ON THE COVER
Tools in the Toolbox
Looking for ways to restore and protect the state’s beleaguered bull kelp forests and in turn, red abalone stock By Kimberly Wear kim@northcoastjournal.com
T
he fragile future of the North Coast’s beleaguered bull kelp forests is perhaps best captured in a single photograph taken off the Mendocino County coast last summer. The image is at once hopeful and ominous: A tiny bull kelp stem with a single blade sways in the currents, reclaiming a spot on a once barren reef. But, looming large in the background, the shadowy figure of an urchin readies to seal the new start’s fate. For marine ecologist Tristin McHugh, who took the picture while diving a Noyo Harbor site that had recently been scoured of as many urchins as possible, the moment was emotional. “Although we didn’t see any giant bull kelp showing up, we did see a ton of tiny bull kelp starting to emerge very soon after we started,” she said during a recent Noyo Center for Marine Science presentation on the pilot project she managed for the nonprofit Reef Check. “It was amazing seeing tiny, tiny bull kelp emerge.” The rapid decline of the North Coast’s once thriving underwater forests has been well-documented in recent years, with the coasts of Mendocino and Sonoma counties bearing the brunt of what scientists describe as a “perfect storm” of changing oceanic conditions
that ultimately decimated red abalone populations. While ebbs and flows in the undersea ecosystem occur naturally, McHugh says the devastation wrought in those areas has been intense, with more than 95 percent of the waxy bull kelp canopies gone in less than a decade. “It happened very quickly,” she says. The stage for the bull kelp’s disappearance was being set back in 2013 when a still mysterious wasting disease began decimating starfish populations up and down the Western coast. Especially hard hit was the sunflower star — a voracious, 24-armed predator that can swallow a sea urchin whole — which has yet to rebound. “The Warm Water Blob” — essentially a marine heat wave — entered the scene next, stressing bull kelp forests that are dependent on nutrient-rich cold waters to thrive, only to be followed by another round of high ocean temperatures with the “Godzilla” El Niño in 2015. In the wake of these climate change-driven anomalies, a “negative feedback loop happened,” McHugh says. Bull kelp forests were left in a weakened state and fewer new stocks settled onto the region’s rocky reefs, removing vital food sources from the ecosystem. That, she says, drove sea urchins —
“Although we didn’t see any giant bull kelp showing up, we did see a ton of tiny bull kelp starting to emerge.”
A tiny baby kelp emerges at the Noyo Harbor pilot site. Credit: Tristin McHugh/Reef Check
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NORTH COAST JOURNAL • Thursday, April 15, 2021 • northcoastjournal.com
