Looking Into the Abyss – Part One

5/27/21

May 28, 2021

There’s a literary one-liner that’s been on my mind lately. Phrased differently through the centuries, and used by everyone from Blaise Pascal to Mark Twain, it goes something like this: “If I had more time, I would have written you a shorter letter.” (Woodrow Wilson joked that it took him two weeks to write a ten-minute speech, but for a two-hour speech he was ready now.) This week again I find myself deep into a word-count on a topic that requires far more words but which is written for an audience that deserves complexity married to brevity. My solution, again, is to split the writing up, this time into two parts. The topic this week (and next) is the state of the oceans.

“Who has known the ocean?” asked Rachel Carson in her 1937 essay “Undersea.” “Neither you nor I, with our earth-bound senses, know the foam and surge of the tide that beats over the crab hiding under the seaweed of his tide-pool home.” Carson, a poet/scientist of the sea long before she became known for Silent Spring, noted that the mysteries only deepened with distance from land, amid “the lilt of the long, slow swells of mid-ocean, where shoals of wandering fish prey and are preyed upon, and the dolphin breaks the waves to breathe the upper atmosphere.”

And deepened with depth as well: “Fishes and plankton, whales and squids, birds and sea turtles, are all linked by unbreakable ties to certain kinds of water,” she wrote, but piercing the watery veil was difficult: “Whales suddenly appear off the slopes of the coastal banks where the swarms of shrimplike krill are spawning, the whales having come from no one knows where, by no one knows what route.”

Eighty-four years later, so much more is known, with each day bringing another cache of data from the sea. Observations are made by ship and satellite, by buoy and trawler, by multidisciplinary and multinational research teams in labs on every continent. The paths of Carson’s whales are better known, as are the songs they sing upon them. The intricate traceries of plankton are better understood, as are their chemical signatures which attract pelagic seabirds to mid-ocean meals. Each of these subjects, and ten thousand more, now have their place in the vast library of the science of the sea. And yet, as quickly as this new knowledge is gained, so much of the living ocean is being transformed or lost.

The state of the oceans is abysmal, from the tide pool to the abyss.

But for most of us both of these processes – the knowledge gained, and the life lost – are invisible. We stand on the shoreline and – notwithstanding the plastic trash at our feet – fall in love with the beautiful sea. Very few of us are marine scientists or fishermen or blue-water sailors, while even fewer sink below the surface of deep water. When we do, either in person or virtually, it’s a revelation. As Dave Barry put it, “when you finally see what goes on underwater, you realize that you've been missing the whole point of the ocean. Staying on the surface all the time is like going to the circus and staring at the outside of the tent.”

Inside the tent, a quick survey of our actions and their impacts, especially impacts predicted for the end of this century, is shocking. Not a surprise, I guess, when you add the “deadly trio” of ocean warming, acidification, and deoxygenation to the old-fashioned threats of overfishing, habitat destruction, and pollution. But it’s still shocking. Particularly when you learn that much of this bad-news portrait of the state of the oceans looks a hell of a lot like the precursors to the five previous mass extinctions.

Let’s start with overfishing, which offers the closest thing to good-news in this litany. It’s worth noting first that “exploitation” is not a dirty word in fisheries science; it’s the word for how much of a given species is being removed from its population. According to the UN Food and Agriculture Organization, about 34% of fisheries are overfished, constituting about 23% of seafood brought to market. And a 2020 study of managed fisheries around the globe indicates that where fisheries are intensively managed, exploited stocks are at sustainable levels or rebuilding toward that level. Less actively managed fisheries have triple the harvest rate and half the abundance, while unmanaged fisheries suffer from widespread overfishing. Here’s a UN FAO graphic:

Sadly, though, as much as the study is a vote of confidence for scientific management, the authors admit up front that only half the global fish catch occurs under such supervision. If the other half of the global catch comes from illegal fisheries or from the waters of nations unable or unwilling to set catch limits and enforce those limits, then there are a lot of fish populations that will continue to decline as exploitation pressure (along with human population) increases and other Anthropocene ocean stressors come into play. Also, one of the side effects of tight management in some countries is increased pressure – legal and illegal – on less regulated waters.

I am at least heartened by the general success of serious management. Any increasing wild abundance – as is happening with many whale populations – in the 21st century is remarkable. As I noted back in my very first post, referencing my father’s work, fishery exploitation management might not be love, but it is a form of respect. Applied to all our relations with other species, respect would get us a hell of a long way toward a sustainable life on Earth. Let’s hope that the dark half of fisheries finds some conscientious managers soon.

As with overexploitation, habitat loss involves many factors, including warming and acidification and deoxygenation, but the standard troubling big picture has two separate parts: the destruction of broad swathes of ocean floor from decades of bottom trawling, and the loss of crucial complex habitats such as coral reefs, mangrove forests, and kelp forests. Bottom trawling is remarkably effective, but scrapes up everything like a bulldozer at a pie-eating contest. “The whole bottom becomes a wasteland,” says a researcher with Sea Around Us, whose 2018 study showed that only a third of what was pulled up during a half-century of bottom trawling was officially documented. The two-thirds left out were non-commercial species that were either unofficially sold or simply tossed overboard to live or die amid the rubble of their habitat.

90% of California kelp forests are gone, reflecting trends in many places around the globe. Like everything else in the oceans, kelp forests are threatened by the “deadly trio” (especially warming waters), but their disappearance so far is largely due to an explosion in sea urchin populations, which occurs most often because we overharvest urchins’ predators, such as sea otters in California and lobsters in Australia. The really bad news about this is that kelp forests are incredibly important habitats for biodiversity, and that once the urchins have stripped the forest down to nothing, they will prevent it (and anything else) from ever growing back. The lush kelp forest becomes a desert. No one has ever seen an “urchin barren” recover, even after several decades.

Mangrove forests, essential to healthy coastal ecosystems in much of the world, work as a breeding ground and nursery for hundreds of fish species, support hundreds of bird species (not to mention monkeys, dugongs, turtles, and lizards), protect coastlines, and filter sediments that would harm coral reefs. Yet 30% to 50% have been lost in the last fifty years due to shrimp farming, agriculture (palm oil plantations, rice paddies, etc.), overharvesting, and development. Restoration projects are happening, but are small-scale so far.

The threats to coral reefs are well-known – warming and acidification mainly, plus pollution, physical damage, and overfishing of key reef species – and the prospects for corals surviving in any meaningful way appear faint. One prediction is for 90% of the world’s corals to die by 2050, while the UN Environment Program expects a total loss by the end of the century if we don’t constrain rising temperatures. Already the Great Barrier Reef has lost half its corals since 1995. In a world without reefs, 25% of fish species would lose key food, shelter, and spawning grounds. Ocean biodiversity would plummet (assuming it hadn’t already because of other effects of the warming ocean), collapsing many human fisheries in the process. According to the UN, a billion people rely on coral reefs for food and livelihoods.

The corals of yesterday, today, and tomorrow - The Ocean Agency

The usual suspects in ocean pollution are oil spills, chemical contamination (from both marine and land-based sources), nutrient runoff (I’ll write about this in the section on deoxygenation), marine debris (esp. plastics), and noise from shipping and military sources. One little-known 2004 oil spill, perhaps equal to the notorious BP Horizon spill (but with none of its publicity), came from a wellhead in the northern Gulf of Mexico ruptured by an underwater avalanche. It gushed oil for sixteen years until it was finally capped in 2019. The oil and gas industries regularly spew toxic by-products into the oceans, as do we, from our lawns and sewer systems and coastal industries. Some of these chemicals, like PCBs, endure in the environment and continue to cause harm, particularly to marine mammals. A 2016 study of European cetaceans showed that two thirds of the dolphins and orcas they sampled had “mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds,” despite a ban on PCBs in Europe back in the 1980s. This can lead to, as they called it, “PCB-induced reproductive toxicity,” which might explain the struggles of these species to rebuild their populations.

But the big marine pollution story these days is all about plastics. Rachel Carson’s crab is awash in the foam and surge of microplastics and nanoplastics. The entire ocean is contaminated with plastics, from the tide pool to the deepest abyss to remote Antarctic waters. Eight million metric tons of plastic reaches the ocean every year. The Ellen MacArthur Foundation made news in 2016 predicting that (by weight) there will be more plastic than fish in the ocean by 2050. It’s not a verifiable estimate, but it was valuable simply by asking if that might happen. Plastics have infiltrated and toxified the entire oceanic food chain, from plankton to marine mammals to the flesh of the fish we eat. The damage is far too multifaceted to explore here, but the categories of harm range from physical (obstructing the digestive systems of everything from microbes to albatrosses) to biogeochemical (decreasing oxygen in the oceans because zooplankton dine on microplastics instead of phytoplankton). And while plastics threaten ocean chemistry and the entire food chain, the story that sticks in my craw is this: Some pelagic seabirds, those exquisite, gloriously evolved creatures soaring and navigating the wild open ocean, are now filling their stomachs with plastics because the debris, after marinating in the sea for months or years, smells just like the zooplankton they’ve dined on for millennia.

[Okay, that’s this week’s half. It’s rough, I know. Thanks for sticking with me. Next week we’ll get to the “deadly trio” and to the disturbing connections between the ocean of tomorrow and Earth’s previous mass extinctions.]

Finally, for today: Peruvian poet and fisherman Freddy Guardia learned from a lifetime on the sea about the uncertainty of existence. Just as the surface of the sea never rests, the world around us is in flux: “Nothing stays the way you want it to,” he says in the lovely short documentary The Ceviche Fisherman, “that’s why we have memories.” But what are our memories of the ocean – the real ocean, in its depth and distance and complexity – when we’ve spent our lives looking at the outside of the tent? And what good are memories anyway when, in the Anthropocene, the ocean is not merely in flux but in trouble?

Field Guide to the Anthropocene

Discussion about this post