An excerpt from
Nature in America at the Time of Discovery
The Discovery Of Paradise
At first sight, the coasts of Labrador and Newfoundland are bleak, inhospitable places. It’s a sobering thought that if not for the Gulf Stream, that great river in the North Atlantic conveying heat from the tropics to the shores of Europe, we Britons would share this climate. But these places aren’t that bad. This barren-looking scenery refreshes the soul; here a human can understand his place in the world. Nothing can hide from a searching Newfoundland wind, not even the arrogance of a species that thinks itself master of all it surveys.
Besides, these places are far from barren; you just need to know where to look. All you need to do is smell the wind, laced with the pungent aroma of ammonia. Follow your nose to the cliff tops and a cacophony of grunts and squeals rises to greet you. There below you the rocky stacks are crowded with gannets, perched on every available space. Riding the wind on elegant, ink-dipped wings, returning birds hang motionless in the air over their mates, until they’re sure they’ve found the right spot, a familiar call among the symphony. But, as impressive as the smell and din always is in these colonies, it was once even more impressive. Some of the largest seabird colonies in the world used to exist around the coasts and islands of northeast America. A French explorer in the mid-1500s once declared: “All the ships of France might load a cargo of them without once perceiving that any had been removed.”
And there’s a good reason for such unimaginable numbers of birds; the seas and shores around these colonies used to be filled with an equally inconceivable abundance of fish. It was these teeming shoals that drew Europeans here in the fifteenth century, but our first glimpse into this crowded ocean didn’t come from French or English explorers, nor even from the Spanish who, to most people, were seen as the first to encounter the New World. They’re found in two Norse sagas that date to nearly five hundred years before Columbus blundered into the Caribbean. These first recorded encounters don’t tell us a great deal about the ecology of the New World, but they do introduce us to the story of the Atlantic salmon, which is a good illustration of the way history interacts with biology and introduces many of the broad themes that will recur throughout the following chapters.
The Vikings were unrivalled in their seamanship and exploration. By the middle of the 800s, they had begun to settle Iceland, though when they first got there, the island was already populated by Irish monks, who promptly left to find peace and quiet elsewhere. For the Vikings, in the long term, Iceland turned out to be a staging post as well as a new homeland. They pushed further west and had established colonies in Greenland by the tenth century, almost on the doorstep of the American continent.
How they made the final step to the New World is recorded in two sagas, The Saga of the Greenlanders and The Saga of Eirik the Red. The Norse and Icelandic sagas are actually just elaborate family histories, with a touch of adventure for added effect, so they don’t always dwell on the natural wonders that these early explorers must have found. And although these two sagas, which describe the same events, disagree in details, they nevertheless provide tantalizing glimpses into the North American continent long before major European contact.
The story begins in the closing years of the first millennium in Norway, from where Eirik had just made a hurried departure to escape punishment for murder. His plan was to settle in the now-thriving colony in Iceland, but it didn’t take him long to become unpopular there as well. He gained his name “Red” from the color of his hair, but it might just as well have been from the trail of blood he left behind. When he became involved in a local feud and decided that life in Iceland was also getting just a little too hot, he remembered that a friend called Gunnbiorn had once run into a landmass to the west of Iceland after being blown off course. Eirik decided it would be expedient to go and find it, and to settle there if he could. He did find land and returned to pick up volunteers for his settlement. He decided to call the place Greenland, perhaps an attempt to make it sound more attractive to potential settlers, just as the first colonists in America half a millennium later would send back descriptions of Paradise to encourage expansion of their own settlements in the New World.
Eirik’s simple publicity stunt obviously worked. These hardy Norse souls did indeed manage to build several settlements along the southwest coast of Greenland. Among deep fjords that would have reminded them of Norway, they found places where sheltered harbors led up to fertile pastures for their tough little cattle. In addition, the coasts to the north were alive with seals and walrus. Offshore there were great shoals of fish and whales and on land plenty of ducks and caribou, so it didn’t take long for a regular trade to build up between Eirik’s Greenland, Iceland, and Norway. They traded whale and seal oil or eider duck feathers for such staples of life that they couldn’t provide for themselves in their remote colonies on the edge of the known world. The success of these colonies depended on regular communication with Iceland and mainland Europe, and that meant sea traffic through difficult and often dangerous waters. Sooner or later something was bound to go wrong.
It did, and it happened to one of history’s unsung heroes, a man by the name of Bjarni Herjolffson. The details of his story are preserved in only one of the sagas, The Saga of the Greenlanders, which tells how he was blown off course as he sailed between Iceland and Greenland. He eventually sighted land, which most now agree was somewhere along America’s northeast coast. He sailed north along this coast, making his way back toward Greenland, but he never bothered to land. If he had, history might have been kinder in recording him as the first undisputed European discoverer of the New World. As it happens, that honor is usually given to Leif Ericsson, son of Eirik the Red, who decided to follow up on Bjarni’s discoveries fifteen years later.
So, in the early years of the second millennium, we get our first glimpse into the nature of North America. Around AD 1000, Leif sailed west from Greenland and encountered land. At first he wasn’t impressed. He found a barren land of flat stones, which he called Helluland—“slab land.” It is now generally agreed that this was Baffin Island, and Leif’s description is still a good summary of the place today. Sailing south, things improved. Next he landed at Mark-land—“wood land”—covered in fine, large trees. Two days sailing further to the south and west, Leif stopped and built houses ready to overwinter in this strange land. The abundance they found soon impressed them. “There was no lack of salmon in the river or the lake, bigger salmon than they had ever seen. The country seemed to them so kind that no winter fodder would be needed for livestock; there was never any frost all winter and the grass hardly withered at all.”
So where were they? The general consensus was that they had landed somewhere on the coast of Labrador or Newfoundland, which makes their descriptions of the mild winters sound like a bit more Paradise publicity. However, the reason that the Vikings had been able to colonize Greenland successfully was that they did so during a period of climatic warming, so perhaps the coasts of Labrador and Newfoundland were less bleak than they seem today. Some flesh was put on the bare bones of the sagas in 1960 when, nearly a thousand years after Leif Ericsson, two more Norwegians landed on the coast of Newfoundland. Helge Ingstad and his wife, Anne, were both archaeologists, searching for evidence of their distant ancestors in the New World. What they found was astounding.
A local fisherman told them of an ancient settlement long thought to have been made by Indians. But when the Ingstads visited this site, at l’Anse aux Meadows on the very northern tip of the island of Newfoundland, they saw the unmistakable outlines of Viking long houses, familiar from their work back home in Norway. If that wasn’t convincing enough, they returned in successive years to excavate the site and found evidence of iron smelting, something no Indian had even heard of before 1492. Carbon 14 dating from the iron hearths gave figures around AD 900–1070, so it seemed the story was closed. L’Anse aux Meadows was the reality behind the sagas. But the saga isn’t finished yet.
The Saga of the Greenlanders describes another discovery that caused some consternation among later scholars. One of the party wandered away from the settlement and, when he returned, reported that he’d found the place festooned with wild grapes. There’s nothing too astounding about this. Many later explorers found the trees along the east coast covered in a dense growth of vines sporting wild grapes finer than any in Europe’s vineyards. The abundance of wild grapes impressed the Norsemen so much that Leif Ericsson called this area Vinland or “Wine-land.” But no wild grapes grow in the far north of Newfoundland today. Does this make l’Anse aux Meadows unlikely as Leif’s first settlement? Perhaps, though the Vikings were exploring during a period of warmer climate that probably meant that the range of many plants and animals, including wild grapes, extended further north. So did the saga-tellers leave any more clues?
Leif thoughtfully measured the day length at the winter solstice, which gives a good indication of latitude. “In this country, night and day were of more even length than in either Greenland or Iceland; on the shortest day of the year the sun was already up by 9 am and did not set until after 3 pm.” This should put the general location beyond doubt, but the translation above is deceptively simple. Actually, Leif recorded the sun’s position using arcane Viking terminology, and the translation into a specific latitude involves complex calculations and a few assumptions that have led to suggestions for Vinland being as far south as Florida! Other calculations point to a location somewhere to the south of the Gulf of St. Lawrence, and well within the range of Vitis riparia, the most widespread of a score of wild grape species that grow across America. V. riparia pushes north into New Brunswick and northern Quebec, so perhaps Leif’s first settlement was around the Bay of Fundy, along the coasts of Nova Scotia or New Brunswick.
The abundance and size of the fish they recorded doesn’t help. We’ll see from later descriptions that all the rivers and lakes down the east coast were choked with so many fish that it left those early explorers lost for words. So it seems the exact location of Vinland must remain a mystery, though in a way it doesn’t matter. We can still stand with those brave Norsemen, somewhere on the northeast coast of the continent, and see a vitality of nature already gone from most parts of Europe.
We can imagine that small party standing on the banks of a river, staring at water alive with the flashing silver backs of Atlantic salmon. Most of the fish are huge, on average around twenty-five pounds each, but there are plenty that are easily twice this size. They must measure four or five feet from head to tail. It’s the height of a late summer run, up river to spawning grounds on exposed gravel beds, and the river is almost solid with fish. It looks as if you could cross without getting your feet wet. These fish were born in this river but have spent the last year or two at sea, feeding and growing. Now they are returning with an almost unerring accuracy to that same river again to lay their own eggs and continue a cycle that began at the end of the last ice age. Many will die after spawning, though a fair proportion will survive to swim to sea again and return to spawn in later years. Atlantic salmon also run up the rivers of Scandinavia, so the sights in Labrador must have been spectacular indeed to have been worthy of recording in the sagas.
Behind the Norsemen, the setting sun is now filtered through arching branches of massive trees, hung with curtains of purple grapes. The vines scramble up every tree, disappearing into the fading light. With the light finally gone, the Norsemen huddle close to their fire, warming themselves against an early fall chill that descends with startling suddenness as soon as the sun disappears behind the unknown land to the west. But none can sleep. The noise coming from the river is almost deafening, like the applause of a vast unseen crowd. The giant salmon are leaping over each other, over cataracts, over and over, falling back into the water with great splashes.
What the Norsemen couldn’t have known was that this was being repeated for many hundreds of miles up and down the coast; by one estimate, three thousand such rivers provided hundreds of thousands of spawning beds for an incalculable number of Atlantic salmon. Certainly, Atlantic salmon would have run up the rivers as far south as the Housatonic, which flows into Long Island Sound, not far from New York City. To the north, they ran in numbers all the way up to Ungava Bay, on the Canadian mainland opposite Baffin Island.
And this spectacle would repeat itself year after year. Seven centuries after the Norsemen left these shores, Nicolas Denys also has sleepless nights on the Miramichi River flowing through New Brunswick in Canada:
So large a quantity of salmon enters the river at night one is unable to sleep, so great is the noise they make in falling upon the water after having thrown or darted themselves into the air passing over the river flats.
Salmon were still hugely abundant when the New England colony had grown from its beginnings as a handful of starving pilgrims, and it’s said that servants along the Connecticut River would only work on the condition that they were not fed salmon on more than two occasions each week. As splendid a comment as this is on the abundance of salmon, Robert Behnke, who wrote a definitive work on trout and salmon in North America, can find no basis in fact for what has become an often repeated myth. Nevertheless, it doesn’t alter the fact that, from Long Island Sound to Ungava Bay, Atlantic salmon abounded.
In 1770, George Cartwright, recently retired from the army, sailed from England to Labrador to set up trading posts for fur and fish. The sheltered harbor where he started his enterprise still bears his name. The community of Cartwright, population 628, stands on the eastern side of Sandwich Bay, not far from thirty-three miles of pristine sandy beach that was impressive enough for Leif Ericsson to call it Wonderstrand. It’s still an amazing place a thousand years later. There are large gannet, puffin, and guillemot colonies within a few miles, and Cartwright claims to have the best fly-fishing for Atlantic salmon anywhere in the world. While that claim might be disputed by some, salmon were certainly one of the things that drew George Cartwright here over two hundred years ago. And he kept meticulous records, not just of his salmon operation but of all the wildlife in the area.
For someone trying to earn his living from fish, Labrador must have seemed like Paradise indeed. The salmon runs in the White Bear River were so dense that George reckoned “a ball could not be fired into the water without striking a salmon.” Between June 23 and July 20 on one river he and his three companions killed 12,396 salmon, and they felt they could have killed thirty thousand if they had left their nets out. Elsewhere, fishermen only gave up catching salmon when they ran out of salt to preserve the fish. Whatever the modern community of Cartwright boasts about its salmon fishing, I doubt it’s anything like it used to be.
But Atlantic salmon, on both sides of the ocean, have had a hard time of it since George’s day. They disappeared totally from many rivers in both Europe and America. I remember the fanfares that greeted the first salmon for many years to brave the River Tees in Middlesbrough, in northeast England, the town where I grew up. The lower Tees is hemmed in by industry: a tangle of chemical works, steel foundries, and docks. They all emptied waste into the river, and although the upper reaches, with their bare gravel spawning beds, still flowed cool and clear through the dales of Yorkshire and Durham, the toxic concoction near the river mouth was as effective as any physical barrier in preventing the salmon from running upstream. And, to return to the rivers of their birth, salmon use the unique aroma of their particular river, percolating through salt water, drifting on ocean currents, to find their way. What rivers like the Tees and many others must have smelled like to the salmon’s sensitive nose is anyone’s guess. I spent many of my weekends watching birds on the Tees Estuary in the early 1970s, and the air there smelled bad enough to my insensitive human nose. To fall into the river around here meant a trip to hospital and an undignified encounter with a stomach pump. So any salmon foolish enough to come too close, even if it could have detected the delicate scent of Teesdale on the water, would soon have gasped its last.
Huge efforts have been made since then to clean up many of these rivers, and salmon have responded. Although most salmon return to the rivers where they hatched, a very small percentage—the Leif Ericssons of the salmon world—explore new territory. These pioneering fish can naturally recolonize rivers, even if all the river’s native fish have long since been eliminated. Thus, the first salmon in living memory returned to the Mersey, in northwestern England, in 2001. By then eighty to a hundred salmon per season were being reported in the higher reaches of the Tees, so presumably many more were running the gauntlet of the concrete and steel-fringed estuary. Similarly, salmon began to run once more in the rivers of Newfoundland and New Brunswick, Nova Scotia, and Quebec. But what happened to transform astonishment at limitless abundance into mere delight at the sight of a few hundred? It wasn’t entirely the fault of George Cartwright.
The problem is that there are lots of ways to kill salmon. Certainly, George and his fellow commercial fishermen contributed. Before the early 1700s, there wasn’t much interest in actually eating the salmon, but they were hauled out of the river to feed hogs or dumped in their thousands on the fields as a substitute for manure. It’s often said that the first settlers in New England were shown how to grow crops by the Indians, who taught them to bury a fish as fertilizer in a mound of earth, before planting it with corn. If so, the Indians can have only stared on in disbelief at the profligate enthusiasm with which later settlers adopted this practice.
Then, after about 1700, Europe developed a taste for salted or smoked salmon. This huge market supported men like Cartwright in growing numbers, and by the end of the eighteenth century some estimates put the total salmon exports from North America in excess of 30 million pounds each and every year. Massive seine nets spread across the entrances to rivers mopped up most of the fish trying to enter. Often the numbers were so great that the nets simply burst. But being caught for human or hog consumption or as substitute manure wasn’t the only problem facing salmon.
To support the expansion of towns and cities along the east coast, rivers were being dammed and water mills built. Then, later, iron smelters and tanneries began to pollute the pristine waters. Finally, as the human population grew, ever-increasing quantities of sewage flowed into the rivers, so both physical and chemical barriers began to impede any fish that escaped the nets. The Connecticut River lost its salmon to a dam in 1798, presumably a cause for great celebration among the working people there, if they really were trying to avoid overdosing on fish. And still the problems for salmon mounted. Wood was needed for ever-expanding building, so sawmills sprang up to serve each new township. Great rafts of logs were floated down river and destroyed the gravel spawning beds. Any that survived often ended up buried in sawdust from the lumber mills. Salmon can only spawn in clean gravel, so the few that finally made it upstream usually found they’d made a wasted journey.
In the late 1800s, a new market, in tinned salmon, stimulated the fishery, and since most of the rivers near the big population centers in New England had lost their fish, the last wild rivers of the Labrador coast were soon being plundered. The writing was on the wall. A few farsighted people could see what was happening, though, as still happens today, no one took much notice until it was way too late. One of the most eloquent of these observers was an English visitor to Canada around 1870 named John Rowan. “Thirty years ago, the salmon fishing in Nova Scotia was superb. But where nature is so bountiful in her gifts man rarely appreciates them. It would really seem that Nova Scotians hate the salmon. Overfishing is bad enough, but to shut the fish out of the rivers is little better that insanity.… By and by, when the forests have been destroyed and the rivers rendered barren, Canadians will spend large sums of money in, perhaps, fruitless efforts to bring back that which they could now so easily retain.” How right he was. In Great Britain alone, the cost of cleaning up just the sewage has climbed to over £30 billion. Industry has had to spend billions more to clean up its act.
But there’s one final twist in the salmon’s tale. Despite well-publicized returns to once-polluted rivers, Atlantic salmon populations have fallen dramatically over the last few decades right around the ocean. In November 2000, Maine, the only U.S. state with any remaining wild salmon runs, listed several of its distinctive genetic stocks as endangered. And not before time. As few as fifty fish may have returned to these rivers the year before. Six months later, in May 2001, the Committee on the State of Endangered Wildlife in Canada met to declare Atlantic salmon in the Bay of Fundy endangered.
Paradoxically, Salmo salar is much more common now than it ever was in the days of Leif Ericsson or George Cartwright, and it lives in many more places around the world, but these aren’t the powerful fish flashing silver through white water that fill the early accounts of the northeast coast. These are pallid ghosts, penned in the sea cages of salmon farms, fed bulk food and doctored with high-tech medications. These fish have never leapt up a falls in their lives. Yet they may pose a real threat to their wild brethren.
The recent decline in wild salmon stocks has mirrored the exponential rise in fish farms, whose nets often lie just offshore, close to salmon rivers. Salmon farmers around the North Atlantic produced 4,783 metric tons of fish in 1980 and 658,735 metric tons in 2000, well over a hundredfold increase in just twenty years, and since then farmed salmon production has remained around 700,000 metric tons a year. But, as any good statistician will tell you, correlation doesn’t imply causality. Those on the side of wild salmon cite pollution from the crowded nets in the form of fish sewage and antibiotics and other drugs used to boost fish growth or increased populations of parasites like fish lice. These claims are just as vehemently denied by the fish farmers. But it now seems that one of the biggest problems is the fish themselves or at least those that escape the cages. Each year so many salmon find their way off the farm that their numbers would have astounded even George Cartwright. In 2002, one estimate suggests 2 million salmon wriggled their way to freedom in the North Atlantic. Friends of the Earth has provided a list of these “great escapes,” at least those that have been reported. One of the largest, in Scotland in 2000, involved a breakout of some 395,000 fish, but the single largest was in the Faeroes, involving six hundred thousand fish. Overall, the numbers of escaped farm fish swimming in the Atlantic may be enormous. Some researchers suggest that 40 percent of fish caught in the Atlantic are of farm origin, while researchers in Norway found that up to 80 percent of salmon entering Norway’s rivers were nonnative. But does it matter, so long as there are still salmon swimming up river?
Because most wild salmon return to the rivers of their birth, there is very little movement of genes between populations. Over time, each river has therefore developed its own distinct genetic forms of Atlantic salmon. Farmed fish, on the other hand, come from a variety of sources, and through generations in captivity have acquired a very different genetic makeup from wild salmon. Once they’ve tasted freedom, instinct guides farmed fish into freshwater; and though they might be flabby couch potatoes compared to their wild cousins, they can interbreed with wild fish, introducing foreign genes into the distinctive gene pools of local fish. But why does this matter? After all, they are all Atlantic salmon.
The answer to that depends on how the distinct local genetic forms of wild salmon arose in the first place. The genes of isolated populations can diverge for two reasons. The first is “genetic drift,” a process where random changes in genes that have no effect on survival gradually accumulate in the population purely by chance. The smaller a population, such as salmon from one isolated river, the greater the potential for such drift. The other way is through classic Darwinian selection. In this case, the distinct gene pools in each river would represent adaptations to specific local conditions. In the first case, crossbreeding with farmed salmon might not be of much concern; in the second, it could dilute exquisitely honed adaptations and threaten the continued existence of wild salmon. The weight of evidence suggests the latter.
Different populations of salmon differ in many ways, including the timing of their spawning runs and their migration to the sea. Recent work is now suggesting that such differences are under the control of those distinctive local genes. Entering the ocean, for example, requires big physiological changes. Different enzyme systems must be activated in the gills to rid the fish of excess salt as it swims from fresh into saltwater, and these enzymes activate at different times in different genetic strains. These differences correlate very precisely with the timing of the run to sea in different populations.
If more proof were needed, modern DNA analysis, familiar from TV crime thrillers, has also been used to study the genetic makeup of salmon populations in a number of Danish rivers through time. Scales from fish caught between 1913 and 1989 had been stored in collections and can yield enough DNA for modern techniques to show that the local genetic patterns have remained constant over this whole period. This too suggests that the distinct local gene pools are indeed adaptations to local conditions, maintained by natural selection, and not random changes over time.
Although recent studies show that, over their lifetimes, farmed fish are less than a fifth as effective at breeding as wild fish, this is enough to worry scientists. Experiments have shown that the hybrids of farmed and wild fish are much less successful at surviving than purebred wild fish. And a quirk in the salmon’s breeding behavior means that such hybrids might be more common than expected from the poor competitiveness of farmed fish.
When salmon eggs hatch, the young fish spend two or more years as juveniles, called parr, living in the river of their birth. After that they turn into silvery smolts and head down to the sea. Once in the ocean they can feed in highly productive waters that allow them to grow to much larger sizes than they could if they simply stayed at home. After a period in these rich ocean feeding grounds, the salmon reach sexual maturity and return to the rivers to spawn. But these fish have a decision to make. Spawning is very competitive for the males, so the bigger they are, the more likely they can battle their way to fatherhood. And for the females, the bigger they are the more eggs they can lay. So in some ways, it pays a salmon to spend a longer time at sea, feeding and growing. On the other hand, not returning to the spawning river delays the arrival of their first offspring, and there’s the distinct risk of ending up inside a killer whale or seal before getting a chance to spawn. So some salmon return early, after just one winter at sea, while others spend two years at sea. But for males there’s another, much sneakier, alternative. They could mature sexually while still parr.
The production of sperm doesn’t take a lot of energy, especially compared to the production of eggs, so males don’t need to be big just to produce sperm. These parr simply stay in the relative safety of the rivers where they hatched and wait for fish returning from sea to spawn. They can’t compete with the massive, ocean-fed males directly, but their small size means they can use a different strategy. They wait until a female drops her eggs, then sneak in and fertilize a few without her guardian male even noticing. Adult farmed salmon might lose out in competition with wild fish, but it turns out that the story is reversed for parr. Fish farmers, like farmers since the dawn of agriculture, have selected their animals to be fast growing to reach market size as quickly as possible, so escaped farm parr are much faster growing and also much more aggressive than wild ones, and this gives them an edge on the spawning beds. To see what was actually happening on the spawning beds, scientists fitted wild and farmed parr with tiny microchips so they knew who was who and monitored their activity with underwater surveillance cameras. After spawning, the DNA of the eggs was analyzed to check who had fathered what. The results were conclusive: wild parr had managed to father only a quarter of the eggs.
The demand for copious and cheap salmon means that salmon farmers are always looking for new ways to expand their operations and their profits. Genetic engineering offers the technology to make salmon grow much faster to marketable size, but if such genes pass to wild salmon, they could have even more disastrous results. Proponents of aquaculture argue that such farm-produced fish have the capacity to ease pressure on wild fish stocks, though, since it takes around three pounds of wild caught fish to grow each pound of farmed salmon, salmon farming really only shifts the pressure from one set of overtaxed marine resources to another. In a nutshell, salmon farming is a big and expensive business driven by a desire to maximize short-term profits, and that, as we shall see in the following pages, is never good news for natural resources.
The changing fortunes of Atlantic salmon illustrate the close relationship between history and ecology and how complex this relationship is. The details of this history are shaped by the specific biology of salmon and can only be fully appreciated through an intimate understanding of that biology. In the following chapters I will amplify the broad themes of this chapter with a range of other species, as diverse as mammals and mollusks, each with their own distinct biology that has helped fashion each unique history. The other half of such histories is driven by the motives and reactions of people, shaped by historical and cultural circumstances. The social and historical factors that shaped this new dialogue with nature varied with time and place, each a fascinating study in its own right. But, equally fascinating, common themes begin to emerge that throw our own relationship with the world around us into sharp focus.