A margarita mixer filled with glass shards that costs as much as a new car is just one of the tools used to study infections in cod fish.
“I use it to liquefy spleens,” says graduate student Aaron Frenette. “Basically a soup made up of host and parasite.”
The hands-on research Frenette and his colleagues are doing at Bailey Hall at UNB is centered on identifying and limiting infections in codfish.
It’s all part of the process that could improve fish farming.
“By blending up specific fish organs that have been identified as target tissues for parasite infection, ,” explains 26 year-old Frenette we can determine the parasite infection intensity within an individual fish,“
It tells us which families of fish suffer the most from this infection, and which ones are less affected.”
The infection, known as Loma morhua xenomas, or Loma, is a natural sickness in cod. It’s a nasty bug that spears healthy fish cells with its harpoon-like structure that lays coiled inside itself, before shooting out, several times its own length, injecting its genetic material into the cod fish in the blink of an eye. Once infected, the fish cell bloats, becoming white cysts on the fish’s gills and spleen. Those eventually burst, birthing thousands of new spores.
“Given the decline in wild fish stocks, there is plenty of interest in introducing cod to large scale aquaculture,” says Frenette. “The industry has focused on the production of cod families with traits desirable for large scale culture”
“The cod fisheries collapsed in the 90s,” said Frenette. “So, our study on this infection is a step into rebuilding it.”
Salmon has been the traditional choice for fish farming; but, as the industry grows and diversifies, so does the need for the research to make those avenues successful. Atlantic cod can sometimes grow close to 100 kilograms in the wild – no small fry. A fish that size is comparable to a domestic sheep. While the farmed varieties are considerably smaller, sometime around 5 kilograms, from a farming perspective, it’s still a lot of fillets.
“Our studies are really the groundwork, as nobody else has looked into this,” said Frenette. “Understanding it will go a long way to making cod aquaculture feasible.”
Like regular farms, the animals are raised in fences. It’s easier to just build those fences right in the ocean. Pens, like those off the coast of northern Iceland, where Frenette has done research, are where thousands of fish are raised at a time.
Those operations are similar to ones done off the coast of Atlantic Canada. It’s done offshore because building tanks on land is much more expensive. But, because the fish are being raised in their natural habitat, it means they’re at risk of the same dangers as those in the wild.
When one fish is infected while sharing a pen with a thousand others, it doesn’t take long for it to spread. From there, Loma acts the same as the common cold in a crowded classroom; it affects everyone around it. Some more than others.
Why some fish get sicker than others is also part of Frenette’s research. It’s also where the incredibly expensive margarita machine comes in.
Developing these tests and continuing his research keeps Frenette in his lab more than his home.
“It’s not a job; it’s a life style,” he said. “I do love it.”
About a year from earning his biology doctorate, Frenette has travelled to different northern countries. He’s spent time in Ireland, partnering with Queens University of Belfast. Last summer saw him in Reykjavik, Iceland, mapping where the parasites are found in the wild. It’s also taken him to Maine and New Hampshire, and he works closely with the Huntsman Marine Science Centre in St. Andrews. He’s also worked out of Memorial University in Newfoundland, where they have the resources to hold small populations of the large fish.
“UNB doesn’t have the facilities to recirculate large amounts of sea water here, so we rely on partnerships to do some work,” Frenette said. “I’ve been very fortunate to go where I have with it.”Tweet