Most docks in San Francisco Bay are home to a vibrant chaos of life commonly called the “fouling” community. This is because the things in this community grow abundantly and clog, or foul, things we would prefer clean, like pilings, ship bottoms, and nuclear-power plant water-intake pipes. To go find a public dock, to lie down on what is usually a splintered and bird- poop-covered platform and dig into what is usually murky green water to look for these creatures feels like an unseemly relative of tidepooling. It does not necessarily smell of the sea at its freshest, but you do find a lot of weird stuff.
Once, on a trip to examine dock fouling at Jack London Square in Oakland about a decade ago, I hauled up a thimble-size brown shrubby thing, like a little sandy snowflake. Its branches forked outward and had spots. It matched, in appearance though not fully in color, an abundant creature I had read about in my field guide called Bugula neritina, whose common name is “brown bryozoan.”
Now, it turns out it wasn’t. It took me a while to realize this. In the intervening time I learned some incredible stories about Bugula neritina. One thing I learned: mistaken identity may be where most people start.
In the late 1960s a lab at the National Cancer Institute found that something in Bugula neritina had the potential to suppress tumors. Over the next few decades scientists at NCI isolated the key compound, which they called bryostatin 1, and advanced it from lab studies to preclinical trials in animals to human clinical trials targeting several different types of cancer.
But the course of Bugula does not run smooth. The human clinical trial results were disappointing; bryostatin 1 didn’t beat cancer. Scientists also realized it wasn’t Bugula neritina that makes bryostatin. The actual compound appears to be the handiwork of a bacterial symbiont that lives with the Bugula. And it turns out it’s not just me who struggles to identify Bugula neritina; there are precious few bryozoan experts and even they might need close examination to tell Bugula neritina from other bryozoans.
Once scientists had identified the value of bryostatin 1 they naturally went out and gathered lots of what looked like Bugula neritina. But 14 tons of dripping sea creatures had yielded only 18 grams of bryostatin 1—“three full-grown African elephants reduced to the contents of a small salt shaker,” Stanford chemist Paul Wender told me. The cost and complexity of harvesting bryostatin 1 from nature didn’t match the reported benefit. As the supply slowly dwindled, it appeared that bryostatin 1 would be a medicinal wrong turn.
Have I mentioned that when it comes to Bugula, appearances can be deceiving?
Bryozoa is an oxymoron from the old Greek: bryo (moss) and zoa (animal). What we see when we look at bryozoans is actually a colony of dozens to millions of small animals, with animal features like mouths and guts and complex interpersonal dynamics. The colonies can take different forms, from elegant fans and trees to rubbery crusts and gelatinous goop clumps.
(A tangential mistake, entirely my own: the word Bugula clearly looks like it should be pronounced BUG-you-lah and appear in horror-movie font on Hollywood movie posters. Yet the scientists very clearly pronounced it BYOO-gyoo-lah. They were consistent on this point, but as I am writing this I am saying BUG-you-lah in my head. It is just fine with me if you read it that way too.)
Bugula neritina probably started out in the Indo-Pacific, but it has now traveled around the world and can be found just about anywhere. In San Francisco Bay, where surveys suggest that the vast majority of marine species are nonnative, Bugula neritina is one of the “dominant players” in the dock fouling scene, says Smithsonian Environmental Research Center (SERC) ecologist Andy Chang. The SERC group studies Bay invasions by dropping plates into the water in dozens of places and recording what grows on them over time. Though it’s unclear what specific harm Bugula neritina might be doing in an already-altered Bay, it is clear from the research that it’s fast-growing, fast-spreading, and flexible.
It turns out that so are lots of other bryozoans. The SERC group has found 25 species of nonnative bryozoans making a home in San Francisco Bay. Many of them, to my non-expert eye, look the same. “It’s a little bit like a mystery that you have to solve,” says Linda McCann, a research technician and bryozoan specialist at SERC. “You get better and better at solving them as you look at more and more of them.”
Almost all of us have non-expert eyes when it comes to bryozoans. Only a handful of scientists study bryozoans, says Megan McCuller, an invertebrate collections manager at the North Carolina Museum of Natural Sciences. And if you want something identified, she adds, “it’s just word of mouth. Contacting people. By people I guess I mean me and Linda.” (McCuller did mention one more bryozoan superstar, Judith Winston, who continues to study bryozoan taxonomy in retirement but has less of a public role.)
About six months after I had first found what I thought was Bugula neritina on the fouled dock in Oakland, McCuller found my uploaded photo and suggested it might not be Bugula at all, but instead in the genus Tricellaria, a different nonnative bryozoan. Color is one tell: Bugula neritina colonies actually tend to be purplish to reddish, while Tricellria tends to be tan. (Again, Bugula neritina, common name “brown bryozoan.” Go figure.)
Under a hand lens or microscope, Bugula neritina also lacks characteristics found in other bryozoans, including spines and a specialized type of individual bryozoa called an avicularia, which looks like a bird’s head and snaps at intruders with its “beaks.” Look even closer, though, and the situation gets more challenging, not less. What we label Bugula neritina is actually at least three genetically distinct look-alikes. Such species complexes are common among bryozoans, McCann says, and part of what makes them so intriguing.
“I think a lot of people don’t really care about bryozoans,” she told me. “Don’t think they’re that important. But they are so abundant in our seas. They’re in every part of our oceans. They’re in fresh water. They’re everywhere.”
The researchers at the National Cancer Institute eventually found a way to explain bryostatin’s ability to suppress tumors: it targets an enzyme called protein kinase C, or PKC, which plays a key role in promoting tumor growth. Because this is still a Bugula neritina story, though, there turns out to be a different path.
By the late 1990s, a lab led by Daniel Alkon at the National Institutes of Health discovered that PKC played a critical role in memory formation and storage. One form of PKC in particular, Alkon told me, is a kind of “master of ceremonies” for synapse growth and neuron protection. Alkon’s group searched the research literature for any compound known to activate PKC and be safe for human use. They found bryostatin.
Animal trials soon showed that bryostatin 1 could “enhance memory,” Alkon says. As scientists switched from cancer application to memory issues, a new problem arose: Only a few grams of bryostatin 1 remained at the NCI. Grabbing more from the wild was impractical. Attempts at Bugula neritina aquaculture had failed. The only hope for future study was somehow getting more bryostatin 1 without taking more Bugula neritina.
Many experts were pessimistic there would ever be a practical solution, but two groups, including Paul Wender’s lab at Stanford, managed at the eleventh hour to efficiently synthesize bryostatin 1 in the lab. In 2017, Wender and colleagues published a 29-step process to make clinical-grade synthetic bryostatin 1. “In science,” Wender says, “the impossible is possible.”
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Now Wender’s lab fields calls from medical researchers around the world asking for bryostatin 1. Among them are Alkon’s company, Synaptogenix, which has used Stanford bryostatin 1 in promising clinical trials on Alzheimer’s patients. In one recent trial, moderately severe Alzheimer’s patients who were given bryostatin 1 showed no significant cognitive decline over 42 weeks. “We were able to get a complete arrest of that progression with bryostatin,” Alkon told me. Other researchers have also suggested that bryostatin could benefit patients suffering from strokes, epilepsy, HIV, or multiple sclerosis. From a handful of Bugula neritina mailed to the National Cancer Institute in the 1960s, science has uncovered a rich world of possibility.
“We know nature has all sorts of solutions to problems,” Wender says. “But up until we developed the [right] analytics tools we weren’t able to understand. It was a library that was locked. Now we can go in, read what nature is doing, and build on it.”
You’ve heard the argument for conserving biodiversity because of the medicines as-yet undiscovered in the rainforest or among the coral reefs. It’s something of a delight to realize that it doesn’t just have to be exotic places. In the shadow of rusting cargo ships in the midst of our heavily urbanized estuary lives this wildly challenging species complex, a globally invasive nuisance dock fouler with a horror-movie name, whose symbiotic bacteria pumps out human medicine.
When I first started reading about Bugula neritina, I noted the journal articles about bryostatin 1 that mentioned its frustrating scarcity, while ecologists wrote about the ever-proliferating Bugula neritina populations in dock fouling communities worldwide. When I was talking to Linda McCann, the Smithsonian bryozoan expert, I mentioned that contrast and she paused. “I can’t imagine running out of this species, honestly,” she said.
Yet after finding out that my Bugula investigation had launched with a mistaken identification, that much of what’s labeled “brown bryozoan” in iNaturalist probably isn’t and that the bryozoan isn’t even brown, that the medicine maker turned out to be a symbiotic bacteria and not the Bugula neritina itself, that the tumor suppressor had turned out to be also a memory enhancer, I decided I needed to find at least one anchor of clarity. I had to find a genuine Bugula neritina.
At the peak of summer, on a wide-open Tuesday, I loaded some sample containers and my 10-year-old daughter into the car to go take one more look. Margaret regularly lists dock fouling as among her favorite activities. Once, when her sister and I were heading out in the morning to go running, she rolled her eyes and said, “well, the two of you wake up early to run. You and me wake up early for tidepools and dock fouling.”
We started at Jack London Square, where we had the public dock below Scott’s to ourselves. The restaurant hadn’t opened yet, but we could see the tables all set, wineglasses and big folded napkins out and ready for work lunches and celebration dinners. Once, as we were wrapping up a dock fouling trip in this spot, a school of bat rays glided by just at sunset, graceful fins rippling the surface. I remember the sun gleaming on the restaurant windows, the fog draped over San Francisco, the sailboats rocking and clanking in the breeze, our tubs full of bizarre orange and yellow and green life-forms, and I remember thinking this might be the most perfect place I know.
Now a few clouds floated overhead as Margaret and I chased some pigeons away and got to work. We caught a Bay pipefish fleeing to deeper water, and we found a trio of Hedgpeth’s sapsuckers laying eggs around the sea lettuce. Margaret yanked up a bryozoan from a large field of them, structurally appropriate but sandy in color, probably the Tricellaria I’d seen so many years ago.
For an hour or so we poked and prodded and brought things to the surface to examine. Finally, just as we had packed up to leave, Margaret reached way down under one of the dock platforms and pulled up a branching, distinctly purple bryozoan.
So was it Bugula neritina? The docks are home to so many creatures, and so many stories. One researcher I talked to forwarded me a list of other marine invertebrates linked to medicine: sponges, tunicates, snails, other bryozoans. You might find a backstory like Bugula’s for dozens of the animals living in a few feet of one crowded dock.
Inevitably we mix them up. Sometimes we get things wrong. But we always learn from the endeavor. In the end, attention rewards us with small moments of magic. About that, I feel, there’s no mistake.
