The Clean Valley Community Interest Company (CIC) is attempting to usher in a greener future in the aquaculture industry.
Clean Valley CIC is based out of Dartmouth, Nova Scotia. The company was founded in 2018 with the goal of mitigating ocean pollution in the aquaculture industry while enhancing the quality and value of oyster farming. To do this, Clean Valley has mimicked the natural cleaning processes in the ocean by creating an Algae Biofilter, which uses algae and oysters to treat the water from land-based fish farms.
“We wanted to create a way to ensure that if we’re going to grow fish on land to feed the growing population, it’s not at the expense of the ocean,” said Nicholas LaValle, CEO of Clean Valley.
“Rather than sending any sort of discharge or wastewater from those facilities into the ocean, we can clean it and reuse it in the exact same way the ocean does.”
Clean Valley’s filter works in tandem with a traditional recirculating aquaculture system (RAS), which allows for aquaculture facilities to reuse water and reduce the amount of waste that is emitted into the surrounding environment. RAS systems, however, still emit some waste according to Clean Valley.
The waste that comes from fish in aquaculture farms contains high levels of nitrogen and phosphate, which LaValle said is exactly what algae needs to grow.
Clean Valley uses this nitrogen and phosphorous-eating algae as the first stage of their biofilter. The algae-rich water is moved down a series of four raceway tanks and into a sump pump, where it is then transported by pipes into the second stage of Clean Valleys filtration process — oysters.
“Oysters eat algae. That’s how they get that salty taste and are filled with all those omega-3s that are really good for our brains and our guts,” said LaValle.
Oysters are unique in that they can filter an average of 1.5 litres of water per hour through their gills. These gills are lined with small, filter-like structures called cilia that separate solid and semi-solid particles from the water. The oysters in Clean Valley’s biofilters sit inside at the end of the filtration process, after which the water is recirculated into the aquaculture facility.
On top of serving as a form of filtration for aquaculture waste, LaValle said that their oysters are able to be eaten after they’ve been utilized in the filtration process.
“We’re seeing some of our trials in Portugal proving that these oysters are not only growing bigger, but they’re also fit for human consumption by E.U. (European Union) standards,” said LaValle. “They grow not only in terms of size, but they grow in value. When you sell an oyster, you’re not selling it by the oyster, you’re selling it by its weight.”
LaValle claimed aquaculture has garnered a bad reputation in terms of cleanliness, farm management and its contrast with wild-caught fish, which is perceived as a cleaner, more natural product by consumers. He said that Clean Valley’s technology is aimed at not only aiding the environment, but improving the reputation of farmed fish.
“We’re trying to create trust in terms of fish that is grown and the products that are grown by this very hardworking industry. A lot of folks hear about farmed fish and they kind of get turned away. They don’t quite trust it because it wasn’t from the ocean or the lake,” said LaValle.
“Over 50 per cent of all fish come from a farm. That’s the fish that you’re getting on your dinner plate or in a grocery store, but yet people hear about farmed fish, they take a step back… What we’re trying to do is give people evidence-based data to trust in this fish; to feel that it’s not only natural, but it’s good for you.”
