Selective breeding by researchers at Vancouver Island University (VIU) has resulted in what Timothy Green, Director of the Centre for Shellfish Research, termed “future-proof oysters.”
In 2018, the oyster industry in Canada was faced with a problem. Most of the oysters being grown in Canada were sourced from “seed” grown in the United States, which was becoming increasingly susceptible to acidic conditions in the ocean.
In response to these challenges presented by climate change, Green collaborated with the Department of Fisheries and Oceans (DFO) to collect a variety of oysters from 19 separate “families” located in British Columbia, Washington, Chile and the U.K. The goal, according to Green, was to develop a robust oyster that was fit for the B.C. aquaculture industry.
“Our industry was very reliant on importing seed from overseas countries. There were oysters coming from Guernsey, oysters coming in from U.S. hatcheries; a lot of the industry was reliant on shellfish coming in from Chile. So, that created some issues around sovereignty, and safe supply and what happens if one of the countries has a disease and introduces it to Canada,” said Green.
To determine which oysters would sire the next generation in their mission to make a climate change-resistant oyster, Green’s team at VIU used sib testing, which mathematically analyzes the traits of the male oyster’s siblings to choose which male oyster will be allowed to pass on their genetics.
“Let’s think about a dairy herd. You can easily go measure the amount of milk, and milk is what you really want from all your cows. But who do you choose to sire the next generation? You can’t measure the milk from a bull, but you can measure its sisters, its mother, its aunts and its grandmother and mathematically determine if that bull has the genes for making lots of milk,” said Green.
“We do exactly the same. You look at all the families, you rank them and you choose individuals where if you mix those two, you’re going to end up with an animal that’s moving forward in the trait that you’re interested in.”
Similarly to the way land-based agricultural practices have selectively bred cows and chickens to be larger and more uniform in how much meat they provide to their respective industries, Green said his team sought to provide consumers with a uniform oyster eating experience and companies with a steadier stream of desirable shellfish.
“If everyone is growing the same, there’s less grading that has to take place. There’s less labour input, damage to the shells and potential mortality from handling,” said Green. “We’re not trying to compete with the U.S. in the shucked product market, where you’re selling oyster meat. We’re looking at that high-end, half shell oyster.”
The result, according to Green, has been a resounding success. Before the oyster breeding program started in 2018, roughly 80 per cent of oysters were dying before they were harvested. That number has dropped to around 20 per cent, owing to the added resiliency of these selectively bred specimens. In response, Green said the oyster industry in British Columbia has largely switched over to the oysters developed at VIU.
“When I started, 80 per cent of the oysters were being imported. Now, 80 per cent of the oysters in the B.C. industry are produced in B.C.,” said Green.
The oyster breeding project is far from over, according to Green. He said that he and his team are taking steps to begin genetically testing oysters to determine specific genes that produce their list of desired traits. Green also said that the methods of his breeding program could be repeated with other species of oyster, such as the Eastern oyster in
Atlantic Canada.
“Every time you transfer into a new bivalve, it just gets easier and easier. You’re not making some of the same mistakes you made the first time around. So, I think the costs of genotyping will be able to dramatically go down for the Eastern oyster,” said Green. “The U.S. industry is also investing a lot of money into breeding and developing tools for the Eastern oyster, so I think everything will move quite quickly.”
