The Ocean of Life

by Callum Roberts

  The thing about marine mammals that disturbs me is that they aren’t very different from us. Early on in this book I raised the possibility that modern humans long ago developed adaptations to accommodate a semiaquatic life, such as the fact that we have a body fat content similar to fin whales. (Actually, given the rise in obesity, some of us now rival seals and walrus!) All that fat predisposes us to concentrate a nasty cocktail of pollutants, just like the dolphin, the seal, and the whale. And like Sarasota dolphins we can pass them to our children in utero and through breast milk. I once told a lady I met at a conference the story of how first-born dolphin calves receive most of the chemical load carried by their mothers. She said, “You know, that explains so much about my older brother!” Joking aside, these toxins could lead to all kinds of problems in later life, from learning difficulties to cancer.17

  PCBs, together with a variety of other industrial chemicals, including heavy metals, are hormone mimics that can interfere with the regulation of development and other bodily functions. Highly contaminated animals can therefore be sterilized by these “endocrine disruptors,” as they are called, or their offspring affected in subtle and insidious ways. It takes only tiny traces to alter our hormone systems in ways that are detrimental to the health of us and our babies.

  Indigenous peoples in the far north often carry heavy loads of toxins in their bodies. This is not because Arctic regions are more contaminated than lower latitudes; actually, they are less so. It is because of what people eat. Traditional diets often contain a great deal of blubber from marine mammals, exactly the food you would want to avoid to minimize exposure to toxins. The most contaminated flesh comes from animals that feed high in the food chain, like narwhal and beluga.18 Animals like bowhead whales, which are still hunted traditionally on Alaska’s North Slope, feed lower down the food web, and their flesh is safer. The highest levels of PCBs, DDT, and other contaminants are found in the Inuit of Greenland. Tests of the mental abilities of children in some Arctic communities have revealed that those who come from mothers with high toxin loads were more likely to have problems, a pattern also found in children from industrialized countries. PCBs and other hormone mimics depress the production of thyroid hormones critical to fetal brain development.19 Such relationships in the United States and Europe have led people to ask whether our increasingly contaminated world is the cause of the rising incidence of conditions such as autism and attention deficit disorders in children. The Arctic Council, an intergovernmental body that oversees the interests of Arctic peoples, recommends that women there continue to breast-feed their children, because they reckon the health benefits still outweigh the possible harm done by pollutants.20 But it is a close call.

  The good news is that time has been called on PCBs in much of the world. The United States banned them in 1976, and many other countries have followed. The Stockholm Convention on Persistent Organic Pollutants, which was drafted in 2001, prohibits the manufacture or use of a suite of problem chemicals (but, incredibly, DDT is still permitted for pest control in some developing countries). By 2008, 153 countries had agreed to abide by the terms of the Stockholm Convention (fortunately including big emerging polluters like India, China, and Brazil). The PCBs and similar toxins already at large in the sea will cause problems for decades to come, as their release continues from the breakdown of contaminated waste and fixtures in buildings, but levels are falling gradually as they slowly degrade to less harmful chemicals. A survey of the Arctic between 2001 and 2008 found that surface waters contain in total less than half a ton of PCBs, just one thousandth of 1 percent of the world production of these chemicals. Levels in seabed sediments were not tested, and toxins there could keep coming back as they leach from sediments, are resuspended by bottom trawls, or are released by the crumbling remains of contaminated waste.

  Heavy metals like copper, lead, zinc, and mercury also contaminate the oceans and have proven far more difficult to control than PCBs. One of the most toxic is methyl mercury, because it is easily absorbed and can cross the blood-brain barrier. Much of the mercury we are exposed to today comes from emissions by coal-fired power stations that countries seem hell-bent on building more of, despite their contribution to global warming. Asian power stations produce over half of the world’s mercury pollution, and much of it blows straight over the Pacific, where it combines with particles of organic matter and is converted to methyl mercury by microbes.21 Mercury concentrations in the Pacific have increased by 1 percent to 3 percent per year in recent decades. Mercury is highly poisonous and accumulates through food webs, so top predators like dolphins, tuna, and swordfish can be heavily contaminated. Tests on Pacific black-footed albatross feathers from museum specimens collected between 1880 and 2002 show an increasing burden of methyl mercury over time, with a surge after 1990, mirroring the growth of the Chinese economy.22

  Like POPs, heavy metals can act as hormone mimics that disrupt the endocrine system. A much-publicized study of white ibises in Florida found that methyl mercury causes male birds to pair up with other males.23 It was a gift to headline writers: POLLUTION TURNS BIRDS GAY! White ibises feed in the marshes of south Florida, stalking through the swamp picking up animals such as frogs and insects with their slender, curved bills. Scientists took birds from wild ibis colonies and fed some uncontaminated food and others a diet laced with methyl mercury at concentrations found in the wild. Male birds given mercury-tainted food were less attractive to females, and up to half of them ended up building nests with other males. Not surprisingly, mercury contamination reduced the number of chicks fledged by a third.

  Canned tuna is virtually ubiquitous, and the wealthy world has developed a passion for sushi, which is where many of us pick up our mercury. (One estimate suggests 40 percent of bodily mercury in Americans comes from tuna.)24 Mercury in tuna sampled from restaurants and fish markets regularly exceed levels considered harmful by the World Health Organization. Large tunas, such as bigeye and bluefin, are worst affected, so perhaps it is a good thing that bluefin tuna is far too expensive to be eaten in anything other than sliver-size portions!25 Samples of swordfish from California supermarkets were on average one and a half times above federal guidelines for mercury consumption. While there are obvious health benefits from eating fish, the U.S. Food and Drug Administration is so concerned about the problem it advises pregnant women and children, who are more at risk of harm, not to eat shark, swordfish, king mackerel, and tilefish (a bottom-living fish common off the Carolinas).26

  Another notorious hormone mimic is tributyltin, which was widely applied to ships’ hulls in the 1970s and 1980s as an antifouling compound. Female dog whelks—a type of snail—grew penises when exposed to this compound; oysters developed shell deformities; and some shellfisheries near ports and marinas collapsed. The International Maritime Organization imposed a global ban in 2008 in recognition of its potent toxicity. But there are many other chemicals that remain unregulated.

  Despite efforts to rid the world of persistent chemical toxins, our environment isn’t getting cleaner—in fact, just the opposite. Chemical industries are constantly creating new products, and phasing out one leads to demand for substitutes. There are about 8.4 million commercially available substances worldwide. Over thirty thousand organic chemicals are produced by industry in quantities bigger than a ton a year, and most have never been formally tested for toxicity.27 The majority probably pose little risk, but the trouble is we don’t find the ones that do until they have been in circulation for years.

  Another group of chemicals—brominated flame retardants, or BFRs—was drafted in from around the 1970s to replace some of the roles filled by PCBs.28 They have found their way into every sphere of modern life. They are slathered over our furniture and packed into circuit boards and plastics used in consumer electronics. Clothes made of artificial fibers are steeped in them, and they are in plastic food packaging and Styrofoam cups. Many governments demand high standards of fire prevention and compel manufacturers to use
the best chemicals for the job. BFRs can make up a quarter of the weight of plastic in electronic goods and foam fillers of furniture. Although less toxic than PCBs, BFRs share their propensity to build up in our bodies and concentrate their way up food chains. Mothers pass them to their children during pregnancy and breast-feeding. Just like PCBs, they also seem to be endocrine disruptors that can interfere with child brain development.29 There is now much anxiety about their safety, and some countries, like Canada, have already banned the most pernicious compounds.

  Pharmaceuticals are an emerging class of pollutants that is racing up the ranks of chemicals to worry about.30 Throughout the world human populations are growing, aging, and increasingly dosing themselves with drugs to combat health problems. Lax controls on pharmaceutical manufacturers in developing countries mean there is an increased potential for release into the environment. Pharmaceuticals are designed to have large biological effects at very low concentrations and, like PCBs, some of them accumulate as they work their way up through the food web. Many are excreted and remain stable in the environment for long periods, during which they can cause considerable mischief. Given the many unexplained declines in wildlife around the world, attention is turning to whether trace contaminants like these could be responsible.

  There is little in the way of research on marine life so far, but freshwater species have been better studied. Downstream of sewage treatment works, male fish have been feminized by synthetic estrogen from contraceptive pills and hormone replacement therapy. Ibuprofen, a common anti-inflammatory, reduced reproduction of freshwater fleas in a lab experiment.31 The good news is that lab tests often produce effects only at higher chemical concentrations than are normally seen in the environment. The bad news is that subtle effects may only manifest themselves over the long term. Many drugs, like antidepressants, are designed to affect mood and behavior. Fluoxetine, the active ingredient of Prozac, can cause symptoms in fish such as erratic swimming, unresponsiveness, and decreased aggression and feeding.32 Happy shrimps live dangerously, according to another study, swimming away from shelter and into the waiting jaws of predators. Any of these effects could potentially disrupt the life cycle, increase mortality, or reduce breeding success.

  Another class of emerging pollutants are nanoparticles, extremely small particles billionths of a meter across that are used to make better cooking oils, improve the efficiency of solar panels, and enhance the drug absorption of pharmaceuticals, among almost countless other possibilities in the pipeline. One familiar use is of silver particles incorporated as antibacterials in underwear and socks. By virtue of their size they can easily pass into emissions and become incorporated into body cells. Research is still in its infancy, but there is evidence that such minute particles can do more damage than larger particles of the same substances.33 There is currently enormous investment in research and development of nanotechnologies but much less in exploring their possible environmental effects. We should be concerned that this revolution in materials science doesn’t outpace caution. For example, filter-feeding mussels exposed to nanoparticles in glass wool developed to clean up oil spills accumulated particles in their gills and vital organs, where they caused cell damage and death.34 Scientists are diligently trying to engineer nanoparticle-sized pesticides to increase their potency. Although this may decrease the quantities that will need to be applied, the potential for new damage is already clear.

  I don’t want to leave the impression that the oceans are toxic. In much of the sea, especially far from human habitation, pollution is very low. Dangerous chemicals are concentrated where inputs are high, around estuaries and cities, ports, and shipping lanes. Only a few places are contaminated enough to be dangerous, like New Bedford Harbor in Massachusetts. This site received industrial wastes for so many years that sediments there are loaded with a cocktail of chemical nasties. Fishing is banned and a cleanup is underway to remove contaminated mud. The wider problem is that chemicals concentrate from trace amounts in the water to harmful levels in animals. Tens of thousands of tons of flame retardants are produced per year, and they are already well embedded within marine food webs. Tissue samples taken from a group of false killer whales around the main Hawaiian islands contained high levels of flame retardants, while southern California sea lions had levels forty-five times higher still.35 The bodies of both species were also laden with PCBs and DDT.

  It is easy to be indignant about the ubiquity of chemical pollution and to rail at the rapacious corporations that peddle these products. But we shouldn’t forget the thousands of lives they save. Flame retardants have spared many people from being torched in their beds and DDT has prevented countless deaths from malaria. But a balance must be struck between safety and danger. Once chemicals get into the sea it is very difficult to remove them. And we have only recently begun to realize that toxins such as mercury and PCBs combine with another kind of waste that is on the increase in the world’s oceans: plastic.

  CHAPTER 10

  The Age of Plastic

  One tempestuous night in 1992 a container ship from China ran into heavy seas in the western Pacific. Huge swells breaking over the ship washed a containerload of plastic bath toys overboard. This set some twenty-nine thousand plastic ducks, turtles, beavers, and frogs free on a voyage that for some has not yet ended. When bath toys began to appear on North American beaches, Curtis Ebbesmeyer, a Seattle-based oceanographer, latched onto the importance of this event as a way to track the movements of the great ocean currents.1 The toys hitched rides on several currents circling the Pacific, and over the years have made landfall in Hawaii, Alaska, and Washington State. Some even threaded their way through the Bering Strait into the Arctic Ocean, where they froze into pack ice. That ice then bumped and scraped its way around the pole, pushed by winds and underlying currents, before it disgorged the toys into the North Atlantic. These travelers have since been picked up on beaches in Maine and Scotland.

  More than two millennia have passed since the great philosopher and naturalist Aristotle walked the shores of the Mediterranean island of Lesbos, deep in contemplation. It was on Lesbos that he laid the foundations for his masterwork of natural history, whose influence would endure until the Age of Enlightenment. Those beaches would have been strewn with natural flotsam, the strandline drawn in palm fronds, seaweed, and seeds. Here and there a fragment of worn plank or the sole of a leather shoe or decayed rope would betray the work of man. Fast-forward to a hundred years ago, and beaches had by this time become littered with the flotsam and jetsam of human societies, but the main difference from Aristotle’s time was the quantity rather than the type of rubbish. Fragments of nets, strands of hemp rope, and storm-shattered wooden boat spars would still be there, but this time with glass fishing floats, barrel staves, and bigger heaps of rotting organic refuse carried to sea by rivers. Today a beachcomber is faced with a very different kind of garbage.

  Archaeologists excavating the remains of our world two thousand years from now will call this the Age of Plastic. Victor Yarsley, an English chemist, helped usher it in. Yarsley was born in 1901, and early on became interested in the industrial potential of synthetic polymers. He spent his early career trying to develop nonflammable celluloid film, but he eventually abandoned the search, declaring it impossible. He then struggled for decades to find ways to realize the potential of plastics, working long hours from a lab jerry-built in his garden shed. His daughter later recalled having to tape over holes and cracks in her bedroom to keep out the awful smells.2 Success eventually came when he discovered ways to make plastics without air bubbles and perfected mixtures for new products such as dentures and prosthetic limbs. By 1941 Yarsley felt confident enough to set down his vision for a future world built around the miracle of plastic:

  This plastic man will come into a world of color and bright shining surfaces where childish hands find nothing to break, no sharp edges, or corners to cut or graze, no crevices to harbor dirt or germs.… The walls of his nursery, his bath,…
all his toys, his cot, the molded light perambulator in which he takes the air, the teething ring he bites, the unbreakable bottle he feeds from. As he grows he cleans his teeth and brushes his hair with plastic brushes, clothes himself within plastic clothes, writes his first lesson with a plastic pen and does his lesson in a book bound with plastic. The windows of his school curtained with plastic cloth entirely grease- and dirt-proof… and the frames, like those of his house are of molded plastic, light and easy to open never requiring any paint.3

  Predictions about life in the future are often funny and usually wildly off. According to the books I read as a ten-year-old, by now we should all be skimming the skies in airborne cars and relaxing in the garden as robots cook our dinner and clean the house. What is remarkable about Yarsley’s world is that it has come true, and we are living it. By 2008, the latest year for which I have a figure, 286 million tons of plastics were produced using 8 percent of global oil production in raw materials and energy.4 The curve of production over time bends upward like a cliff face, increasing by 9 percent per year. The stark reality of this ever-steepening upward climb is that more plastic was made in the first ten years of this century than all of the plastic created in history up to the year 2000. The world is awash with plastic—most of us are rarely out of contact with something made of the stuff. We are literally and figuratively swimming in it. But Yarsley’s powers of foresight deserted him on one key matter. His future was a brighter and better world: