Scottish Startup Feeds Algae Whisky Waste to Save Wild Fish

Every year, fish farms rely on billions of wild-caught fish just to feed the fish they're raising. A Scottish startup is breaking that cycle by going straight to the original source of omega-3: algae fed on whisky industry waste.

MiAlgae founder Douglas Martin spotted a problem hiding in plain sight. Farmed salmon and other carnivorous fish need omega-3 fatty acids to grow, and nearly all of it comes from fish oil extracted from wild-caught fish. As aquaculture expands to meet global demand, it puts more pressure on already-strained ocean populations.

"The sustainable limits of what you can catch out of the ocean at the moment have been reached," Martin explains. "You can't physically catch any more out of the seas."

The solution required looking at omega-3 differently. Wild fish don't actually make omega-3 themselves. They get it from eating algae, which means MiAlgae could skip the fish entirely and grow the algae directly.

The challenge has always been cost. Growing algae on expensive feedstocks couldn't compete with cheap fish oil. That's where Scotland's famous whisky industry comes in.

Whisky production creates billions of liters of liquid waste every year. Distillers extract the eight percent alcohol from their fermented grain, leaving 92 percent behind as low-value byproduct. MiAlgae feeds that nutrient-rich liquid to algae cells in large stainless steel tanks, then harvests the omega-3 packed biomass.

"It's a bit like brewing," Martin says. "You take a very small number of algae cells and you take all the whisky byproducts and some other bits and you put them into these big stainless steel tanks and you let the algae feed on all of that nutritious goodness."

The company currently produces dried algae that pet food and aquafeed manufacturers can use as a direct replacement for fish meal and fish oil. Their first full commercial production site will produce thousands of tons per year.

The Ripple Effect

MiAlgae reached the Earthshot Prize finals in 2024, bringing attention to aquaculture's hidden sustainability problem. The recognition has opened doors with manufacturers looking for alternatives to wild fish ingredients.

Martin acknowledges they're still small compared to global demand. "In the omega-3 world that's a good start, but a drop in the bucket," he says. "So we've got lots more fish to save still."

As commercial production scales up, MiAlgae is proving that industrial waste from one beloved Scottish tradition can help protect ocean ecosystems for future generations.