The Book of Eels

by Patrik Svensson

  One summer, Dad acquired an old wooden rowboat. He saw it advertised in the paper and bought it for two hundred kronor; we sanded and painted it out on the lawn. It was moored to the willow tree just above the rapids, and one night when we reached the stream, he suggested we row across and set up our spillers on the other side instead. The thought had never even crossed my mind, but suddenly it seemed completely rational. There was, for obvious reasons, no one on the other side at that time. And besides, it was the same stream; the difference between fishing here and fishing there was entirely theoretical. Moreover, how could anyone claim to hold the rights to something as transient as flowing water?

  “But if the train comes, we’ll have to hide,” Dad cautioned. The railway ran along an embankment next to the flat meadow. It came around a bend a few hundred yards from where we were and then ran parallel to the stream, with an unobstructed view of the meadow all the way down to the water’s edge. And maybe there would be a member of the fishing club on it this particular night who would see us poaching and sound the alarm, catching us red-handed like the criminals we were.

  We rowed across and moored the boat; I was both terrified and exhilarated. Then we picked up our things and walked along the stream, commenting on just how much more convenient this side was. It wasn’t merely the stuff of dreams, it was real, and there was no tall, wet grass to slog through and no muddy banks to slide down. I told myself it was virtually our moral obligation to fish there.

  But we set up our spillers faster than usual, glancing nervously at the railway all the while, poised to flee at the first distant sound of the approaching train. When it did come, it careered through the bend so much faster than I could’ve imagined; we turned off our flashlight and threw ourselves down in the grass. I pressed myself against the ground, doing my best to disappear among the tussocks, hiding my face and holding my breath. The train thundered past and the whole meadow was illuminated like when lightning makes time stop and I imagined we really were invisible and that my dad was lying there just like me, with his hands over his face, not breathing.

  Now I’m thinking he was probably smiling. That he wasn’t scared of being caught at all—Why would anyone care? How would they identify us?—but was playing along for my benefit. That he staged the whole spectacle to make it more exciting. Maybe he was worried I would grow tired of it all otherwise.

  I don’t know why he would have been worried about that—there was nothing I liked more—but it’s also only now, much later, that I’ve started to wonder if Dad really ever went eel fishing as a child. I’d always figured he must have. I’d always thought he and I were carrying on a tradition that had begun long before either of us. That he was doing for me what someone else had done for him and that those nights down by the river constituted some kind of continuity across time and generations. Almost like a ritual.

  But he certainly never fished with his father (the man he called Father). My grandfather (the one I called Grandfather) didn’t fish. He never did anything that wasn’t immediately useful. He worked and he rested and when he ate he did it quickly and in silence. He was teetotaler and hated the effects of alcohol; as far as I knew, he had never in his life taken so much as one day off, had never traveled anywhere, never been abroad. Wasting time and energy on something as seemingly frivolous as eel fishing was not for him. It had nothing to do with patience, it was more a matter of obligation. The narrow path looks different to different people.

  Maybe Dad fished alone, or with someone else entirely, but if so, I don’t know anything about it. I remember Dad telling me how much fish there used to be in the stream a long time ago, about how the bottom crawled with eels and how the surface turned silver when the salmon traveled up it in the spring. But he didn’t speak from experience; these were stories from before he was born that he’d picked up somewhere. His own stories about caught or lost eels I knew already, because I’d been there with him. His stories were my stories. It was as though there had been nothing before us.

  Was that the case? Did it start with the two of us? If so, did it have anything to do with the fact that the person he called Father and I Grandfather was really someone else? Were our nights by the stream an attempt to compensate for something my dad hadn’t had, to realize his own vision of what a father and son could be to each other? A way of forging his own narrow path through life?

  7

  The Dane Who Found the Eel’s Breeding Ground

  How far do you have to be prepared to go to understand an eel? Or a person? Johannes Schmidt was twenty-seven years old when he stepped aboard the steamship Thor in 1904 and set off to find the birthplace of the eel. It would be almost twenty years before he reached his destination. A few years after he did, a British marine biologist, Walter Garstang, would write an ode to Schmidt, which was eventually published in what might very well be the only collection of poems ever written about the larval stage of various animals, Larval Forms, with Other Zoological Verses.

  All honour to the Danes who solved

  This age-old mystery,

  Who, step by step, and year by year,

  Revealed the history:

  Johannes Schmidt the leader,

  With “Papa” Petersen behind,

  Who made the “Thor” and “Dana” ships of fame

  For all mankind

  Quite a lot had happened in humankind’s dogged quest to understand the eel’s life and existence since Sigmund Freud’s fruitless search for testes in Trieste. A Danish marine biologist, C. G. Petersen, had in the 1890s managed to observe the last metamorphosis of the eel and proposed that all eels reproduce in the sea. Even Aristotle had, as we know, noticed that fully grown eels sometimes move out into the sea, and in the seventeenth century, Francesco Redi had noted that glass eels appear along the coasts in the spring and wander up rivers. But Petersen was able to describe how it happens in more detail. In particular, he successfully observed and described how yellow eels turn into silver eels. Until then, a lot of people were unconvinced that the two belonged to the same species. Petersen demonstrated unambiguously that they were each manifestations of the same fish. He saw the silver eel’s digestive organs shrink and saw it stop eating, saw its reproductive organs develop and its fins and eyes change. The transformation was apparently the eel’s way of preparing for procreation.

  In 1896, two Italian researchers, Giovanni Battista Grassi and his student Salvatore Calandruccio, had also explained the first metamorphosis of the eel. They had made a comparative anatomical study of different kinds of larvae caught in the Mediterranean to glass eels, and drew from it the conclusion that a small creature shaped like a willow leaf called Leptocephalus brevirostris must be the very first form of the European eel, Anguilla anguilla. This larva had previously been believed to be its own species. Now it became clear it was in fact an eel. What’s more, Grassi and Calandruccio were also the first people ever to witness the metamorphosis, when a small willow leaf in their aquarium in Messina on Sicily miraculously turned itself into a glass eel.

  It was a sensational discovery. “When I reflect that this mystery has occupied the attention of naturalists since the days of Aristotle, it seems to me that a short extract of my work is perhaps not unworthy to be presented to the Royal Society of London,” Grassi wrote in a report that would eventually be published in what was at the time one of the world’s most prestigious scientific journals, Proceedings of the Royal Society of London. In his report, Grassi also noted that this particular kind of larva, which had now been shown to be the first incarnation of the eel, had relatively large eyes and consequently was probably hatched at great depths. Possibly, he proposed, in the Mediterranean.

  By the early twentieth century, it was known, then, that the yellow eel turns into the sexually mature silver eel and wanders back into the sea in the autumn, never to return. It was also known that leptocephalus larvae turn into tiny, delicious glass eels that appear around the coasts of Europe in spring in search of a place where they can live
and transform themselves into fully grown yellow eels. But what happens in between? And where does it happen?

  When the German zoologist Carl H. Eigenmann gave a speech to the American Microscopical Society in Denver, Colorado, in 1901, he entitled his lecture “The Solution of the Eel Question.” It was not intended literally. He was still unable to provide the ultimate solution to the eel question. On the contrary, he cited a scientific anecdote according to which “all important questions have now been answered, save the eel question.” But, Eigenmann explained, the question itself had changed. Before, the eel question had been about what the eel truly was, a fish or something else altogether. It had been about the eel’s propagation—about finding its reproductive organs, about whether the eel gave birth to live young, whether it was hermaphroditic or not—and about what its metamorphoses signified.

  But now, at the dawn of the new century, the eel question was this: What do mature eels do after moving back into the sea? When and where do they breed? And where do they die?

  SO WHERE DID THE SILVER EELS GO? AND WHERE DID ALL THE MYSTERIOUS willow leaves come from? Where was the eel’s birthplace? That was what the twenty-seven-year-old Johannes Schmidt set out to find in the spring of 1904.

  Johannes Schmidt was a marine biologist from Denmark. He lived his first few years in a small redbrick house on the grounds of Jægerspris Castle on North Zealand, about thirty miles north of Copenhagen, where his father was the steward. He was brought up in a warm and sheltered environment, surrounded by woods and nature, far from the big city and the world of science, and even farther from the Sargasso Sea.

  At the tender age of seven, however, Johannes Schmidt lost his father, and he, his mother, and his two younger brothers were suddenly forced to move to Vesterbrogade in Copenhagen, one of the city’s liveliest streets, and to a very different kind of life, surrounded by different kinds of people. It was an upheaval that affected Johannes Schmidt’s life not only emotionally but also practically. The Carlsberg brewery was located just a few hundred yards from his new home, and even closer was the home of Johannes Schmidt’s uncle, Johan Kjeldahl, who worked as a chemist at Carlsberg’s research laboratory, where Schmidt would eventually begin his own scientific career.

  The same year the seven-year-old Johannes Schmidt moved to Copenhagen with his family, the world-famous chemist Louis Pasteur visited the city. Pasteur had developed a method for protecting food from bacteria and microorganisms; pasteurization, as it had been named in his honor, had been hugely significant for beer breweries. When Pasteur came to Copenhagen, he was consequently invited to visit Carlsberg, and a proud J. C. Jacobsen, the brewery’s owner, was so impressed by the great scientist he decided to invest in a sophisticated in-house research laboratory. In addition to brewing beer, Carlsberg would also pursue modern, advanced research. And not just about beer making and food conservation but groundbreaking basic biological and natural scientific research. It was a matter of prestige but also a commercial calculation. Over time, it helped Carlsberg grow from a small family-owned brewery to one of the world’s largest, while the company’s research department would also, in roundabout, indirect ways, contribute to bringing the eel and humankind a little bit closer together.

  After moving to Copenhagen, during his first years at school, Johannes Schmidt began to spend more and more time in the Carlsberg research laboratory, shadowing his uncle Johan Kjeldahl, with whom he also lived for a time. It was there, in the laboratory, that he learned the basics of scientific work. It was also where a passion for science—that compelling need to observe, describe, and understand—was awakened in him. When he eventually embarked on his successful academic career, and traveled the world in pursuit of his research, it was with the financial support of Carlsberg.

  Johannes Schmidt received a degree in botany and a grant to study the vegetation of what was then known as Siam (now Thailand) in 1898. In 1903, he submitted a doctoral thesis on mangroves, only to immediately switch his focus to marine animals.

  On September 17, 1903, he married Ingeborg van der Aa Kühle, whom he’d known since he first came to Copenhagen at the age of seven and who was the daughter of Søren Anton van der Aa Kühle, the successor to J. C. Jacobsen as director of Carlsberg. The wedding took place in Carlsberg’s own church, the Jesuskirken in Copenhagen, and in the spring of 1904, the couple acquired an apartment of their own on Østerbrogade. They had barely moved their furniture in before Johannes Schmidt set sail to find the origin of the eel.

  “THE PROBLEM OF THE PROPAGATION AND BREEDING PLACES OF the Common or Fresh-water Eel is one of great antiquity,” Johannes Schmidt would later write in a report to the Royal Society of London. “From the days of Aristotle naturalists have occupied themselves therewith, and in certain regions of Europe it has exercised popular imagination to a remarkable degree.”

  He wrote places, in the plural, because how could anyone know for certain there was just one breeding place? And he lingered on that enticing enigma, the one that had for centuries occupied so many scientists and that had now apparently ensnared him as well.

  “We know, then, that the old eels vanish from our ken into the sea, and that the sea sends us in return innumerable hosts of elvers. But whither have they wandered, these old eels, and whence have the elvers come? And what are the still younger stages like, which precede the ‘elver’ stage in the development of the eel? It is such problems as these that constitute the ‘Eel Question.’”

  More specifically, there was one aspect of the eel question that bothered Johannes Schmidt. His Italian predecessors Grassi and Calandruccio had proposed that the eel, or at least the Italian eel, reproduces in the Mediterranean, since that was the only place they had found leptocephalus larvae. But at the same time, the larvae caught in the Mediterranean were large, three to four inches long, and clearly not newly hatched. How come no one had ever found smaller specimens?

  As early as May 1904, mostly through sheer happenstance and before his mission had technically been made official, Johannes Schmidt managed to catch a leptocephalus larva in the sea just west of the Faroe Islands. It, too, was large, three inches long, but it was the first time anyone had seen an eel larva outside the Mediterranean, and it convinced Schmidt that Grassi and Calandruccio were likely mistaken about the eel’s breeding ground. Schmidt also realized that in order to solve the mystery, he would have to trace the eel back to its source, looking for ever-smaller larvae, until somewhere in the vast ocean, he found the first newly hatched willow leaf, and thus the birthplace of the eel. He needed to find a needle in a haystack. And the haystack was an ocean.

  “I had little idea, at the time, of the extraordinary difficulties which the task was to present, both in regard to procuring the most necessary observations and in respect of their interpretation,” Schmidt would later write. That was, by all accounts, a polite and conservative understatement.

  Between the years 1904 and 1911, Johannes Schmidt patiently sailed up and down the coasts of Europe with a trawl: through the waters off Iceland and the Faroe Islands in the north, across the North Sea off Norway and Denmark, south along the Atlantic coast of the continent, past Morocco and the Canary Islands, and into the Mediterranean, all the way to the Egyptian coast. He found lots of leptocephalus larvae, but they were all more or less the same size as the first one he’d caught, between two and half and three and a half inches.

  After more than seven years of searching, he was still stuck on square one, and evidently plagued by a certain degree of despondency. “The task was found to grow in extent, year by year, to a degree we had never dreamed of,” he wrote. “And this work has been handicapped throughout by lack of suitable vessels and equipment, and by shortage of funds; indeed, had it not been for the private support afforded from numerous different sources, we should have had to long since relinquish the task.”

  He had at least felt able to draw one firm conclusion: since all the larvae he’d found along the coasts of Europe were relatively large and evident
ly not newly hatched, he’d realized that eels probably do not reproduce near the coast and that his search would have to continue considerably farther out to sea. For this, the steamship Thor was insufficient; instead, Johannes Schmidt was able to enlist the aid of Danish shipping companies that sailed the Atlantic. He equipped their ships with nets and instructions, and between 1911 and 1914, twenty-three large freighters participated in the search for the tiny, transparent larvae. Their crews had no scientific training and no equipment other than the trawling nets Schmidt had given them, but they were under instruction to drag the nets along behind them, mark where they raised them and send their catches to the laboratory in Denmark. More than five hundred catches were logged by the freight ships covering large swathes of the northern part of the Atlantic.

  Schmidt for his part set off in the summer of 1913 on the schooner Margrethe, which a Danish company had lent him. He scoured the waters all the way from the Faroes to the Azores, west toward Newfoundland and then south in the direction of the Caribbean.

  The intensified search yielded results. Before long, Johannes Schmidt found that the eel larvae became more numerous as he moved west, while their size decreased. At one point, about halfway across the Atlantic, between Florida and West Africa, he caught a larva measuring only 1.3 inches, a new record. Eventually, pushing even farther west, he found a specimen measuring less than 0.7 inches.

  Schmidt collected all the fragile leptocephalus larvae, from both his own expeditions and those of his helpers, studied them under a microscope, measured them, and kept meticulous notes: length and number, depth and date, latitude and longitude. Slowly but surely, he built up an enormous collection of data, which guided him, almost imperceptibly slowly, toward his goal. Among other things, he was able to discern a link between the tiny willow leaves’ movements across the Atlantic and the mighty ocean currents. He also found something else, almost by chance.