Hakai Magazine

Bloodworms are the bait of choice for fishers in North America and elsewhere. Photo by BW Folsom/Shutterstock

Hitchhiking with Bloodworms

Invasive species are sneaking around the world, nestled in the seaweed used to ship bait worms. An easy solution exists, but the industry is resisting change.

Authored by

by Peter Andrey Smith

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Inside Phil Harrington Bait, a squat warehouse in Woolwich, Maine, a dozen men and women, several with hip waders rolled down to their knees, stand at counters, combing through piles of squirming bloodworms. The worms resemble puffy, blood-red earthworms laced with a fringe of feathery legs down each side. The worm harvesters, known locally as diggers, spent the morning on coastal mudflats at low tide flipping over mud with small metal rakes called worm hoes. Now they count worms into plastic trays, scrawling the total in pencil on scraps of paper.

Margaret Harrington, CEO of Phil Harrington Bait, wearing jeans and open-toed sandals oversees the floor. She holds a clipboard with one hand and sorts bloodworms with the other, stopping occasionally to sign a digger’s check. Her manner is matter-of-fact, and she has a laser eye for inflated counts or undersized worms. Diggers are paid by the piece—40 cents a worm on average, with bigger ones, the “selects,” fetching 60 cents. For many of the state’s 750 or so diggers, the work is a part-time gig, a way to make ends meet. In 2020, recreational fishing surged, and like in many years in recent history, Harrington says demand consistently outstripped supply.

But even without the added boost to the industry, bloodworms are big business. Harrington’s family enterprise, the largest bait worm dealer in New England, has been in operation since 1990, delivering the bait of choice to saltwater fishers angling for flounder, sea bass, and striped bass. Bloodworms are harvested primarily in Maine and the Canadian Maritimes. Remarkably, the trade, valued at more than US $6-million in 2019, is among Maine’s most valuable commercial fisheries. By weight, it’s second only to elvers (baby eels). Globally, these types of worms retail for as much as $606 per kilogram and, as noted in a 2018 review paper, “represent some of the most expensive marine species sold.”

But this isn’t a story about worms. It’s about the costs of what traditionally gets packed alongside the high-priced worms, and why it’s so hard to buck tradition despite viable alternatives.

hand holding bloodworms over a bucket

Bloodworm “diggers” along the Atlantic coast, from Maine to the Canadian Maritimes, harvest the worms from coastal mudflats and sell them to bait dealers. Photo by Robert F. Bukaty/AP Photo

Back at Harrington’s, a bearded man in a hoodie readies the worms for shipping, much as they have been prepped for almost a century. He methodically dumps 250 or so worms onto a screen, shakes off the excess ocean water, nestles the glistening worms on a bed of seaweed, and then covers the lot with newspaper. The seaweed, called wormweed—a subtype of the relatively common brown alga Ascophyllum nodosum, also known as rockweed or knotted wrack—acts like lightweight packing peanuts. Depending on their destination, the worms will be unpacked less than 24 hours later and sold as live bait in fishing shops throughout the United States. But it’s what happens to the wormweed that has marine biologists concerned—a tradition for the old-school industry appears to be creating liability for coastal communities on the receiving end.

Once a week for three consecutive weeks in the summer of 2011, FedEx delivered boxes of bloodworms to the Smithsonian Environmental Research Center in Edgewater, Maryland. Amy Fowler, a marine biologist who was then a postdoctoral researcher at the center and is now an assistant professor at George Mason University in Virginia, arranged the orders. Her goal was to see what role the bloodworm bait trade had in introducing invasive species from Maine to the mid-Atlantic region and elsewhere. When the deliveries arrived, she and her team prepped the samples for study, but it was largely up to Fowler to extricate the worms. “Everybody was a little … not super excited about handling the worms,” she says.

In addition to boxes from five different dealers, Fowler sampled five field sites along the coast of Maine, collecting wormweed from the shore. She inspected bait boxes at distributors in five mid-Atlantic states, and had an intern purchase smaller bags of worms and wormweed from bait shops, just as an angler would. The variety provided a way to compare samples from four points on the supply chain.

Fowler’s team then inventoried everything, removing all the hitchhikers, the species that clung to the worms and the wormweed. Then, they looked at species abundance and diversity in all of the samples, a meticulous and time-consuming process that revealed a microscopic world of substantial proportions: wormweed housed insects, mites, snails, and isopods. Fowler’s 2016 paper that resulted from the study—“Opening Pandora’s bait box”—reported an astounding 17,798 live organisms, collected from the field sites, 30 wholesale boxes, and 150 retail bags. A bag of worms and seaweed may not seem like much, but the cumulative effect is mind-boggling. Since 1946, Fowler estimates that bait dealers have unintentionally shipped some 1.2 billion organisms.

A variety of species, from periwinkles to amphipods, “hitchhike” on wormweed, the seaweed commonly used to pack bait worms. Photos courtesy of Amy Fowler

The study was significant, not only because it showed that the conditions keeping worms alive also kept a lot of other things alive, but also because it clearly showed the vector—the mechanism that moves organisms from one place to another. For most invasive species, vectors can be exceedingly difficult to pinpoint. For instance, container ships moving from busy port to busy port discharge billions of tonnes of ballast water, dispersing countless organisms multiple times at multiple locations over prolonged periods. The bait trade is comparatively small, and the vector more precise—a relatively straight line from source (bloodworm harvesters and dealers) to recipients (bait shops and anglers), and potentially into the ocean if wormweed is disposed of in the sea.

The simple act of surviving, however, doesn’t necessarily mean an organism will result in a problem. As Fowler saw it, the fate of many hitchhikers in the Chesapeake Bay ecosystem, near the Smithsonian Environmental Research Center, remained unknown. But three problem species almost certainly were introduced on both coasts by the bait trade: wormweed itself, which has the potential to spread and has taken hold in parts of the Chesapeake Bay and also in San Francisco Bay; snails commonly known as periwinkles that have physically altered habitat, reduced biodiversity in the intertidal zones, and displaced other animals; and the notorious green crab, an invasive species originally from the Baltic and northeast Atlantic that has damaged fisheries, decimated juvenile shellfish populations, and destroyed eelgrass beds, marsh grasses, and other habitats globally. Multiple federal, state, and local officials now monitor these aquatic invasives and attempt to control their populations.

“For such a kind of homegrown and niche vector, something that’s so small,” Fowler says, “[wormweed] still has a really large impact in terms of moving organisms around.” The cumulative economic losses from invasive species can be significant, particularly in terms of reducing valuable shellfish harvests. In a 2018 study, Fowler and her colleagues suggested that inadvertently shipping green crabs, for instance, could result in monetary losses to the shellfish industry totaling as much as $752-million.

Back at Harrington’s, I watch an employee pack a traditional bait box—bloodworms packed on seaweed—for US customers. That day, he and the other employees had also prepared trays of bloodworms, stacked 10 high and placed in polystyrene boxes, all bound for Europe. Inside each tray, the only living organisms: moist bloodworms. Shipping without seaweed reduces shipping costs, and worms overnighted to Europe apparently disembark none the worse for wear.

Despite difficulty in definitively calculating the total ecological toll of shipping wormweed out of Maine, the practice troubled researchers, who saw an easy fix: just stop packing worms in wormweed.

In an effort to come up with solutions to prevent the spread of invasives—including the simple suggestion that dealers could knock off about 85 percent of the hitchhikers by rinsing wormweed in fresh water, an idea Fowler and her colleagues tested—Fowler realized that wormweed has little or no effect on the survivorship of the worms. The seaweed seemed superfluous.

Emboldened by her work and evidence from several dealers, Fowler felt optimistic. She would talk with dealers; it wasn’t like she was trying to convince the global shipping industry to fundamentally change how ships discharge ballast water. And no one had to reinvent the wheel. The bait industry had already shown that worms could be shipped “naked in trays” as Fowler wrote in a 2018 paper. But, she says, “We just need to have them do that for all of the worms that are shipped throughout the US, right?”

Bait worms survive equally well whether they’re packed and shipped in wormweed or in dampened paper. Photos courtesy of Amy Fowler

Despite this logic, she made little headway. During one trip, Fowler remembers one worm dealer holding up a jar filled with salt water and pointing out the organisms dislodged from the algae swirling around as if the wormweed created a magical worm elixir. “At that point, I was like, ‘Okay, like, I can’t. I can’t convince them.’”

Where common sense and evidence seemed to make little difference, regulations have led to some innovation. Donnie Bayrd, a dealer in Milbridge, Maine, bought a paper shredder and now ships worms to California on shredded cardboard soaked in seawater. Other dealers use wet newspaper with success. Bayrd acknowledges that the wormweed contained other unwanted organisms such as green crabs, and said he changed his packing method in response to recent regulations in California, which were designed to curtail invasive species found in live bait, including seaweed. “They’re a little behind on the times because worms have been shipped out there on wormweed for over 60 years,” he says. “Nonetheless they were insistent that they not get any more of it.” For other domestic orders, he still uses wormweed. Bayrd says it’s just how they do things—his customers expect it, and besides, he doesn’t want to put seaweed harvesters out of work. Among his wormweed suppliers is Wade Reynolds, who says he makes $7 a bag and can make $800 on a good low tide. Reynolds is also a worm digger but says that picking wormweed is easier on his back. And while harvesting seaweed isn’t practical year-round, Reynolds says it’s useful supplemental income.

Dan Harrington, Margaret’s brother and an independent harvester who sells worms and seaweed to the family business, echoes Bayrd’s rationale. He harvests wormweed for the company and sees the two sides of the trade as traditional and in no need of change. “There are a lot of things that go on in the worm industry that work for us and have worked for a long time,” he says. (The industry contends that its perseverance owes a great debt to self-regulation, pointing to prohibitions on mechanical harvesting and digging on Sundays, as well as other informal conservation measures.)

Dan Harrington digs for bloodworms on the mudflats in Freeport, Maine

Dan Harrington digs for bloodworms on the mudflats in Freeport, Maine. Photo by Robert F. Bukaty/AP Photo

Shipping worms naked in trays might work for European customers, but in Dan’s eyes, worm dealers prop up a small yet important secondary industry of independent seaweed harvesters. He contends that rinsing seaweed is too onerous and undermines the algae’s cost-effectiveness, and he isn’t in favor of removing wormweed. “We’ve been shipping in seaweed for over 100 years,” Dan says. “If you start changing up what has worked for all these years, you’re potentially putting a whole ’nother portion of this industry at risk.” Dan instead favors an alternative solution on the receiving end, one that Fowler also champions: educate anglers that fishing responsibly means tossing unused bait and wormweed into the garbage.

For her part, Fowler believes eliminating wormweed is the right thing to do. She suspects there could even be cost savings for dealers and, while these changes would undeniably affect seaweed harvesters, it might be a small price to pay for vector management. Her scientific data has not yet proven particularly persuasive to the industry, even though some dealers can see another way. In her view, though, the missing piece would be convincing suppliers that repeat customers will keep buying bait, even when it’s bloodworms and bloodworms alone in their bait bag.

Later that morning, as I watch a refrigerated truck at Harrington’s get packed with bait boxes, it seems to me that the seaweed’s name—simply, worm plus weed—speaks volumes about the industry’s mindset. The bait worm business is steeped in tradition; the two just go together, like worms in wormweed.