‘Like a maternity ward’: how massaging fish can produce ‘no-kill caviar’
Killing critically endangered sturgeon to extract their eggs is not only unethical but unnecessary, say advocates of a more sustainable method
The turning point for polar and marine scientist Angela Köhler came in 2005, when she attended a demonstration on caviar production in the Caspian Sea. Bringing out a two-metre female sturgeon in front of 150 conference guests, the caviar master beat the fish on the head to death before cutting its belly open. “The masters suddenly became extremely nervous,” she recalls. “They went on to say that the eggs were too close to spawning and so they couldn’t use them as caviar. They discarded the entire fish and began the process again with a new one.”
The brutality of the moment is something Köhler still remembers. As an expert in environmental toxicology, she was at the conference to study the damage to sturgeon populations and the Caspian Sea caused by chemical pollution. But the experience set her on a new mission: to find a way to produce “no-kill” caviar.
“I thought it must be possible to protect such valuable animals. Surely, you can just strip eggs from the body and the fish can live on,” she says. Depending on the species of sturgeon, the fish do not start spawning for a minimum of eight to 15 years. “Killing them for their eggs after farming them for all of those years is just economically insane,” says Köhler.
Working for the scientific research company Alfred Wegener Institute (AWI), Köhler spent four years developing a way to stabilise the eggs. An ultrasound is carried out to check the eggs are ready and then the bellies of the fish are gently massaged so that they are naturally released.
Extracting the eggs without killing the fish is not just an ethical issue. Sturgeon are one of the most critically endangered species on the planet due to overfishing and poaching for the illegal trade in wild-caught caviar and meat. An IUCN assessment of the species in 2022 found all 26 species are threatened with extinction.
Originating more than 200m years ago, these prehistoric creatures can live to over 100, grow to seven metres long, and weigh up to 1.5 tonnes. They are the only species that produces traditional caviar, which can only legally be taken from farmed fish.
Farms in the UK, California, Iceland, Sweden and Germany have a licence from AWI to produce caviar using Köhler’s technique. Köhler now has her own company, Akazie, which acts as a general consultant for the licensees. “We visit the farms and have a look at whether they are candidates for an AWI licence. We also give advice on how to install a caviar lab, apply the patented processes and train the staff.”
The Addeys got in touch with AWI. After 10 months of drawing up contracts and undergoing checks on their farm, their company, KC Caviar, was awarded a licence to start making no-kill caviar and did so for 10 years.
John describes the process of extracting the eggs from live fish as like working in a maternity ward. “We massage the tummy and make sure it’s really soft. If it’s too hard, we place them back in the water. If the tummy is soft, the eggs will naturally release when you press the belly. We then take them to get stabilised in a lab.”
The family are now raising a new generation of sturgeon, which will take eight years to mature.
Deborah Keane, a no-kill caviar farmer from California, founded her business, the California Caviar Company, in 2007. Today, she has about 20,000 sturgeon and supplies a number of exclusive restaurants. Some of the chefs have been known to get into the water and swim with the fish, hand selecting which sturgeon they would like to nurture for their eggs.
Before she started the business, Keane regularly ate caviar but was concerned about the sustainability of the industry. She partnered with AWI in 2012.
