It is, if you will, a classic catch-22: Those of us who want to protect the eel in order to preserve something genuinely mysterious and enigmatic in a world of enlightenment will, in some ways, lose no matter how things turn out. Anyone who feels an eel should be allowed to remain an eel can no longer afford the luxury of also letting it remain a mystery.
At least we know one thing about the demise of the eel: it’s our fault. All the explanations put forward by science to date have something to do with human activity. The closer humanity gets to the eel, and the more it’s exposed to the influence of our modern living, the faster it dies. When the International Council for the Exploration of the Sea (ICES) summarized what should be done to save the eel in 2017, it was simultaneously vague and laudably clear: the impact of human activity on the eel should be “as close to zero as possible.” We still don’t know everything about the threat to the eel, but what we do know is enough to identify the only way of saving it: we have to leave it be.
What we know, for example, is that the eel is struggling with disease, and more so now than before. It’s susceptible to, among other things, the herpes virus anguillae, a disease first discovered among Japanese eels in captivity, which has since spread through imports to wild eels in Europe. The first Dutch case was identified in 1996; in southern Germany, tests have shown that nearly half of all eels have it.
For some reason, the virus seems to affect only eels—hence its name—and it’s an unusually unpleasant disease. The virus can lie dormant in its host for a long time, but once it breaks out, it has a quick and aggressive course. The eel develops bleeding sores around its gills and fins. The cells in the gills die and the blood-filled filaments stick together. Its inner organs become inflamed, rendering the eel tired and lethargic until it can move only slowly and near the surface, until its body finally gives up and it dies.
Eels can also catch the parasite Anguillicoloides crassus, a nematode. It, too, was first discovered among Japanese eels and reached Europe in the 1980s, probably piggybacking on live eels imported from Taiwan. In just a few decades, it has since spread across all of Europe and to America. A 2013 study in South Carolina showed that as early as the glass eel stage, 30 percent of eels carried the parasite. The study also indicated the parasite had spread faster due to well-intentioned attempts to save the eel by releasing caught glass eels in new waters.
The nematode is a kind of roundworm that specifically attacks the eel’s swimming bladder, causing bleeding, inflammation, and scarification. An infested eel grows more slowly and becomes more susceptible to disease. It moves into shallower waters and can swim only for short distances. The parasite isn’t necessarily fatal, but an eel infested with Anguillicoloides crassus has very poor prospects of reaching the Sargasso Sea.
What we also know is that the eel is particularly sensitive to pollution. Since it lives for a long time and sits high up the food chain, it’s particularly affected by industrial and agricultural toxins. And as with the parasites, the toxins seem to impede the eel’s ability to make the journey back to the Sargasso Sea. Eels exposed to PCB, for example, have been shown to develop heart defects and edema and problems storing fat and energy, which makes the long migration virtually impossible. Eels exposed to various pesticides have been shown to be less able to transition from fresh to saltwater. And if appearances are anything to go by, if it’s true that fewer silver eels reach their spawning grounds, pollution is at least a likely contributing factor.
Some theories are harder to prove. There are some signs pointing to the eel’s falling prey to other predators more often than before, which may not be directly attributable to humans; but it’s conceivable that eels that are sick, weakened by toxins and parasites and therefore moving more slowly and closer to the surface, also make easier targets for predators like cormorants, who are plentiful and love feasting on eels.
Some modern threats that researchers consider the most serious, and which are unquestionably caused by humans, are the various physical impediments to the eel’s migrations. Locks, sluices, and other artificial means of water regulation can keep young eels from swimming up waterways and mature eels from reaching the sea. And hydroelectric plants, beneficial as they may be for the greater environment, are death to eels. The dams’ turbines kill scores of silver eels on their way toward the Atlantic, with some reports claiming that each power plant kills close to 70 percent of all eels trying to pass through. The fish ladders built to circumvent the dams are, by and large, customized for use by the more shallowly inclined salmon.
One old threat to the eel’s survival is, of course, fishing, though the severity of its impact has long been the subject of debate. Historically, the eel has been a popular food in many parts of Europe; not only have eel fishermen had their own traditions, tools, and methods, the eel industry has also supported a distinct and in places significant economy. Over the past few decades, exports to Japan—which is now responsible for 70 percent of the world’s eel consumption and which, like Europe and America, is feeling the effects of a shrinking eel population—have risen dramatically.
Particularly devastating to the eel’s complex life cycle has been the fishing for glass eels. These days, this is primarily done in Spain and France—in the Basque Country, glass eels fried in oil and garlic have become an increasingly expensive delicacy in recent decades—and since they are caught in such large numbers, and at such an early stage of life, the fishing has an outsize impact on the greater population.
A threat that’s more difficult to illustrate, but which may nevertheless be the most serious, is climate change. It’s an indisputable fact that when the climate changes, both the direction and the strength of the great ocean currents change, which seems to be impeding the eel’s migration significantly. Altered currents can make it more difficult for the silver eels to get across the Atlantic and find the right spawning ground. More important, however, is the effect this has on the newly hatched larvae that helplessly drift along the currents to Europe.
When the currents weaken and change course, it likely also affects the location of the spawning grounds within the Sargasso Sea, which means the weightless, transparent larvae may fail to find the current that is supposed to carry them to Europe, or that they are simply carried in the wrong direction. Moreover, climate change can alter the currents’ temperature and salinity, which in turn affects the production of plankton on which the larvae feed during their journey.
Several studies point to climate change as a major contributing factor in depressing the number of glass eels reaching the coasts in recent years. It is, if nothing else, an ominous warning signal. It means, after all, that the extremely complicated and sensitive process that is the eel’s migration and reproduction, which has functioned for millions of years, has now, in just a few short decades, been fundamentally hobbled.
SO WHAT WILL REMAIN OF THE EEL IF IT GOES EXTINCT? PICTURES, memories, and stories, of course. A riddle that was never fully solved.
Perhaps the eel will become the new dodo. Perhaps it will seem less and less like a real, living creature and more and more like a tragicomic, symbolic reminder of what humankind is capable of in its most oblivious moments.
The dodo was a clumsy, broad-beaked bird that humans first came across at the end of the sixteenth century and had hunted to extinction less than one hundred years later. It was discovered and described for the first time by Dutch sailors on the island in the Indian Ocean that would later be named Mauritius, the only place in the world it ever lived, as far as we know.
It was a large bird, about three feet tall and weighing more than thirty pounds. It had tiny wings, grayish-brown feathers, a bald head with a slightly bent, green-and-black beak. Its legs were yellow and powerful, its rump rounded and wide. It was flightless and moved fairly slowly, but had no natural enemies on the island before humans arrived. Contemporary depictions often ridiculed its appearance, almost caricaturing it; its expressionless eyes like tiny round buttons in its big, bald h
ead, a look of surprise and dim-wittedness on its face.
The earliest mention of the dodo in writing, in a report from a Dutch expedition in 1598, describes it as a bird twice the size of a swan but with the wings of a pigeon. It was also said that it didn’t taste particularly good and that its meat was tough no matter how long you cooked it, but that the belly and breast were at least edible.
Which is of course what the Dutch sailors did to the dodo: they ate it. It was very easy to catch, after all. It’s said the birds didn’t even try to escape when the sailors approached them. They were fat and rich in meat; three or four of them was enough to feed a whole crew. Dodoes were described as nonchalant and unperturbed, as though utterly unable to imagine that another creature could potentially constitute a threat. A drawing from 1648 shows sailors merrily beating the clumsy birds to death with big sticks. Their fate was not only to be the dinner of hungry Dutch sailors, however; humans also brought other invasive species to the island: dogs, pigs, and rats that competed for space and food and raided the dodoes’ nests, eating their eggs and chicks.
In the summer of 1681, Benjamin Harry, a sailor, mentioned in his diary that he had seen a dodo in Mauritius. That represents the last documented sighting of a living specimen. The dodo he saw was, if the story is to be believed, the very last one. Then it was dead, extinct, and all that remained were fading memories.
For a while, the dodo was forgotten or depicted as a vaguely mythological creature, rather than a real animal. Some doubted it had ever existed at all. When Alexander Melville and Hugh Strickland published their book The Dodo and Its Kindred, the most exhaustive description of the dodo at the time, in 1848, they were forced to admit that information about this bird, which had been extinct for more than 160 years, was scarce, to say the least. “We possess only the rude descriptions of unscientific voyagers, three or four oil paintings, and a few scattered osseous fragments, which have survived the neglect of two hundred years. The paleontologist has, in many cases, far better data for determining the zoological characters of a species perished myriads of years ago, than those presented by a group of birds, several species of which were living in the realm of Charles the First.”
They were at least able to establish that the closest living relative of the dodo is the pigeon; modern DNA testing has since confirmed their findings. Other than that, though, Melville and Strickland didn’t contribute much to our overall understanding of the dodo. That this idiosyncratic creature lived where it lived and only there was not at all strange, they argued. The temporal and geographical distribution of species had nothing to do with environment or climate, and certainly not with evolution. It was the “Creator’s” way of preserving “the ever vacillating balance of Nature.” That the dodo had become extinct was, consequently, not surprising. “Death,” they wrote, “is a Law of Nature in the Species as well as in the Individual.”
In time, however, we would learn a lot more about the dodo. In 1865, the first fossil was found, and science began to take a greater interest in its unique fate, both as the odd bird it had been and as an example of humankind’s boundless and irrevocable impact on all life on this planet. Since the end of the nineteenth century, countless books have been written about the dodo. Lewis Carroll’s Alice’s Adventures in Wonderland has made it iconic; it is doubtless one of the most widely recognized extinct species today. Furthermore, the dodo has become a symbolic creature, not only as a cautionary example of the reckless cynicism of humankind, but also as a metaphor for something outdated and obsolete. A dodo is a person who is stupid and clumsy and incapable of adapting to a new era, someone who has been rejected and forgotten, become irrelevant.
“Dead as a dodo,” as the expression goes. It may be that we will eventually say “dead as an eel” instead.
THAT MAY BE PREFERABLE TO OTHER CONCEIVABLE FATES. PERHAPS the eel will instead become something like Steller’s sea cow, a quickly fading memory of something odd and unfamiliar.
Steller’s sea cow was the name of a marine sirenian first described in the middle of the eighteenth century by the German scientist Georg Wilhelm Steller. It was a gigantic mammal, a languid, slow herbivore like its closest relatives, the dugong and the manatee. It had thick, bark-like skin and an undersize head relative to its enormous body, two small arms in front, and a whalelike tail in the back.
Georg Wilhelm Steller first spotted the animal during an expedition led by the Danish-Russian explorer Vitus Bering, in what would eventually be named the Bering Sea. It was Bering’s second expedition to the mostly unexplored region, and his mission, given to him by the Russian navy, was to sail across the sea and map the west coast of North America. Steller had on his own initiative, driven by curiosity and a thirst for adventure, traveled east through Russia to join Bering. He’d studied theology, botany, and medicine at the University of Wittenberg, accompanied a caravan of wounded Russian soldiers to Saint Petersburg, and secured a position as the personal physician to the archbishop of Novgorod. He was almost thirty and just married when he set off through vast Siberia in the winter of 1737, with his sights set on the Kamchatka Peninsula, where Vitus Bering was preparing for his expedition.
On May 29, 1741, the ship Saint Peter set off from Okhotsk with a crew of seventy-seven. It would be a disastrous journey in most respects. Almost immediately, the expedition encountered difficult weather, lost contact with its sister ship, the Saint Paul, and was forced to veer south across the sound toward the North American coast. Once they reached Alaska, the crew was already in poor shape, and many were suffering from scurvy. On top of everything else, Bering and Steller didn’t get along. Bering wanted to hurry up and map as much of the coast as they could and then turn back before the arrival of the autumn storms. Steller, for his part, wanted to do what he had come there to do: study the flora and fauna.
After about two months at sea, Bering developed scurvy, and it was decided the ship would immediately turn around and return to Kamchatka. But a violent storm intercepted them, and the ship ran aground on the reefs off an island that no one knew existed. There, in the breakers off the strange land, while most of the crew were lying unconscious in the damaged ship and the corpses of the already perished were being thrown overboard, an eager Steller immediately started planning his excursions. He had animals and plants to study. And it was there, on the island that would later be named Bering Island, just east of Kamchatka, that Georg Wilhelm Steller on November 8, 1741, first spotted a large herd of the previously unknown species of sea cow resting at the water’s edge.
It was clearly a magnificent sight, and Steller described the animals that would later be named for him in detail. From the navel up, they looked like large seals, he wrote, but below the navel they were more akin to fish. Their heads were round and not at all dissimilar from the buffalo’s. Their eyes were, despite the size of the animal, no larger than a sheep’s and had no eyelids. Their ears were hidden in the folds and furrows of their thick skin. Other than the wide tail, it lacked fins, which set it apart from the whale. “These animals live like cattle in herds in the sea,” Steller wrote. “They do nothing but eat.”
Steller not only described what the exotic sea cows looked like, what they ate, how they behaved, and how they reproduced. He also described in equal detail how fat and tasty they were, and that they were so plentiful they could have fed all of Kamchatka. He wrote that they showed no fear of humans at all. They didn’t try to escape when approached, and their only response when the starving members of the expedition caught them with large iron hooks and cut meat out of them while they were still alive was to sigh quietly.
What the sea cows lacked in survival instinct, Steller declared, they made up for in touching displays of empathy.
Signs of a wonderful intelligence . . . I could not observe, but indeed an uncommon love for one another, which even extended so far that, when one of them was hooked, all the others were intent upon saving him. Some tried to prevent the wounded comrade from [being drawn on] the beac
h by [forming] a closed circle [around him]; some attempted to upset the yawl; others laid themselves over the rope or tried to pull the harpoon out of [his] body.
One of the males, Steller wrote, even returned two days in a row to check on one of the females who lay dead on the beach. “Nevertheless, no matter how many of them were wounded or killed, they always remained in one place.”
The encounter with the languid but loving sea cows was not just a profound experience for Georg Wilhelm Steller; it was a biological sensation. Sirenians, mammals that are in fact more closely related to the elephant than the seal or the whale, are normally found only in tropical waters. This species lived on a cold, barren island far in the unexplored northern part of the Pacific Ocean, and apparently only there. Steller’s sea cow was yet another powerful example of the complexity of evolution and the mesmerizing diversity of this world. A strange living wonder in one of the world’s most inhospitable places.
But like sirens, Steller’s sea cow brought destruction on both its discoverers and itself. Vitus Bering died on the island on December 8 and was buried in the sand by the water’s edge. About half the crew shared his fate. Steller himself made it. He and the other survivors wintered on Bering Island, surviving by catching sea otters, whose flesh they ate raw. In the spring, they managed to build a new ship from the wreckage of the Saint Peter, and in August 1742, more than a year after they set off, they returned to Kamchatka, emaciated and decimated. Georg Wilhelm Steller published his observations, and was able to tell the world about the strange northern sirenians, but soon after lost himself to drink and died, just thirty-seven years old, in Tyumen’, Russia, in 1746.
And Steller’s sea cows perished, too. Russian hunters followed in Bering’s footsteps and found the languid animals to be easy prey. In 1768, only twenty-seven years after being discovered by Steller, the last sirenian was killed in the Bering Sea, and today few people even know it ever existed. It vanished from humankind’s awareness and realm of knowledge with a quiet sigh, docilely accepting its fate. Unlike the dodo, it didn’t even pass into the vernacular.
The Book of Eels Page 17