Eat the Invaders
When invasive species decimated maritime industries in Nova Scotia, the members of two UNESCO Biosphere Reserves had to find innovative ways to restore equilibrium.
TEXT Shannon Webb-Campbell PHOTOS Catherine Bernier
Since the glaciers retreated after the last ice age, Nova Scotia/Mi’kma’ki has been a coastal paradise, especially for the Mi’kmaw people, who have nurtured and sustainably harvested its abundant sea life throughout their long history. But warming waters in the Atlantic Ocean have brought new threats.
Two invasive species have struck different parts of the province: the MSX parasite found in oysters on the Bras d’Or Lakes, and the green crab in Southwest Nova.To defend themselves against such threats, communities in these two regions came together to seek designation as UNESCO Biosphere Reserves, which promote solutions reconciling the conservation of biodiversity with its sustainable use.
The Southwest Nova Biosphere Reserve was established first, in 2001, and spans five counties and multiple ecosystems along the Bay of Fundy and Atlantic Ocean. The Bras d’Or Lake Biosphere Reserve, established in 2011, encompasses a large tidal body of salt water in Cape Breton that reaches out to the Atlantic in three arms.
Through innovations that jointly benefit their regions’ social and ecological systems, these two biosphere reserves offer a template for how humans and nature can thrive together.
Where all Things Flow
Waking up at dawn in Cape Breton/Unama’ki (the “land of fog” in Mi’kmaw), I slip my winter coat on over top of my nightdress and sip coffee overlooking a salty stretch of inland sea on the Bras d’Or Lakes. As the sun rises, I watch a great blue heron and her young feed along the shoreline. I think of the Mi’kmaq and non-Indigenous fishermen who would’ve been up long before me to be out on the water. And I remember the nearly decimated oyster beds below.
The Mi’kmaw word for the Bras d’Or is Pitu’paq, or the place “to which all things flow.” The interconnected bays, islands, channels, and estuaries of the Bras d’Or Lakes region were carved out of sandstone during the last glacial age. This vast estuary spans nearly 1,100 kilometres, and its natural abundance has been protected and sustained by the Mi’kmaq for thousands of years.
In 2002 a parasite called MSX, or Multinucleated Sphere Unknown, was first detected in the Bras d’Or Lakes. Harmless to humans but deadly to oysters, the disease had already devastated oyster industries in Chesapeake Bay and Delaware, and it would soon do the same in Cape Breton.
“When MSX started to show up, it basically prevented the oyster from digesting their food, so they starved to death,” explains Eileen Crosby, Chair of the Bras d’Or Lake Biosphere Reserve Association. “They would start out okay as a small oyster, and then they would die.”
The arrival of MSX was particularly disastrous for local communities, who had been investing heavily in developing their oyster fisheries for decades.
Bras d’Or oysters were once shipped to high-end restaurants across Canada and internationally and were a ubiquitous local treat, especially during holidays. Today most oysters eaten in the region come from elsewhere. “MSX completely destroyed the oyster industry,” says Crosby.
For Thomas Johnson, executive director of the Eskasoni Fish and Wildlife Commission, the oyster has long been a central fixture of daily life. He came to the oyster farm as a little boy and still remembers how people lined up to make strings of scallop shells, which were hung off the wharf in order to collect oyster seeds for redistributing to other ideal areas nearby.
“It created a lot of jobs. My parents were involved. You got paid on a daily basis for so many strings. A lot of people were there. I remember the smell of the oyster and scallop shells as a boy,” says Johnson, who is a first-language Mi’kmaw speaker and has worked with Eskasoni Fish and Wildlife, which manages communal fishing licences and conducts research, for over two decades.
Beyond their economic impact, oysters thrive in the brackish water of the Bras d’Or Lakes and are critical to the local ecosystem. They secure the shoreline from erosion and provide habitat for other species that live under or on top of them.
Most importantly, oysters serve as a powerful filtration system for the entire estuary, significantly mitigating pollutants: a single oyster can filter five litres of water per hour.
Not just an extraordinary cleansing agent, oysters are also delicious superfoods. The tender pear-shaped pocket of meat—which can taste briny, salty, sweet, or even buttery—is chock full of essential vitamins, minerals, and antioxidants. Oysters offer a rich source of protein, zinc, vitamins C and D, iron, copper, niacin, and riboflavin.
The oyster has long been significant to the dietary health of the Mi’kmaq, who also use them for spiritual and ceremonial purposes. The Wampum belt was made out of beads crafted from oyster shells, which can also be used as smudge bowls for sage.
Although Bras d’Or Lakes is now considered MSX positive, there are areas of the lakes where the disease has not been detected. It’s unclear if these oyster beds have a natural resistance, or if they simply haven’t yet been exposed to the parasite. While oyster populations have been in decline due to overfishing, pollution, habitat changes, and MSX, the Eskasoni Fish and Wildlife Commission, Fisheries and Oceans Canada, and other stakeholders have been working together to breed oysters that are immune to the disease. “The oyster is still in recovery mode. The disease is here to stay, and it’s not going away,” says Thomas Johnson.
“We are speeding up Mother Nature’s way of producing a disease-resistant strain of oyster. If we can produce some disease-resistant offspring, we can assist in bringing back a healthy population.”
— Thomas Johnson
While the Bras d’Or oyster recovers, the Eskasoni Fish and Wildlife Commission and Mi’kmaw oyster farmers like Joe Googoo have been working tirelessly for the past five decades to restore oyster populations in other parts of the estuary. In nearby Whycocomagh Bay, Googoo has over half a million oysters stored in floating trays, submerged less than a metre deep in the water.
Googoo, a first-language Mi’kmaw speaker who teaches oyster farming methods to youth in hopes of sustaining the industry for seven generations, has been experimenting with this method since 2008. Despite suffering some losses to MSX, he’s had some recent successes. The oysters on the surface have survived due to the mix of fresh and salt water, as the MSX virus cannot survive in fresh water.
The Eskasoni Fish and Wildlife Commission and local Mi’kmaw oyster farmers like Googoo strive to employ Elder Albert Marshall’s philosophy of Two-Eyed Seeing, which means “trying to take traditional knowledge from the past and incorporate it with science, and meet somewhere in the middle for the benefit of the ecosystem,” says Johnson.
“Mi’kmaw knowledge and Western knowledge work really well together, especially with the oysters,” says oyster biologist Allison McIsaac.
For example, oysters naturally settle on eelgrass, but when the grass dies in the fall, the oysters are blown ashore and die too. The Mi’kmaq have traditionally collected oyster seeds from the eelgrass and moved them to locations where they grow best.
“We work with a lot of people who know the area,” explains McIsaac. “There is no need to go out and take temperatures and salinity to prove it’s a good area if they’ve been working it for decades.”
Despite the challenges of reviving oysters in the Bras d’Or, McIsaac is optimistic. She believes oysters are incredibly resilient animals. After all, they survived the last ice age; with a bit of help, they’ll survive MSX too.
Crabs in the meadow
Like-minded researchers and Indigenous innovators in the Bras d’Or Lake Biosphere Reserve have had recent successes growing oysters in suspension. When hung from buoys, oysters are protected from predators like the green crab, another invasive species wreaking havoc in the Maritimes.
The green crab has been in North America since the 1800s, but in the last half century, warming ocean waters have enabled it to travel up the Atlantic coast to the Southwest Nova Biosphere Reserve, a six-hour drive southwest of Bras d’Or.
Beneath the turquoise waters along the ocean’s edge at Kejimkujik National Park Seaside, the green crab has been busily ripping up seabeds and undermining the ecosystem since it arrived in the early 1990s.
The full impact of its presence wasn’t appreciated until 2009, when Parks Canada began noticing parts of the seaside were different or missing.
The most glaring ecological change was the disappearance of the eelgrass, which bloomed in bright green meadows underwater. When the tides were low, biologists noticed something else: thousands of clam shells littered the mud flats, looking as though they had been attacked by nail clippers.
To combat the problem, Parks Canada began catching green crab for six months of the year. Every day, they went out in rowboats and dropped 140 modified shrimp traps into the blue-green water; every day, when they hauled in the traps, they were overflowing with green crabs. In this way, they removed over one million green crabs between 2010 and 2014. “Our eelgrass returned in spades. Today, we are back up to 36 per cent of the historic extent for Keji Seaside,” says Gabrielle Beaulieu, manager for the coastal restoration and resilience project at Parks Canada, who has been working with students and collaborating with stakeholders to defend seagrass from the crab for the last five years. In 2017 Parks Canada created a hot spot strategy, which continues to maintain the population, catching 15 crabs per trap and using only 30 traps.
Despite these efforts, the green crabs persist. Parks Canada, far from discouraged, has been thinking outside of the box in terms of seizing the culinary opportunity. They have also been working with McGill University to transform crab shells into a biodegradable plastic and Dalhousie University to create a concentrated fertilizer.
In the places where green crab originated, along the coast of Spain and Portugal and in the Mediterranean, green crab are treated as a delicacy.
In Italy, for example, green crab trapped during their brief soft-shell moulting phase can sell for €40 a pound.
Drowned in egg batter and dipped in corn flour, the small crustaceans are served deep-fried in a dish known as moeche or moleche.
In Nova Scotia, green crab aren’t as prized—at least, not yet. Chef Paolo Colbertaldo, originally from Venice and now the owner of Lincoln Street Food in Lunenburg, Nova Scotia, has cooked with the green crab, which he describes as tasting “shellfishy.” He recently served it with sweet potatoes in a soup, and has also made a fish sauce from it.
“The mentality for using invasive species is different in Italy, they just use it,” says Colbertaldo. He says the challenge of introducing green crab as a delicacy to Nova Scotia lies in the difficulty of harvesting the moulting ones, because “the green crab is a mean little bugger.” Still, Colbertaldo intends to use the crustaceans whenever he can get his hands on them.
I am going to make a soup with them, and top them with a scallop or corn and wild mushroom dumpling. That kind of stuff.
— Paolo Colbertaldo
Acadian lobster fisherman Lucien LeBlanc is skeptical of a market emerging for green crab, given their small size. While they have some utility as springtime bait, he mainly wants to see them gone. “Considering the green crab is an invasive species that is quite harsh on its local environ‑ment, I personally feel the more they can be fished and removed from the ocean, the more our local species will thrive,” he says.
LeBlanc is holding out for a more high-tech solution, like the project being developed at McGill University in Montréal. Dr. Audrey Moores’ green chemistry lab is attempting to make plastic cutlery and cups from a chitin (a type of protein) found in the shell of green crabs.
This past winter, Moores and her team extracted chitin from the green crab, and are currently taking the next steps to turn it into a degradable plastic material.
“If we can remove this invasive species and in return make a plastic product that could be used in a variety of situations, that would be a win-win for most who make their living on the ocean,” says LeBlanc.
Whatever solution emerges as the best way to make the most of the green crab, the UNESCO Biosphere Reserve is, for better and for worse, the ideal place to find it.
“Every biosphere means there is something special about that place,” says David Sollows, chair of the Southwest Nova Biosphere Reserve. But what ties them together is the commitment to combining Indigenous knowledge and Western scientific approaches promoting biodiversity and creating sustainable opportunities that will endure for generations.
In both the Bras d’Or Lake and Southwest Nova Biosphere Reserves, Indigenous knowledge-keepers, chefs, parks employees, ecologists, fishers, and community members are coming together to protect their ecosystems for future generations. We can’t turn back the clock, but through collaborative approaches like these, we can find new harmonies with nature in our changing world.
To learn more about how traditional Mi’kmaq knowledge and western science are being used to bring oysters back to the Bras d’Or Lake, or more about how the people of the Southwest Nova Biosphere Reserve innovate new ways to deal with invasive green crabs, check out Episode 4 and Episode 9 of Striking Balance, a TVO original documentary.