In France, the effects of intensive pig farming in Brittany hit the headlines in 2009 when Vincent Petit was exercising his retired racehorse on the beach at Saint-Michel-en-Grève. Without warning he and the horse were sucked into a pit of rotting seaweed up to the horse’s shoulders; the horse died within minutes and Petit lost consciousness. He was saved by a bulldozer operator working nearby who happened to see him go under and dragged him from the hole. For years great heaps of Ulva—the French equivalent of Puget Sound’s sea lettuce—had washed ashore and gathered in piles, liberally fertilized by runoff from pig farms. Sometimes the sun dried their upper surfaces, so they became impermeable lids that trapped poisonous gas below. Petit’s experience raised the profile of marine pollution in France and spurred a municipal cleanup that a few weeks later cost the life of a bulldozer driver who was overwhelmed by hydrogen sulfide. You know things are bad when beaches turn lethal. French authorities have yet to tackle the farm pollution at its source. Until they do, beaches will continue to accumulate stinking seaweed, and the risks it brings.
These stories are shocking but still unusual. Many people remain puzzled by environmental horror stories, because they don’t match their daily experience. If things are going to hell, they say, why does my own life feel like it is getting better? According to the Millennium Ecosystem Assessment, a compendious review of the state of the world environment, they are right.6 Indicators of human well-being are on the rise, even as habitats and species are lost around us. This has been called the environmentalist’s paradox. It helps explain some people’s forthright skepticism of climate change, and why they have concluded not only that it doesn’t exist, but that there is a massive conspiracy among scientists and greenies who peddle this nonsense.
Well-being has certainly improved by several measures: childhood survival, GDP, and level of education have risen steadily the world over, with the exception of sub-Saharan Africa, where they lag badly. These measures don’t capture all of the dimensions of well-being, but where aspects of life such as happiness or gender equality have been measured, they bolster the view that life is getting better for many of us. There is one measure, however, that might give even the most ardent climate skeptics pause, and that is the apparent increase in exposure to natural disasters. Catastrophic floods and landslides are made worse by loss of habitats such as marshland and forest. The impacts of Hurricane Katrina in New Orleans were worse than they would have been had the city not been built on drained marshes that had sunk below sea level. When the levees breached, the city became a brackish lake. But while our exposure to disasters has gone up, our ability to deal with them has too. We are richer and better prepared, so the risk of death from natural catastrophe has gone down globally.
There are several possible explanations for the environmentalist’s paradox. The first is that food is overwhelmingly the key to human well-being, and food production is up. Production of fish, meat, and cereals has outpaced human population growth globally, and health and life expectancy have benefited. (Growth has not been even, and there are many places where rapid soil erosion or water scarcity have triggered famines.) A second explanation for the paradox is that our inventiveness has spared us the adverse consequences of our altered environment. Today, if production falters in one place due to drought or pestilence, we can bring food from somewhere else. Soil erosion and lost fertility can be countered by chemical fertilizers. Fish can be taken from distant seas to fill larders as local stocks decline.
The final possibility is more ominous: We have not yet felt the real cost of our activities but payback is on its way. Prudent financial managers will tell you to spend your profit and not draw down your capital. But for decades now we have been depleting natural resources at an unsustainable rate and literally eating into our assets. Times are still good, but we will feel the impact of our spendthrift ways when our savings run out. Our astonishing population growth is speeding the arrival of that day, although the payback will be in stages, as some resources will run out before others, and people in some places will have to pay sooner rather than later. The hit has come more quickly for a Filipino fisherman than a supermarket customer in the United States, but one day it will happen to us too. We are like debtors living the high life until the moment our creditors force us into bankruptcy.
Already there are credible estimates that suggest we are using something like one and a half planet’s worth of natural resources, based on how much area our present consumption would occupy were extraction and energy use sustainable.7 The only way this overshoot is possible is by living on our savings—in other words, by depleting stocks of natural resources that have built up over thousands or millions of years. Technological innovations and globalization have so far spared the wealthy, but as environmental debts begin to be paid we will all be forced to confront the costs of our lifestyles and those of previous generations. The 2006 Stern Report on the economic costs of climate change, commissioned by the UK government, estimated that there could be two hundred million climate refugees by 2040.8 We can see them already in the tide of refugees that flows to Europe today on the run from drought, famine, flood, and despair in places like Somalia, Sudan, and Pakistan. One widely cited report estimated there were already twenty-five million environmental refugees in the 1990s, and the figure was expected to double by 2010.9
Human relations with the sea have shifted with the passage of time. For tens of thousands of years our ancestors frequented coasts and estuaries, where they hunted and gathered seafood. Close to the places they lived, the remains of shells and fish bones piled up over millennia tell a story of how they reduced the abundance of some species and altered the structure of ecosystems. But their influence was minuscule against the virgin canvas of a measureless ocean. This was the era of carefree use. Humanity neither cared nor needed to worry about what it took from or added to the sea. Ocean resources were limitless against the scale of human need.
From a human perspective, there was a “golden age” of the sea: when people first began to harness the oceans for their own ends at a large scale but before these uses had compromised their abundance and fecundity. This period came in antiquity in the Mediterranean, when commercial fisheries developed for tuna, marine aquaculture was invented, and large-scale ports and harbors were built. The steep growth of our influence in the last few hundred years, and our impact, led people to realize for the first time that their activities could cause problems, like pollution or overfishing. At first those troubles were local and people’s responses, if any, were piecemeal. Often problems such as declining fish catches were ignored or overlooked, as people could still obtain what they needed from further afield. But over time, despite a growing awareness, problems snowballed.
Will we overcome the difficulties we have created? We don’t yet know how matters will play out. I can find reasons to worry and reasons for optimism. There is the enormous scale and accelerating rate of change, the bewildering multiplicity of our impacts, and our inexperience in dealing with global problems that are causes for concern. But there are good reasons for hope. People are ingenious and can rise to challenges; we have found some solutions and can devise others. Thus far, I have focused on the problem. In the remainder of this book I will concentrate on what we can do to improve the state of our seas and keep our ocean planet healthy. What is inescapable is that we must change. Continuing on the present course will lead to an environment that is increasingly hostile, both to aquatic life and to our own well-being.
I am an optimist. What gives me hope is the thought that we have never before had so much raw power with which to solve our problems. Of course it is our power over planetary processes that brought the difficulties in the first place. Nonetheless, it puts us in a different position from our less fortunate predecessors, whose civilizations failed to survive their own transformations of the environment.10 What we do share with past societies is our humanity. We possess qualities honed by the struggle for existence that predispose us to short-s
ighted and selfish behavior. If we can overcome these evolutionary quirks, then a sustainable future may be possible. The Harvard scientist E. O. Wilson has summed up the challenge: “We have Paleolithic emotions, Middle Age institutions, and God-like technologies.” No wonder we struggle to shift from overuse to sustainable uses of natural resources. If we are to survive, we will have to replace our present ways of organizing society, forged over thousands of years, with new means, forged in less than a century. The longer we delay action to reduce stress on sea life, the harder it will become to reverse the unwelcome changes we have unleashed. It is easier to fall into the pit of environmental damnation than to climb back out. The risk is that this backward slide will be tough to reverse. We treasure and love our seas and coasts. They are places to have fun, relax, and go for inspiration. None of these pleasures can be guaranteed, however, unless we recognize and address the dangers now faced by marine life—and, through them, the dangers we face.
How will it feel for our children’s children to live with changes we have imposed upon them? To get an idea of what the future has in store, look no farther than Iceland, with its hardy people scratching a living on a scrap of barren volcanic rock.11 It wasn’t always this bare. When Scandinavian seafarers discovered Iceland they found a country covered in soil, shrubs, and trees. Overgrazing by their livestock destroyed the fragile vegetation, and the soil was lost to the sea, leaving the gray desert we know today. Until a few years ago nobody there realized their island had once been green. But now they can look over the monotonous rocky landscape and into their imaginations, stroll through woodland and heath, and breathe the scent of rowan flowers in spring. If we fail to control climate change and find ways to live that are less demanding of our planet, I doubt that our descendants will so easily forgive us the problems we bequeath to them.
PART 2
Changing Course
CHAPTER 16
Farming the Sea
The sea is inexhaustible, and there can never be a general and simultaneous depopulation. The ocean fisheries will always be copious and easy, and their yield will be greater as the ocean becomes more familiar and the methods employed more perfect.
—Marcel Herubel, French marine biologist1
Marcel Herubel wrote these lines in 1912. He was a gifted thinker. He was well aware that fisheries could be overexploited locally, but like many others of his time, he could not imagine that humanity could ever dent the productivity of oceans on a global scale. Now landings statistics collected by the Food and Agriculture Organization of the United Nations (FAO) show that we have attained the unimaginable. After a thousand years of virtually uninterrupted increase the underlying trend of global wild-fish catches has been down since 1988.2
The picture looks worse if we set fish landings against the explosive growth in human population. Wild fish available per person has fallen by more than a quarter since it peaked in 1970. If fish had been equally available to every citizen of the planet, and all of the catch had been eaten directly—rather than fed to livestock—everyone could have eaten 6.5 ounces of fish per week in 1970; today that has shrunk to 4.75 ounces per week.3
Since at least the early twentieth century, governments have exhorted us to eat more fish to be healthy and slim. Some governments publish guidelines on how much we should eat. New Zealand and Greece think people should eat 17.5 ounces or more per week, while Canada and Austria think 5 ounces is fine. The United States recommends people eat 12 ounces per week. Averaged across the world, we are told we should eat about 9 ounces of fish and shellfish every week, an amount nearly double the availability from wild fish catches. There isn’t enough wild fish to go around.
Ours is an ingenious species, and we love technological fixes. If there are no longer enough wild fish in the sea to feed us, surely it makes sense to farm the oceans? Aquaculture, the production of fish and shellfish in captivity, is a no-brainer. Many now talk of a blue revolution in aquaculture to match the much vaunted green revolution in agriculture. Farmed fish and shellfish already make up around 46 percent of the fish sold for human consumption worldwide.4 So is aquaculture the answer?
Aquaculture has a long history. The earliest representation of fish being kept in ponds was painted on the wall of an Egyptian tomb in the Nile Valley four thousand to forty-five hundred years ago.5 It shows a man seated beside an artificial tank with a central drainage channel, fishing for tilapia with a rod and two hooked lines. Floating plants shelter the fish, while in the background men pick fruit from trees that may have been irrigated by used pond water. Behind the angler, a woman receives the fish.
At about the same time (give or take five hundred years), aquaculture is thought to have developed in China, where freshwater common carp were reared in ponds using fry collected from rivers and lakes. The first manual of fish culture was written in 475 BCE by the Chinese author Fan Li, who is better known today for his popular guide to the rules and pitfalls of doing business. The Chinese refined their methods over the centuries into a sophisticated system of polyculture, raising several other species of carp with different diets, mainly in ponds, but also in rice paddies and lakes. There is a possibly apocryphal story that this diversification was a direct response to an edict by the seventh-century emperor Li Shimin, who declared that nobody was allowed to keep common carp because the fish shared his name. The different species used in polyculture systems eat algae, insects, food waste, and even sewage. They benefit the rice by keeping the mud well aerated and the weeds and pests in check.
In Europe, the Romans, whose appetite for fresh fish is the stuff of legend, took aquaculture to the sea over two thousand years ago.6 Fish ponds were mainly built using a Roman invention, hydraulic concrete, which sets underwater. They have proved incredibly resistant to wave and tide—so much so that many remain intact and almost appear ready to receive fish today. These ponds were not intended to feed the masses. They were expensive to construct and costly to keep stocked. Lucullus, perhaps one of the greatest fish gourmands, reputedly spent more on his fish ponds than he did on his coastal villa.7 He cut a tunnel through a hill to bring water from the sea for his fish.
Roman ponds were remarkably sophisticated. Some were built into dining rooms to form the centerpiece for banquets. Proximity to the fish they ate was important to Romans. For one dish the fish were slaughtered at the table, and guests would enjoy the color changes of the dying animal. Some ponds had viewing platforms, while others had fishing towers from which an angler could pursue his lunch. Many ponds had ceramic pots built into their sides to provide hiding places for eels, which were highly prized at the time. (Some eels were kept as pets and adorned with gold jewelry inserted into body piercings.8) Coastal ponds were often built around natural coves or grottos and were connected to the open sea by channels closed with grates. Waves and tides renewed the water over the tops of the walls and through these grates. Like all previous attempts at aquaculture, Roman fish ponds were really just ranches. Fish were taken from the wild to be stored and grown in captivity, thus ensuring a ready supply no matter what the weather or season.
When Captain Cook first reached Hawaii in 1778 he found an extensive network of several hundred fish ponds.9 Some were enormous, with rock walls over half a mile long, up to seven feet high, and thirty-six feet thick at the base. In Cook’s day, freshwater and marine ponds together supplied the people with an estimated one thousand tons of fish per year. Hawaiian aquaculture is believed to have originated a thousand years ago and contained what might be called an entire ecosystem. Larval and juvenile fish entered through grates that opened to the sea, and grew in size within until they were trapped and periodically harvested.
Necessity has long been a wellspring of creativity. In the Middle Ages, between the eleventh and thirteenth centuries, the avalanche of soil washed off lands newly plowed for agriculture in Europe triggered the crisis in freshwater fish supply that I described in Chapter 2. At the same time, sturgeon, salmon, and whitefish found their migration route
s newly blocked by mill dams. The fall in supply was set against an increase in demand from a larger and more urbanized population. Medieval Europeans had come to value fish more highly due to the spread of Christianity, which prohibited believers from eating the meat of quadrupeds on certain days. The result was the development of pond culture for carp sponsored by monasteries and the aristocracy.
European freshwater carp culture was more sophisticated than Roman sea-fish ranches, because it encompassed the entire life cycle, from egg to adult. It was not until the nineteenth century that efforts began in earnest to close the life cycle of marine fish in captivity. Again, necessity provided the impetus. Salmon runs in European rivers had for centuries been in private ownership, with fishing rights mainly reserved for the aristocracy. The Industrial Revolution caused many of those rivers to become so polluted and blocked by dams that salmon numbers plummeted. Fish hatcheries were established and salmon were stripped of their spawn in captivity and their offspring raised to fingerling size before being released into rivers to complete their life cycle in the wild. The growing sophistication of these efforts is attested to by the fact that from 1868 until the early twentieth century salmon and brown trout eggs were taken by ship to New Zealand for release into rivers and lakes for the sport and sustenance of expatriate Brits.10 Brown trout got going quickly, but the salmon was troublesome, eventually establishing in the watershed of only one river.
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