The leafy sea canopies of the Pacific Ocean’s bull kelp forests are largely gone, as a new paper in the journal Nature lays out in terrifying detail. But just because this emergency is out of sight and under the waves doesn’t make it any less vital.
This catastrophe has played out in stages. First, the kelp forests were hit in 2014 with an abnormally intense marine heat wave — the longest on record. This created nutrient-poor conditions that suppressed the kelp’s spore production.
Then came a plague of purple sea urchins, which feed on kelp. Normally, urchin populations are kept at bay by their main predator, the sunflower sea star. But a disease that proliferates in warm temperatures wiped out the region’s starfish populations. Within a year of the disease being detected in 2014, most starfish disappeared, and the purple sea urchins multiplied 60-fold.
By the time the urchins were done with these green oceanic pastures — which stretched more than 200 miles along California’s coast — they had been reduced by more than 90 percent, throwing the ecosystem into disarray. Red abalone sea snails, which also eat kelp, starved en masse as the urchin populations exploded. Meanwhile, fish species that use the kelp as nurseries fled. Elsewhere on the Pacific Coast, fish-eating species such as bald eagles and harbor seals had to look for different sources of food.
If you find it difficult to care about wildlife and kelp forests, there’s a human angle, too. Because of the ecological disaster, California was forced to close the commercial abalone fishery last year, worth upward of $44 million a year. Many recreational fishing businesses have yet to recover; some are likely to close.
There’s an effort underway to try to turn the urchin explosion into a commercial venture, but it’s not without challenges. The urchins, which can live for decades without food, have eaten through most of their ecosystem, so they’re now starving. As a result, the edible portion of urchins — called uni — are depleted and commercially worthless. To make them worthwhile, fishermen would need to capture them and nurse them to health with algae.
Meanwhile, scientists warn that kelp recovery remains a long way off. And although most starfish species are slowly coming back, California scientists fear that the sunflower sea star may be locally extinct.
“We haven’t seen one in years now,” said Laura Rogers-Bennett, co-author of the Nature study and a researcher at the Bodega Marine Laboratory at the University of California at Davis.
Die-offs such as these don’t usually attract wall-to-wall coverage from the media. Compared with wildfires and hurricanes, they are slow-motion disasters.
But while wildlife populations are supposed to be resilient to shocks in their ecosystems, catastrophic events such as heat waves and major storms are happening on such large scales and so frequently that many species can’t recover. Scientists are already forecasting another major marine heat wave to hit the Pacific Coast this winter.
These disasters are happening everywhere: One of the largest emperor penguin colonies in Antarctica collapsed this year after a storm destroyed the sea ice its chicks depended upon. In the Mojave Desert, bird populations have plummeted as they have failed to cope with hotter and drier weather. Off the coast of Australia, back-to-back bleaching events in the Great Barrier Reef led to a collapse of new corals last year, making the reef’s recovery less likely.
If you think such collapses don’t affect you, think again. Climate change, along with habitat destruction and overconsumption, is eviscerating species that are crucially important to humans. Most insect species are either declining or endangered. Over the past half-century, North America lost a quarter of its bird populations. These are the pollinators, seed distributors and food chain managers that are essential to life on Earth — and, by extension, human civilization.
The media does the public a disservice by almost exclusively focusing on climate change when extreme weather directly threatens people. And even when climate change does take up our news feeds, it seems that the public has become largely numb to the crisis. But climate change never takes a pause; humanity’s excesses endanger Earth’s biodiversity. It’s time we recognized that we’re putting ourselves at risk as well.