By Ian Norton, Reef Check Northern California Survey Coordinator
After a summer spent observing and monitoring the kelp restoration site in Fort Bragg, California, I noticed something peculiar. A wind-swept 14ft@17sec swell washed over the site in late September, the largest since the project began. After the dust had settled, fellow restoration technician Morgan and I dove the site to assess how the site had weathered the storm. I spotted a boulder, approximately basketball size, that hadn’t been there before. Attached to the boulder was a large holdfast, anchoring a fully grown Nereocystis (bull kelp) sporophyte. The stipe extended all the way through the water column to the surface. I realized I was observing a fully mobile individual, capable of traveling great distances, borne aloft on the crests of ocean waves. I imagined that small to medium swells must result in small to medium steps for this wayfarer, but surely excessive wave height would result in leaps and bounds, potentially casting this specimen many miles from its natal reef. And it was not alone in kin or company, for I observed no less than a dozen similarly-attached drifters throughout the site, and spied numerous invertebrates and epiphytes of one form or another sheltering in its holdfast, encrusting and sprouting from stipe and blade.
I’ve known kelp can become vectors for transport by tearing loose and forming “wracks”, but I’d never observed kelp carrying its own personal anchor, bouncing from inlet to inlet, dispersing spores from its native forest, picking up and dropping off passengers while it idles between Pacific storms. Sure enough, after a second large swell passed through, some of these visitors were gone, and several more had appeared seemingly out of nowhere. Those that remained were either wedged in fissures and couldn’t be wrenched free, or had attached to a particularly large boulder, likely requiring a more energetic set to be wrested from where they lay. As weeks passed, in accordance with their yearly cycle, the kelp stipes broke free from their bounds, and the resulting holdfast was consumed presumably by urchin. All that remained was a strange rock on a foreign reef. I felt privileged to have caught just a fleeting glimpse of its journey.