The harvesters donned their wetsuits, grabbed their scissors, and launched their yellow kayaks into the ocean from the pebbled beach. We followed close behind, excited for our first observation of this kind of commercial harvest.
As we carefully navigated our way through the rocky shallows, I could see a dense assortment of small understory seaweeds. Paddling out farther into the morning mist, I scanned the water eagerly for our target—the largest seaweed on the north coast of California, and one of increasing conservation and management concern.
Of comparable majesty to the ancient redwood trees onshore, the towering bull kelp, Nereocystis luetkeana, is a large brown alga that can grow up to about 130 ft. from the seafloor to the water surface. It has one smooth, thick stipe, analogous to a tree trunk, and carries all its leaf-like fronds at the top, buoyed up by a round gas-filled float called a pneumatocyst (pronounced “new-mat-o-sist”). Groups of bull kelp form large underwater forests that serve as a habitat for hundreds of marine species including urchins, abalone, and fish.
Unfortunately, bull kelp forests off California’s northern Sonoma and Mendocino counties have undergone large declines. From 2014 to 2020, bull kelp canopy in these counties declined by about 95 percent (compared to the 1984-2013 historical average). The decline was largely caused by warm water, abundant native urchin grazing, and a disease that significantly reduced sea stars, which prey on urchins.
In response, the California Department of Fish and Wildlife (CDFW), California Sea Grant, and others are developing new strategies to protect and restore bull kelp. One position born of their partnership is the Kelp Management Extension Fellowship, primarily created to produce the Kelp Enhanced Status Report. In addition to California Sea Grant, CDFW is also collaborating with Native American Tribes, commercial and recreational fishermen, academics, and NGOs to develop a Kelp Restoration and Management Plan to support long-term and sustainable management of kelp. As part of this process, CDFW facilitated a Bull Kelp Working Group to discuss potential changes to commercial bull kelp harvest regulations, and is supporting kelp recovery research.
On this still, June morning, CDFW Kelp Specialist James Ray and I observed a CDFW-licensed kelp harvester during a routine operation in Del Norte County. California’s northernmost counties, Del Norte and neighboring Humboldt counties, have not experienced the large bull kelp declines seen in Sonoma and Mendocino counties, and most of the state’s bull kelp harvest occurs there.
As we drifted along, bull kelp materialized through the fog on the water’s surface, each with dozens of fronds streaming behind it like a mermaid’s wavy green locks. James and I watched as the harvesters selected the bull kelp they would harvest. Pulling up alongside one harvester, I watched as he firmly grabbed the top of a thick stipe and heaved it across his kayak. Bull kelp fronds are thick, slimy, and heavy, and can be up to 13 feet long, so this was no easy task! In June, the big bull kelp are robust adults that have survived the previous winter to reproduce again early in the season.
The harvester carefully tied a bit of thin red rope around the base of the slippery blades and cut them with scissors about 1 ft. above the pneumatocyst. Next, he slid the fronds into a large white bag on his lap, and then started paddling for his next target.
After about an hour of harvesting, the boats were full, so we returned to the beach. In total, fronds from about 60 individual bull kelp were harvested, and many more remained in the water.
Next came the hardest part: lugging the seventeen 50+-lb. bags of kelp up the beach to the delivery truck! Once the truck was loaded, it hurried off to get the kelp processed, and the harvester’s work was done. Finishing harvest around noon, it was not a full day of work, but back at the processing facility workers would spend many days sorting, drying, and packaging the fronds to be sold as human food.
It is extremely useful to observe and learn from kelp harvesters as well as Tribes, recreational harvesters, researchers, and others as we develop the statewide Kelp Restoration and Management Plan, and we look forward to working with kelp and seaweed users in the coming years.
post by Gina Contolini, California Sea Grant