Urchin Explosion

THE UNDERWATER BATTLE BEING WAGED ALONG OUR COAST

My first attempt to free dive for red abalone was with a group of Santa Cruz–based surfers who took to the water like sea otters—popping underwater to come seemingly right back up holding a magnificent sea snail, then popping back down for another. After a while of watching from the Point Arena Pier in Mendocino, I finally worked up the courage to join them. Making my way through the churning Pacific, it felt like being caught in a washing machine. And then there were the frequent stops needed to disentangle myself from long strands of kelp.

As soon as I reached the guys, one passed me his weight belt—he had already bagged the daily limit of three. Another coached me, “Dive down about 12 feet, and there’s a big one under the rock.” I checked to make sure my mesh collecting bag and small metal bar for prying the abalone off the rock were ready, but inwardly I was thinking, “You’ve got to be kidding.”

I made it down to the designated rock, a feat in and of itself, but didn’t see the abalone through the murk, let alone take it by surprise and insert the bar between it and its rocky home. I made a few more attempts, each time drifting farther away from the rock, acutely wary of being entangled and trapped by kelp—and drowning.

I would not have been the first abalone casualty. Already that season, only seven months long, nine people had died in Northern California while diving for abalone. The specific causes of death varied—some did fall victim to kelp ensnarement and drowned, others were caught in rip tides and dragged out to sea, some were trapped in underwater caves by pounding waves. Over the years, people have fallen off cliff s while scouting a new abalone spot, and others have had strokes and heart attacks far from cell service, much less medical care. And, on occasion there have been Great White bites. Despite these dangers, thousands have continued to seek out this iconic delicacy each abalone season.

Empty handed, I began to make my way back to shore, choosing a calmer route close to the pier. There, I discovered an underwater field of purple sea urchins. It was a little eerie, as nothing else appeared to be living there, but these were low-hanging fruit compared to the abalone. I plucked the biggest ones and put them into my bag. Truth be told, I prefer eating the urchins’ creamy roe, or uni, to abalone anyway.

Back at our rental house, while the guys cleaned and tenderized the abalone for our dinner, I opened the urchins and removed their custardy gold roe sacs. Smaller than the red urchins that are harvested commercially and commonly offered in Japanese restaurants, the purple urchins still offered exquisite roe. The brightest-colored, firmest roe we ate right out of the shell. It was both sweet and briny, and tasted of flowing kelp and deep upwells and everything magical about our coast.

The less pristine roe we blended into a buerre blanc sauce, destined to be paired with a bit of bacon and arugula in an uni carbonara. What uni we had left was mixed with unsalted butter (a ratio of 40% uni to 60% butter) and frozen in small containers. These little flavor packets are fantastic to have on hand for tossing on soba noodles for a quick and delicious meal.

The uni feast went a long way toward assuaging my disappointment at not getting an abalone that day, but I was already plotting my next attempt.

ABALONE VERSUS URCHIN

While abalone had been showing signs of decline for some years prior, mass mortalities of the sea snails started in 2017. With no improvement in sight, the California Fish and Game Commission, having determined that the population was too reduced and vulnerable to allow even limited recreational harvesting, canceled the 2018 season entirely, and announced that it would remain closed until at least 2021.

While the indefinite closure is a major disappointment to those who ritually dive for and eat abalone, and a significant economic blow to the coastal businesses that thrive on the outfitting, housing and feeding of these recreational divers, the real crisis is the one that is taking place underwater.

In the simplest of terms, the problem is that abalone eat kelp, and the kelp along our coast is largely gone. In fact, scientists estimate that bull kelp forests are down 90% since 2014.

Bull kelp is an annual alga species. Under normal conditions, they release their spores in late summer and fall—prior to the arrival of winter storm waves that rip out much of the mature kelp. The spores grow rapidly in the nutrient-rich, cold waters along the Northern California coast, forming kelp forests that shelter and feed a whole host of other marine life.

“Kelp forests provide habitat and food sources for many animals,” Cynthia Catton, PhD, an environmental scientist with the California Department of Fish and Wildlife (CDFW) currently conducting research on the crisis from the UC Davis–Bodega Bay Marine Lab, said during our interview. “As well, they filter out sunlight coming through their blades and are responsible for massive photosynthesis and respiration in the water. Not having them drastically impacts ocean ecosystems.”

She went on to explain that when the ocean is in balance and food is abundant, abalone and sea urchin, which both feed on the kelp, can co-exist happily. In fact, urchin can actually benefit abalone— urchin typically live in the crevices in and between underwater rocks, and baby abalone shelter beneath them, protected from predators by the urchin’s spines. And when urchins transfer food to their mouths, located on their undersides, the baby abalone are also fed.

When there’s not sufficient food, however, urchins adapt. “Urchins are able to adjust their behavior and increase the size of their jaw and teeth, and have access to more food,” Catton said. “They come out of crevices and form ‘feeding fronts.’ These are urchin barren conditions.” This explained what I had seen in Point Arena; and leaves baby abalone without their shelter, as well as an important source of food.

While adaptive, “urchin barren” behavior is not sufficient, even for the urchins themselves. Catton explained that while red and purple urchin numbers have not declined as precipitously as the abalone, they are starving. Red urchins are now largely empty of roe, their means of reproduction, so their numbers are dropping significantly. Purple urchins have much less roe, as well, but apparently enough to reproduce—hence their takeover.

According to Catton, the kelp decimation is due to a “perfect storm” of environmental stressors that have triggered shifts in the entire ecosystem. In 2011, there was a toxic algal bloom along the Sonoma coast that killed off many invertebrates that live in shallow waters, including huge numbers of abalone along with sea stars, and even urchins. This set the stage for the 2013 outbreak of “Sea Star Wasting Disease,” which impacted the West Coast from Baja to Alaska. Kelp forest dwellers that feed on sea urchin, the sea star die-off resulted in an explosive growth of urchins. Next, a marine heat wave or “warm blog” hit in 2014, then the strong El Niño of 2015 ushered in warmer waters, which have fewer nutrients than cold upwellings normal for Coastal California—and are required for kelp growth.