Today’s oceans are awash with plastic. Tiny microplastics, often invisible to the naked eye, swirl in our tide pools. Large pieces of plastic debris stretch across vast stretches of ocean. Much of the ocean’s plastic pollution comes from land-based sources, but almost 20 percent comes from the fishing industry. Equipment falls overboard, fishing lines snap and spill waste into the sea, pots and buoys are abandoned, and fishing and aquaculture debris floats away.
Fishing nets and buoys lost on the seabed. Photo by Andriy Nekrasov via Shutterstock
Floats are a vital component of aquaculture and fisheries—there are hundreds of thousands of floats in use in the United States alone. The float market, already a multi-billion dollar industry, continues to expand 5.5 percent per year thanks to the growing interest in aquaculture. These floating spheres come in all shapes and sizes, and serve as anchors, markers, and navigational aids. For a long time, we have used wooden buoys, cork buoys, and iron buoys in aquaculture and ocean exploration. But today, the vast majority of ocean buoys are made from styrofoam or other polystyrene and polyethylene plastic compounds. There are thousands of buoys used for weather and navigational purposes alone, and every lobsterman and oysterman uses at least a few dozen.
The lost plastic buoys floated on the water and joined the tons of plastic that now cover up to 40 percent of the world’s seas. Pieces of plastic buoys break up or decompose in the ocean’s sunlight, along with billions of microplastics that end up in our seafood.
The Great Pacific Garbage Patch is made up of nearly half of what’s known as “ghost gear,” plastic fishing debris that’s been dumped into the ocean or left behind. Thousands of pounds of it wash ashore each year. Photo from Shutterstock
You can’t have aquaculture without buoys—but you can have buoys without plastic. Sue Van Hook had a lifetime of mushroom expertise when she joined Ecological design as a mycologist in 2007. Ecovative Design is a technology company focused on using mycelium—the fine white plant fibers of mushrooms—to solve human needs. After discovering during his research that mycelium could float, Van Hook quickly realized the potential for creating buoys.
Sue Van Hook, founder of Mycobbuoys, holding a red anchor buoy. Photo courtesy of Sue Van Hook
“My grandfather turned his lobster floats on a lathe back in the ’50s and ’60s on North Haven Island,” Van Hook said, recalling her first exposure to wooden floating devices in the aquaculture industry. “I watched him do all that, years ago, and we helped paint and all that. And then I watched the whole ocean go to Styrofoam, which at the time seemed like it was cool, right? It was cheaper. They didn’t have to go through all that work to make this beautiful thing individually, and it lasted a long time.”
As an adult, Van Hook became a professor of environmental studies and focused on mycology, a subject she taught at Skidmore College for 18 years. Now, observing the buoyancy of the mycelium, it didn’t take her long to remember her grandfather’s lobster floats and their conversion to Styrofoam—and to realize the environmental impact of an ocean full of Styrofoam. She set out to design and grow mushroom floats.
Newly painted buoy. Photo courtesy of Sue Van Hook
Currently the founder and CEO of his own company, Mycobuoys™, Van Hook pioneered the idea of replacing plastic buoys with mushrooms. To make buoys, Van Hook would take a sterilized hemp rope and inject it with a low percentage of wood-rot fungus mycelium. The fungus would then grow, spread, and take over any space it was given to fill. Initially, she used empty soda bottles, and today, she has buoy-sized prototypes that are over two feet in diameter.
Filling a bottle float. Photo courtesy of Sue Van Hook
Van Hook has had challenges finding the perfect mushroom for the job, and she continues to research the durability of floats. “We use wood-rot fungi,” she says, explaining that filamentous fungi that produce hardier, more aged mushrooms like reishi are better suited to the job than the lawn mushrooms that grow many culinary mushrooms. She has tested dozens of strains, and she continues to research mushroom varieties in float tests.
Float options. Photo courtesy of Sue Van Hook
Currently, Van Hook’s Mycobuoys™ is being tested at 11 oyster farms, shellfish hatcheries, and ocean schools across New England and New York. Her goal is to be able to guarantee the float for an entire season before selling it at retail.
Abigail Barrows was one of the first oyster farmers to test Van Hook’s Mycobuoys™. Barrows has a background in marine biology and researches ocean microplastics. In 2015, she purchased a lease Deer Isle Oyster Company with the goal of turning this place into a plastic-free oyster farm.
“We were fascinated by the process,” Barrows says of her early experiences with mycelium floats. “It was really exciting to grow something and then have this product, a functional product. And we were pretty excited about the potential applications when we started testing at sea.”
Abigail Barrows sorts Mycobuoys on her oyster boat. Photo by Kirsten Lie-Nielsen
The biggest challenge for Mycobuoys™ and those testing the buoys is their durability. In addition to a hard plastic body, many buoys today have a thick, toxic paint coating. To create a durable shell for Mycobuoys™, both Van Hook and Barrows experimented with natural paints that would protect the buoys from the sun, curious birds, and the rigors of ocean aquaculture.
“We’re still looking for a more durable coating,” explains Barrows, who used a resin-linseed coating and linseed-based paint on the buoys. “That would make them more durable, because boats will be banging on them, so we need to protect them for more than one season.”
“We’re trying to find a beautiful, environmentally friendly coating that will extend the life of the buoy,” says Van Hook. Today’s plastic lobster buoys don’t last forever—at least not as useful aquaculture tools. Most lobstermen and oystermen will use their buoys for 20 or 25 years. Van Hook’s goal for the durability of the Mycobuoy™ is a little shorter.
Handling ropes and buoys. Photo courtesy of Sue Van Hook
“My ideal business plan is that we grow floats every year,” she says. “You buy the floats at a reasonable price, you let them float on your cage for a year, and then at the end, we buy them back from you and dry them, grind them into fertilizer ourselves, or you can compost them in your garden.” Van Hook uses old mycelium floats in her garden, where she never has to add fertilizer or synthetic materials thanks to the nutrients of the mushrooms.
“You won’t have to store [the buoys] in your driveway or yard,” Van Hook continued, referring to the large piles of buoys that appear on fishermen’s lawns in the off-season, “where all the UV light breaks down the polyethylene plastic they’re using more quickly.”
New law in South Korea will ban the use of Styrofoam buoys by 2025and Van Hook believes other countries will soon follow suit. Van Hook expects her floats to retail for about 10 to 20 percent more than current plastic float prices, and believes that increased restrictions on plastic will only make mycelium an attractive option for floats. Foam and plastic floats average between $20 and $50, depending on size, while the cost of Van Hook’s floats will depend on the ability to scale production and a solution to the problem of durable coatings. Anyone interested in helping Van Hook trial Mycobuoys™ can contact her at website for buoy 2025.
Mycobuoys and a plastic alternative to oyster nets. Photo by Kirsten Lie-Nielsen
As oyster farmers like Barrows continue to experiment with buoys and Van Hook expands to more shapes and sizes, the future of Mycobuoys™ looks bright. In their quest to reduce ocean plastic, Van Hook may have stumbled upon the answer to more than just buoys.
“There’s so much potential here,” Barrows said. Plastic can be found in almost any fishing gear, from nets to boat buoy systems. The Great Pacific Garbage Patch is nearly half of what is known as “ghost stuff”, plastic fish are lost at sea or abandoned. In addition to Mycobuoys™, Barrows is also working on wooden oyster cage prototypes, and she sells her oysters in biodegradable oak bag from a new company called Providing ocean farms“We need to think outside the box, about using them as mooring buoys, other types of buoys, other marine systems like replacing foam boat hulls and marine docks.”
