When Grant Downey left the Pacific for about 10 minutes, he realized that he could no longer see anything with his right eye.
This second-generation commercial diver looked for his catch deeper than usual under the waves-red sea urchins are cherished by restaurant owners. University, Or sushi-grade gonads. But in recent years, red sea urchins living in underwater seaweed forests have become increasingly difficult to find. Each additional foot of depth forces more nitrogen into his blood, increasing the risk of dangerous bubbles in his body or brain.
This time, half of his sight was on the black wall, and he worried that he had finally pushed his body too far. Although his right eye regained function after 20 minutes, the 33-year-old decided to complete this adventurous dive, even if this decision would eventually cost him his income.
“I know this is what it is for me,” Downey said in March last year, about seven months after the incident happened off the coast of Fort Bragg, Northern California. “I might go down to 65 feet, but I don’t know if I will go that deep, so deep. For those players who are still trying to go, it’s getting harder and harder.”
Anyone who depends on California’s seaweed forests for their livelihoods can tell you that the conditions below the surface of the Pacific Ocean are terrible. It’s not just red sea urchins that are declining. Most of the kelp has disappeared. The dense autumnal seaweed once provided food, shelter and safe haven for hundreds of marine species-from sea otters to abalones, from rock fish to crisp stars. The dense giant kelp or whip-like high kelp once swayed, and the entire underwater forest was razed to the ground by a special predator-purple sea urchin.
People sometimes call purple sea urchins “zombies” in the ocean-this is the result of their huge hunger and powerful survival skills. (They can survive in “hunger” mode for many years.) Similar to baseball-sized spiked pompoms, purple sea urchins are omnivorous and eat everything from plankton to dead fish. But they especially like kelp. They can chew on the fixture that holds each kelp to the bottom of the sea.
The resulting “sea urchin wasteland”, as divers said, can stretch for hundreds of miles. Scientists reported earlier this year that some seaweed forests in Northern California suffered 95% loss since 2012.
Kelp is the key to most of the marine biodiversity on the west coast. Like terrestrial forests, kelp (technically a brown algae) is an important carbon sink, converting sunlight and carbon dioxide into leaves and canopy.But unlike trees, they emit most of their carbon into the atmosphere when they decompose. The Dead Sea Belt with potential Sinking into the sea floor provides a natural form of isolation. As the seaweed forest was razed to the ground, sea urchins were starved to death and waited on the bottom of the sea, this cycle has been severely disrupted.
“We are losing very important systems, which means losing fisheries, losing recreational opportunities, losing carbon storage, losing coastal protection,” said Fiorenza Mikkeli, a marine ecologist and co-director of the Stanford Ocean Solutions Center. “This is basically the equivalent of losing the rainforest-unless we don’t see it.”
I’ve seen parts of the west coast Increase by 10,000% Among the purple sea urchins during the five-year period. As commercial divers called it, a large number of “purps” shook communities along the southern coast of California and Oregon. As a result, many kelp enthusiasts—commercial fishermen, recreational enthusiasts, scuba divers, and scientists, to name a few—are increasingly eager to take the purple sea urchin infection in their own hands, usually holding hammers and diving knives.