Last month fishermen off the North Yorkshire coast noticed something unusual. Their pots were not filled with brown crabs, but the huge, spindly-legged red king crab, a much-prized delicacy rarely seen off British shores. Chefs in London and elsewhere immediately snapped up the haul.

“We are excited, but a bit terrified,” Will Murray, head chef of London’s Fallow, told a newspaper. The fear was because the crab was thought to be an invasive species, introduced to Russia from the US in the 1960s. The giant crustacean has undertaken a slow march west, dubbed “Stalin’s red army”, devouring almost anything in its way. 

Except there was a further twist, as a team of scientists from the Natural History Museum analysed a sample and discovered it was, in fact, a native king crab, sometimes known as a prickly crab, and not an invader after all. The red king crab, says scientist Dr Paul Clark, hasn’t yet been seen south or west of Tromso in north Norway.

Yet, considering there are already so many invasive species (an introduced organism that dominates its new location, sometimes detrimentally) in the UK, from American signal crayfish to Japanese knotweed, both of which have been on the rise in recent years, it begs the question: should we be eating more of them? 

For many the answer is yes. Douglas McMaster, chef and owner at zero-waste restaurant Silo in London, says it fits into his environmentally minded ethos. “In an ideal world we would eat a lot of these invasive species. The word ‘invasive’ means they’re abundant.” 

McMaster believes eating them helps mitigate our carbon footprint, by replacing a farmed product with something bountiful in the wild. Next month, Silo is putting on a one-off invasive species dinner, centring on the much-hated Japanese knotweed and signal crayfish, both of which run rampant, damaging local flora and fauna.