Healthy, convenient and increasingly popular over the past few years, sushi has become as common a cuisine in the UK as Indian or Chinese.

It’s a staple lunch-choice for city-workers all over the country and you’re never far from a restaurant or supermarket selling the traditional Japanese delicacy.

But it turns out sushi may not be as wholesome a choice as we previously thought – leading biologists have warned that it is in fact harming both the environment and our health.

The UK sushi market is worth £69m a year, but because we’re eating so much of it, tuna supplies in the oceans are dwindling.

According to Professor Daniel Pauly and Dr Dirk Zeller, the leaders of the Sea Around Us project at the University of British Columbia, bluefin and yellowfin tuna populations have reached “crisis” levels.

Bluefin tuna tends to be served in high-end, luxury sushi restaurants, whereas yellowfin is more common in high-street sushi bars and supermarkets.

Increasing global demand means sushi populations are being overfished. Most of the UK’s sushi comes from the Indian Ocean, but according to Professor Pauly we now only have 2-3 per cent of what we had 200 years ago.

“We are in permanent crisis if you look at it in historic terms,” he warned.

Sushi 3D nail art Show all 8 1 /8 Sushi 3D nail art Sushi 3D nail art Sushi nail art Copyright: Twitter/eri0128_as Sushi 3D nail art Sushi nail art Copyright: Twitter/mqmx666 Sushi 3D nail art Sushi nail art Copyright: Twitter/mqmx666 Sushi 3D nail art Sushi nail art Copyright: Twitter/masumi0827 Sushi 3D nail art Sushi nail art Copyright: Twitter/masumi0827 Sushi 3D nail art Sushi nail art Copyright: Twitter/karaagetabeta Sushi 3D nail art Sushi nail art Copyright: Twitter/kyo22po Sushi 3D nail art Sushi nail art Copyright: Twitter/mqmx666

Professor Pauly and Dr Zeller believe it is our love of healthy tuna that’s causing the problems in our oceans.

The fish is popular not just for its taste but for its health benefits – it is rich in omega-3 fatty acids, which aid heart health.

But whilst sushi has a reputation for being low in calories and high in nutrients, we may have overestimated its health value.

In advance of a lecture at the Zoological Society of London last night, Professor Pauly revealed he believes most high-street restaurants serve sushi that contains plastic microbeads, the controversial tiny particles often found in face-scrubs and beauty products.

“Microbeads are poison pills which soak up all the pollutants and they are consumed by little fish which are then eaten by tuna,” Professor Pauly explained to the Mail Online.

What’s more, according to Dr Zeller, sushi often contains high levels of mercury and polychlorinated biphenyls, which are chlorine compounds found in waterways that have been linked to causing cancer.