibility to be caretakers, to correct these actions, and be more gentle.”
A short while later, Melissa decides to take a break, saying, “Today I think we’ll actually have time for lunch.”
As we rummage through kitchen leftovers, Mary is telling Melissa and me about her studies of Northern Fur Seal pups. Mary says, “Young Fur Seals transform from little puppies, shivering in the rain like ordinary land animals, to fully adapted marine mammals capable of spending nine entire months in a frigid ocean. Very young pups can’t maintain their body temperature in water. They can’t stay warm. After they molt into their dense fur, their body temperature gets perfectly stable. Their metabolic rate gets stable too, even in the water. In other words, they can stay warm in really cold water without burning any more food to do it. That’s incredible when you look at the sea temperatures. A suite of things develop: the dense fur, the thick fat; their red-blood-cell density doubles—. So they really transform from tiny baby land mammals to truly aquatic marine-adapted animals. It’s truly amazing. By the first time they are ready to go to sea they don’t need to increase their metabolism to stay warm.”
“What’s the significance of the red-cell doubling—that they can carry more oxygen?”
“Exactly, so they can hold their breath long enough for deep diving. A whole bunch of physiological things prepare these guys for the first day they take to the sea.” She pauses for a far-off moment. “Working in the Pribilof Islands was fantastic. There were twenty thousand pups born at my study site. It was really incredible to see the abundance of animals there. Like here; same thing.” She adds, “I think people have some kind of need for animals and natural places. Just look where people pay the most money to go—Africa to see the wildlife, or coral reefs to snorkel. People spend a lot of money to see and experience the kinds of places that we would consider worth preserving. Where there hasn’t been any conservation, those places tend to be very unpleasant to live in or visit.” Mary used to teach at the Orange County Marine Institute, and she offers this possibility: “We had kids coming in from Los Angeles who live within fifteen miles of the ocean and had never seen a starfish. These were troubled kids. While I wouldn’t say that not seeing starfish was responsible for the situation they were in, I think it’s possible that the lack of open spaces and nature-type experiences contributes to a sense of disconnection, and discontent.”
MITCH AND MELISSA HAVE BEEN WORKING with Mary and Jason for just a few days, and they’re still getting to know one another. When Melissa asks Jason his age (he’s thirty-five), Mitch says, “Let’s not talk about age.” Rock-star looks notwithstanding, he’s closing in on an uneasy forty.
Melissa consoles him: “There was a man who lived to one hundred and twenty-nine. He said his secret was that he never told anyone his age.”
“Then how do you know how old he was?” Mitch says. “It’s all genetic anyway. You’re just destined to get what you get regardless of whether you smoke or are fat or don’t exercise.”
Jason says, “If it’s inherited, I’m destined for either heart disease, cancer, or senile dementia.”
“I’d try for the heart disease,” opines Mitch. As for him, now that he’s ripened toward forty he’s given this some thought. He wants to go by swimming here in June; he wants his last impression of the world to be a sudden jolt from a big shark.
Melissa says she doesn’t think so. “I watched two Galapagos Sharks kill a seal pup at Trig Island.” That’s just across the channel from Tern. “They took both her rear flippers and a front flipper. When the pup got to shore, you could see the shock in its eyes.” One shark dragged it back and they devoured it. “Not the way I’d want to go.” She shivers at the thought.
The misnamed Galápagos Shark lives in warm seas around the world’s midsection, showing a particular fondness for oceanic islands. Mitch remarks to me, “In the last year, more Galápagos Sharks have been preying on pups around Trig island. I’ve never seen that before. It’s always been, if anything, Tiger Sharks.” This year the sharks are a real problem for seal pups.
But overall, shark predation is not the root cause of trouble for the Hawaiian Monk Seal. The real threats to their numbers—the things that have landed them on the endangered-species roster—were killing by people in the early years and chronic disturbance by military personnel and their dogs in the latter half of the twentieth century.
Only about thirteen hundred Hawaiian Monk Seals grace the face of Earth at this point in human and planetary history. It’s an unlucky number times a hundred. That includes juveniles and the year’s pups. That’s it. Fifteen million years ago, and for every era, epoch, millennium, and century since, there have been more of them—until the last few decades. Before the Polynesians arrived, the main Hawaiian Islands might have served Monk Seals as breeding areas. Remember, there were no predators on land anywhere in Hawaii—any beach was an absolute safe haven. If the seals had been using the main islands, the Polynesians likely ate most of them and frightened away the rest. Virtually all remaining Hawaiian Monk Seals owe their existence to only six breeding populations in the Northwestern Hawaiian Islands.
But these islands didn’t always offer refuge. In the late 1800s, sealers, crews of wrecked vessels, and various fortune hunters nearly snuffed out the Hawaiian Monk Seal. In 1859 one ship took fifteen hundred Monk Seal skins, more than exist today. By the year 1900, seals were missing or nearly gone on several islands. After decades of slow increase, the population halved between the 1950s and the 1970s as military people and their dogs constantly scared females from breeding on the islands.
Now the Hawaiian Monk Seal is one of the most endangered mammals in the world. Now the idea is E ho’olaulima makou I malama ‘ilio o ke kai—“We must cooperate to take care of our Monk Seals.” Endangered means there is still time.
NO ONE KNOWS how many Hawaiian Monk Seals existed before humans first arrived in these islands, but since scientists made the first counts about fifty years ago, their tribe has declined by more than half.
They should consider themselves lucky. Their cousin the Caribbean Monk Seal (noted in 1494 by Christopher Columbus) inhabited a wide and lovely island-and-reef region from Mexico’s Yucatán Peninsula through the Bahamas. Europeans went on their usual spree, killing the fatally tame seals wherever they found them. Humanity finally deprived itself of the Caribbean Monk Seal in 1952, when the last handful vanished from Earth. And the Mediterranean Monk Seal now has a sword dangling over its big brown eyes, too; about four hundred exist, in tiny, widely scattered groups. So, holding at an all-time low for the last few years, the Hawaiian Monk Seal is doing the best of a beleaguered lot. And there might be a brighter future just over the horizon.
Virtually the entire historic decline of the Hawaiian Monk Seal was due to disturbance on land. Tern Island’s lowest counts coincided with a period of continual harassment by Coast Guard dogs. Disturbance made females move after giving birth, causing pups to get lost or prematurely weaned. Or, rather than pupping on larger islands, badgered females gave birth on sandbars so tiny and low they got washed over while the p
up was critically young.
In the late 1980s, humans dealt Hawaiian Monk Seals a new challenge: disturbance at sea. Mitch explains, “That’s when long-liners began fishing in Hawaiian waters for Swordfish and tunas.” In the late 1980s, over a hundred longline boats, fresh from having depleted Swordfish in the Atlantic, flocked to Hawaii. “They started hooking seals on their longlines. Several seals showed up here with hooks in them. Some had head injuries from being clubbed by fishermen.” With unusual haste, federal fishery managers created a fifty-mile no-long-lining zone around the breeding islands. This left the seals with two other issues related to fishing: likely competition with commercial fishing boats for lobsters and octopuses, and entanglement in lost nets. The severity of food competition is uncertain, but nets are a definite problem.
Mitch explains that in the last fifteen years or so, over 150 seals have been found entangled in derelict fishnets throughout the Northwestern Hawaiian Islands. Only about half a dozen were dead when found; the rest were tangled and still alive. That means either most tangled seals die and the carcasses disappear, or many tangled seals can get free. No one knows what percentage of tangled seals get free. But the carcasses of seals that die in nets must quickly get eaten by sharks, leaving no trace. The lost nets also tangle many sharks, fishes, and sea turtles.
Seals—especially young ones—also approach floating junk with the inquisitiveness that has always helped them learn how to survive. Now their intelligent curiosity risks entanglement and death. Because of the way the currents gyre around the Hawaiian Islands, derelict, lost, and dumped netting, as well as other fishing gear and debris, can arrive here from just about any country in the North Pacific. Lots of the netting on these islands has drifted in from over a thousand miles distant, off Alaska and Asia. It causes trouble to several kinds of seals, whales, and turtles here, there, and along the way. In the late 1990s, federal researchers found an average density of 230 pieces of lost and discarded netting per square mile at French Frigate Shoals, and estimated that 38,000 net fragments burdened the Shoals. In fact, there’s a large pile of derelict netting beside the runway here. I’ve sat comfortably on that immense pile of netting, contemplating the discomfort it caused to creatures less fortunate. None of it is local in origin; nets like that aren’t used around here. But all of it was pulled from the waters and reefs of French Frigate Shoals by the people who work here.
So now, finally, Monk Seals might just possibly be entering an era where, on balance, humans are helping more than hurting them. At least, humans are basically leaving the seals alone, not constantly disturbing them. In fact, in the central part of the chain, places like Laysan and Lisianski Islands, the seals are holding steady. And Monk Seal numbers are actually climbing in the northwestern end of the chain—places like Midway and Kure Atolls—where numbers had dropped by as much as go percent.
But in the more southeasterly locations, most notably here at French Frigate Shoals, survival has been terrible for more than a decade. This is a troubled population. The many pups produced here—about seventy births per year—just aren’t surviving well after weaning. It wasn’t always that way. Back in the late 1980S, survival of first-year pups was something like 70 to 80 percent. For older animals, annual survival was commonly 90 percent.
In 1990 pup production fell here—nearly halved—and first-year survival rates began plummeting. By the late 1990s, first-year survival rates had dropped to well under 30 percent. Since 1900 the number of Monk Seals surviving to reproductive maturity has declined to about a tenth of what it was in the 1980s. From the class of 1990, for example, only three animals survived to breed.
French Frigate Shoals still has the biggest population of Monk Seals in this island chain. But the seal population in this atoll has fallen from eight hundred during the late 1980s to about four hundred right now.
Mitch emphasizes the point: “At the rate that we’re losing pups in French Frigate Shoals, there won’t be enough young animals to maintain the population. Even though we’re actually seeing increasing numbers at the northwest end of the island chain at the moment, the problem at French Frigate Shoals has been so dramatic, it’s pulling down the total population.” Though French Frigate Shoals is still producing about half of all births, 65 percent of those pups are dead within a few months.
Shark predation, adult male aggression, disease, parasites, ciguatera poisoning, entanglement, and even human disturbance have been ruled out as primary causes of the most recent French Frigate decline. The new sampling will soon rule out morbilliviruses entirely.
“What’s the speculation about what’s going on?” I ask.
“Well, the speculation is—” Mitch hesitates. “That they’re starving here, mostly. When survival started dropping, you would see animals not doing so well, looking like they might be starving. Then you started seeing them starving earlier in the season. Now, you don’t see them starving—they just disappear.”
But it’s not one factor alone; it’s a suite of all the problems, pulling in the same downward direction.
Hawaiian Monk Seals contend with yet another predicament: some islands have developed skewed sex ratios, probably a chance artifact of their populations having been driven to very low levels. At islands with more females than males—Midway Atoll, Kure Atoll, and Pearl and Hermes Reef—seals are increasing. But at islands with more males than females, mobs of males have killed females and juveniles in mating attempts. This results in even fewer females, making the problem worse and worse. (At Laysan during the early 1990S, males outnumbered females by two to one, and as many as ten females per year died as a result. Researchers have on several occasions effectively dealt with this by removing males to bachelor exile on other islands, away from breeding colonies. In 1994 they removed twenty-two males from Laysan.)
Mitch sums up by emphasizing the magnitude of recent problems. “So, between starvation, predation, entanglement, and killing by certain problem males, about sixty pups disappeared from this atoll in just the last two years. At that rate, the chances of any surviving long enough to breed …”
“That’s very sad.”
“Very. Actually—it’s bizarre.”
AFTER LUNCH THE SEAL TEAM goes off to sample more seals on other islands in the Shoals, returning in the late afternoon to the lab.
In the early evening, while the others eat dinner at the far end of the building, the seal team spends two hours sorting, stabilizing, preserving, and analyzing blood and biopsy samples. They check blood glucose levels. They make slides of blood samples for microscopic analysis. They freeze samples in liquid nitrogen for later transport and analysis. Melissa counts white blood cells to get a sense of whether a seal is fighting off an infection. Jason takes a centrifuge-spun capillary tube of blood and compares the fraction of the blood that is red cells—“packed red-cell volume”—against a printed scale. This is to determine hematocrit level, which is an indicator of hydration and anemia. Mary looks at blood urea nitrogen (Melissa says, “We call it BUN, for fun”) by testing a drop of blood on a reactive litmus-like strip; this gives her information about protein metabolism and kidney function.
Jason says, “Basically, what we’re doing here is keeping track of stuff.” The team is spinning most of the blood and the plasma, parceling it into tubes, and packing it in liquid nitrogen. Jason explains, “If somebody needs some serum for screening at a later date, we don’t have to thaw blood; we just pull out one little tube.” The blubber gets frozen for further analysis, and bacteria samples will be placed into a culturing medium.
Mitch, wearing a T-shirt that says LOVE MAKES THE WORLD ONE, explains that here at French Frigate Shoals the seals seem to mature at later ages and stop growing at smaller sizes than elsewhere. This may be further evidence of the suspected food scarcity. Melissa says, “New ways of analyzing fatty acids in the blubber can identify parts of their diet. It may show us, for instance, whether juvenile seals rely on lobsters. If so, competition with commercial lobster fishing m
ay underlie their nutrition problems—or maybe we’ll find their food problems really have very little to do with commercial fishing.”
The question of whether fishing robs Monk Seals of significant food has been hotly debated for years. Fishery managers long ignored the Marine Mammal Commission’s repeated pleas that waters within twenty miles of French Frigate be closed to lobstering. The fisheries people wanted proof that commercial fishing for lobsters and octopuses would hurt seals—and the mammal people wanted proof the fishing wouldn’t. Who should bear responsibility for the burden of proof? That fight was philosophical, but critically endangered seals were starving.
The mammal commission’s director, John Twiss, in what he later referred to as “a series of extraordinarily unrewarding exchanges,” pressed fishery managers throughout the 1990s to close the area around French Frigate Shoals to lobster fishing. In one letter he wrote, “The best available information clearly indicates that monk seals at French Frigate Shoals are food-stressed and that lack of food is causing the death of newly weaned pups. It is also clear that monk seals eat lobsters and octopi, … that commercial lobster fishermen take both lobsters and octopi, that commercial lobster fishing has occurred at French Frigate Shoals and neighboring banks, and that declines in monk seals at French Frigate Shoals occurred concurrent with declines in abundance of exploitable lobsters.” The following year, Twiss felt compelled to write, “The current status of the population is critical … due almost entirely to an alarming decrease at French Frigate Shoals.” One year later he again wrote to then head of the fisheries service: “The National Marine Fisheries Service is not adopting a prudent, precautionary approach to the management of lobster fishing at French Frigate Shoals … . Steps must be taken to prevent lobster fishing at that atoll.” No steps were taken. So in 2000, the (Center for Biological Diversity, Turtle Island Restoration Network, Creenpeace Foundation, and Earthjustice Legal Defense Fund sued to end lobster fishing in then Northwestern Hawaiian Islands. Agreeing with the plaintiffs, a federal judge indefinitely closed the islands to lobster fishing, finding that the National Marine Fisheries Service has “failed to protect the endangered Hawaiian monk seal from the impact of the fishery.” So maybe there are fatter times ahead for French Frigate Shoals’ skinny seals.
