The ocean can be a lonely place. Ivan MacFadyen expected long weeks of isolation when in March he set sail from Melbourne to race his yacht to Japan, and then on to San Francisco. Having completed the same race 10 years earlier, he expected the company of other ocean travellers. “I’ve done a lot of miles on the ocean in my life and I’m used to seeing turtles, dolphins, sharks and big flurries of feeding birds. But this time, for 3,000 nautical miles there was nothing alive to be seen,” he said. Only the clatter of rigging and slap of water broke the monotony.
MacFadyen’s experience could hardly be more different from the French explorer La Pérouse’s crossing of the Pacific in 1787. Near the equator, he wrote that terns “flew in such numbers around our ships, especially during the night, that we were deafened by their noise and it was difficult to hold a conversation on the upper deck, so that our fairly successful hunts provided us with some revenge for their screeching”.
Comparisons are hard to make across the centuries, but the logs of other 18th-century sailors relate similar tales of abundance, such as that of the English navigator George Shelvocke in 1726: “Whales… and other fish of a monstrous bulk, are in such numbers off the coast of Patagonia that they were really offensive to us very often. For they would come sometimes so close to us as to stifle us with their stench when they blew, and would lie so near us that I have frequently thought it impossible to escape striking upon them on every send of a sea.”
My student Annie Murray has extracted records from such logs and contrasted them with encounters by modern adventurers, trans-oceanic rowers such as Roz Savage. Rowers have the time to observe life, but they reported only half the variety spotted by sailors of old, and the numbers of animals seen at a time could usually be counted on the fingers of two hands, as opposed to tens, hundreds or thousands.
MacFadyen blames overfishing for the dearth of life. Seabirds and tuna might seem unlikely allies, but birds depend on them to drive prey within reach. If big predatory fish disappear, so do birds, and our insatiable appetite for tuna has driven down stocks to the point where birds are also dwindling. Terns dance on the waves as they pluck prey from the surface, so it is hardly surprising they have suffered big losses. In other places, industrial fishing targets forage fish – species such as herring and pilchards that support prolific foodwebs – to the point of collapse. Penguin colonies in Namibia have fallen silent as nearby waters have been stripped of the fish they depended upon.
What rowers did see that 18th-century explorers did not was the flotsam and jetsam of modern life. Plastics were pervasive. One poignant moment for Mick Dawson and Chris Martin as they pulled themselves across the North Pacific came when they found an Albatross closely guarding a rubber ball. They were passing through the midst of a giant circulating current that concentrates floating trash in “the Great Pacific Garbage patch”. In a heartbreaking mismatch of ancient instinct with modernity, Laysan albatross cannot distinguish floating plastic from food. They scour thousands of miles of ocean to bring home “junk” food for their young. Chicks starve with full bellies and when their bodies rot away, they leave tragic piles of bottle tops, pens, cigarette lighters and plastic fragments to bleach in the sun.
Tangled junk rafts snare bigger victims. I saw a photograph of a turtle dragging a ball of fishing net 20 times its size. Condemned to pull its burden through the sea, its life seemed as hopeless as that of Sisyphus, forced to roll a rock uphill only to have it roll down time and again.
Near Hawaii, MacFadyen ran across the horrifying legacy of the Japanese tsunami which thickened the Pacific soup of debris when it launched the remains of coastal towns into the ocean. Lumps of debris as large as houses and countless wooden power poles trailing wire mingled with thousands of fishing floats and millions of pieces of polystyrene.
MacFadyen’s pitiful voyage is emblematic of our reckless disregard for the ocean. For centuries we have treated it as endless and bottomless; a place that gives forth riches and swallows waste. But with more and more of us crowding the planet, we have gained the ability to destroy before finding the wisdom to exercise restraint. We depend utterly on the sea for life, not just in the sense of food, but for its role in keeping our world habitable. This year a high level Global Ocean Commission has been convened to consider what can be done to turn the tide. For the sake of all of us, let’s hope the world’s leaders listen and act when it reports next year.
Callum Roberts is Professor of Marine Conservation at the University of York. 'Ocean of Life: How Our Seas are Changing’ (Penguin) is shortlisted for the Royal Society Winton Prize for Science Books.