Italian researchers and regional officials see octopuses as a natural way to ease a damaging blue-crab surge, while also promoting the crustacean as food. The shared objective is to protect fisheries, but the ecological experiment’s eventual effectiveness remains unproven.

Italy’s response to blue crabs is moving from fishing nets and supermarket counters into the sea itself: 130,000 newly hatched common octopuses have been released off Riccione and Cesenatico on the Adriatic coast.

The Octo-Blu project is intended to restore predation pressure on blue crabs, which have expanded along the coast after being introduced decades ago. Coldiretti, the agricultural organisation representing farmers and fishers, has put the damage to fishing and aquaculture at an estimated £170 million; reports say the crabs have torn nets and consumed clam and mussel stocks.¹

Officials portray the problem as both economic and ecological. Alessio Mammi, Emilia-Romagna’s agriculture and fisheries official, said: “The blue crab is not just an invasive species, it represents one of the most serious crises to have hit our waters.”² He said clam production has fallen by 70% in some areas, with some aquaculture businesses closing.¹

Researchers argue that octopuses offer a targeted natural predator. Bologna University’s Antonio Casalini said, “We chose the octopus because, in the wild, it is a formidable predator of crustaceans.”² Once mature, each could consume up to four crabs a day. Dr Oliviero Mordenti said removing even one female could matter because it may otherwise produce “1.5 million eggs, even two million.”¹

Yet the plan is a trial, not a guaranteed fix. One account puts hatchling mortality at 99%, potentially leaving only about 1,300 adults from the initial release.² Alongside further releases, authorities are encouraging consumption of blue crab, but reported demand has not yet substantially reduced its population.²