Environmental Science

Introduction

I have always found it difficult to think about the story of my life, let alone tell it. I suffered great traumas as a child. To protect myself, I took my pain and put it down a deep well in my mind. I hid it from myself so that I could function, and I moved through my entire scientific education and decades of research with my eyes always cast ahead, looking for the next question, the next answer, the next piece of understanding and wisdom.

But the person I am today could not exist without that trauma. It led me, as a thirteen-year-old girl, on stepping stones to one of the last bastions of the Celtic culture in Ireland, a place called the Lisheens Valley in County Cork. I arrived in Lisheens in need of something to help hold me together just as the place itself was falling apart. The ancient knowledge of the Druids and the Brehon Laws, kept safe,refined and handed down from one generation to the next for millennia, was on the verge of being lost. Instead, it was given to me, an understanding of the healing powers of plants and the sacred nature of the natural world that remains the greatest gift I have ever received.

The only thing asked of me in exchange for that gift wasthat I not keep it to myself. And though I have shared my ideas and discoveries freely during my fifty-year career in science,I have always held pieces of my story back, keeping the complete picture obscured even from myself.

But now we find ourselves in a special time. On the one hand, climate change poses the most significant threat to our planet that humanity has ever faced. On the other, we are better equipped than ever before to take on that challenge.To do so, though, we need to understand the natural worldas people once did. We need to see all that the sacred cathedral of the forest offers us, and understand that among thoseofferings is a way to save our world.

We are all woodland people. Like trees, we hold a genetic memory of the past because trees are parents to the child deep within us. We feel that shared history come alive everytime we step into the forest, where the majesty of nature callsto us in a voice beyond our imaginations. But even in those ofus who haven’t encountered trees in months or even years,the connection to the natural world is there, waiting to be remembered.

In telling the story of my life and the leaves, roots, trunks, bark and stems that weave all through it, I hope to stir that memory. I want to remind you that the forest is far more than a source of timber. It is our collective medicine cabinet. It is our lungs. It is the regulatory system for our climate and our oceans. It is the mantle of our planet. It is the health and well-being of our children and grandchildren. It is our sacred home. It is our salvation.

Trees offer us the solution to nearly every problem facing humanity today, from defending against drug resistance to halting global temperature rise, and they are eager to share those answers. They do so even when we can’t or won’t hear them. We once knew how to listen. It is a skill we must remember.

Part One

Chapter One

Comfort in a Stone 
My weeping stone sat on the highest shoulder of the valley, where it pointed to the blue above. The stone was way taller than my head, a huge rectangle except for the curve at its crest where chunks had broken loose long ago. Its surface was weathered into rough ripples interrupted by the rounded scabs of lichens. The stone was easily twice the size of the heavy dealwood table in the farmhouse kitchen, big enough that any changes to it occurred on a timeline far too slow for me to perceive, which gave it a welcome constancy.

I called it my weeping stone because I trudged up the hill to be by its side when I felt especially alone. I never really cried. I was beyond tears. Or I repressed my tears, never noticing because I swallowed them whole. I would sit at the stone’s base and lean back against its sturdy flank, ready to slip around to another side and hide if anyone from below called out to me—a reassuring defence, even if no one ever did call.

As I sat there, the slow throb of the Earth settled its calm into my bones. Below me was the farmhouse with its puffs of smoke and, beyond it, the fields of my great-aunt’s farm,each one named in Gaelic like an ancient song. Our neighbours’ farms blanketed both sides of the valley in a patchwork that glowed with a green that seemed to have fire in it. I could watch the seabirds spread open the timothy veil of the pastures and sometimes see the Owvane River, packed with salmon,at the heart of the valley spilling westwards to the open arms of Bantry Bay. If I turned north, I could admire the great sleeping silhouettes of the Caha mountains, colours dancing on their hulking forms. Cnoc Buí—the yellow hill—electrified by its yellow flowers, seemed to vibrate with the chrome of gorse. At times, as I watched the aquamarine of the sea, I wondered about the bolts of bronze that came and went in a silentsymphony of colour. From that vantage point, I could in fact see the entire landscape that had sustained my mother’s family in body and in soul for the past three thousand years. The light playing with the clouds, the salt wind and the rain soothed me.While I never cried buckets up there against my weeping stone,I was a child with no shortage of pain.

On this particular summer day I’m remembering, I had climbed to the stone carrying thoughts of my father. I was an orphan, having recently lost both my parents. I had been lonely most of my young life—separated from most of those around me by nationality, religion and class, just for starters—and I had learned to live with that isolation. But my parents’ deaths struck a blow that I wasn’t sure I could recover from. Months and months had passed and still I felt numb. The daily freshness of their deaths was disorienting, as though the ground and sky had been pulled out from under me. My mourning for my father was constant, the loss so strong that at times I felt winded by its power over me. Some vital part of me was missing and would never come back, because death had closed a door. I just wanted to be small, only a dot, a tiny one. Maybe if I held my breath I could disappear altogether.

I huddled into myself at the base of the stone to survive. The sight of the valley below made me feel both safe and like a tiny dot, as small as the black-and-white cows down there, moving slowly with their pink udders swaying. They were content. I must be, too. And, as I calmed down, I was able to take sober stock of my life.

On my father’s side, I was a descendant of the English aristocracy, the most fragile leaf on a Beresford family tree that included earls, lords and marquises by the branchful. On my mother’s side, I was as Irish as the heather in front of me, the last living drop of a bloodline that could be traced back to the kings of Munster. My dual heritage had inspired resentments, the consequences of which I have borne all my life. As a female child among the Beresfords, I faced the stumbling block of primogeniture. I could not inherit anything of value from my father’s estate other than my bloodline and my name. I was a crossbreed, too Irish for the English and too English for the Irish. My one saving grace in Irish eyes was that I was a femaleand therefore more important than the male. Thoughts that my father’s family would continue to ignore me, as they had since my father’s death, sent me into a panic.But that passed, too, as I looked across the pastures of the Valleyof Lisheens, the handful of square miles of rural Ireland where I would spend my summers for the next decade. I had no inkling yet of the hope that existed right in front of me or of the waysthe land and its people would guide and shape me. I didn’t knowthat the older generation of my mother’s family had already met down at Pearson’s Bridge to discuss my fate. I didn’t knowthat they had already decided to give me the gift of their ancient knowledge, their open secret, and that it would save my life.Or that they intended me to become their “child of destiny.”All I knew, leaning against my weeping stone, was that I was invisible, crushed from too many deaths and utterly alone.

Their takeover was dramatic. In the first years of the 21st century, researchers estimated that bighead carp, one of four Asian carp species now in American waters, comprised 97 percent of the Mississippi River’s biomass. Havana, a hardscrabble Midwest town of 3,000 people in central Illinois, gained minor fame as ground zero for silver carp when their stretch of the Illinois River was found to contain more of the invasive fish per square mile than anywhere else on Earth. In rivers they occupy, Asian carp are often the only fish longer than 16 inches, suggesting many competing native fish fail to reach adulthood.

Within a decade of their introduction in 1963, grass carp spread to 32 states with the enthusiastic support of government agencies, private interests and academia. Silvers and bigheads, introduced in 1972 and sometimes lumped together under the moniker “bigheaded carps,” have moved effortlessly through the Mississippi watershed, following The Big Muddy and its tributary rivers like an interstate highway through the South and Midwest. By 1978, Asian carp had spread 2,800 miles from their port of call in Arkansas, becoming what some believe to be the fastest spreading exotic species in North American history. “Their population exploded,” said Matt O’Hara from the Illinois Department of Natural Resources: “We saw our first fish in the early 1990s. Within a few years, there were fish everywhere.” Steve Butler, a biologist with the Illinois Natural History Survey, tells me he’s witnessed “billions of little, tiny silver carp everywhere” on the Illinois. “As far as the eye can see it was solid spawning carp.” Researchers believe one spawning season can increase silver carp by a billion fish. Or more.

Bigheads strike a prehistoric pose as though forgotten by evolution. Large, wide-set eyes sit low on bulbous heads, their mouths hanging in a perpetual frown. In rare cases, bigheads reach 140 pounds and seven feet in length, though 40 pounds and a length of 28 inches is standard—still big by American freshwater fish standards. Silver carp also sport frowning mouths and scaly heads, heads that are, comparatively speaking, less bulging than the aptly-named bighead. They shade from silver and caramel-colored to olive green and have grown to 100 pounds, though 30 pounds is routine. Both silvers and bigheads share many physiological traits with common carp found in waterways across the continent. Common carp aren’t native per se, but they pre-date anyone currently living, and are often thought of as “naturalized”. This European cousin of Asian carp was first introduced to North America from Europe in the mid-19th century and spread by human hands with unthinkably reckless abandon (imagine tossing live fish from trains into rivers and streams that early transcontinental railways passed by).

The more I scrutinized bigheaded carps the more remarkable I found the functioning of their bodies to be. Both fish are filter feeders that consume throughout the water column. They eat while breathing: it’s a common trait for filter feeders, though in the plankton-rich waters of the Mississippi, it’s proven an especially successful physiological trait. Gill rakers, a crescent of sponge-like cartilage just inside their mouths, usher even the smallest phytoplankton and other organic matter into their gaping maws.

In conversation with Duane Chapman, one of the US Geological Survey’s leading Asian carp experts, he suggests that what sets Asian carp apart from other specialized feeders is their adaptability. “This is an unusual thing,” he says. Specially trained eaters tend to be the best at performing one task particularly well. Think of the sword-billed hummingbird. With its thin beak, longer than its entire body, this South American bird can access nectar stored in a passion flower’s narrow petals that other birds cannot reach. For grass carp, their unique trait is an ability to take water-logged aquatic plants, a low-value food source that few fish eat well and obtain all their nutrients from it. Silver and bighead’s specialized traits are far more dangerous to the health of the Mississippi and Great Lakes’ watersheds. Microscopic organisms are their primary food source, the same phytoplankton that also serve as the predominant nourishment for most of North America’s juvenile (and many of its mature) native fish. Yet when phytoplankton is scarce, native fish will starve while bigheads pivot to target zooplankton and detritus to survive. Silver carp can even live on algae and bacteria. And because Asian carp consume upwards of 20 percent of their weight each day, both species have fundamentally altered the structure of phyto- and zooplankton communities throughout the continent. This may have enormous consequences for species dependent on the resources these invasive fish consume with such voraciousness. Aquatic ecosystems may never be the same as native fishes, and the complex web of predators and prey they interact with, struggle to adapt to life in rivers stolen by Asian carp.

Breeding populations of both species now swim just 76 miles from Lake Michigan, while solitary bigheads have been captured in Chicago’s Lake Calumet, a stone’s throw from the Great Lakes.