Italy releases 130,000 octopuses to combat invasive blue crab population
Quick Look
- Italy has released 130,000 captive-bred octopuses along the Emilia-Romagna coast to control an invasive blue crab population that has devastated fisheries and caused an estimated £170 million in damage.
- The initiative, led by University of Bologna researchers, is described as experimental, with early signs showing sub-adult octopuses preying on blue crabs.
AI-generated summary
Why It Matters
Blue crabs, native to the North American Atlantic, were likely introduced to Italian waters via ship ballast water decades ago. Their population has grown due to climate change warming sea temperatures, leading to severe damage to fisheries, nets, and shellfish stocks.
An army of octopus have been released in Italian waters to tackle a destructive influx of blue crabs.
The invasive crustaceans are thought to have been accidentally introduced to the Adriatic coast decades ago after travelling long distances in ships’ ballast water.
Blue crabs, which originate from the North American Atlantic Ocean, have destroyed Italy’s fishing industry. The blue-clawed critters wreck fishing nets and have eaten eel, clam and mussel stocks, causing an estimated damage of £170million.
The government has previously been encouraged to declare a state of emergency over the invasion and attempts to manage the situation have not been successful.
But now, a “formidable predator” has been introduced to the coast along Emilia-Romagna, one of the hardest hit regions in Italy.
Bred in captivity by scientists from the University of Bologna, 130,000 baby octopuses (Octopus vulgaris) have been released to tackle the mushrooming blue crab population, which typically has few natural predators.
Antonio Casalini, one of the researchers on the Octo-Blu initiative, told AFP: “We chose the octopus because, in the wild, it is a formidable predator of crustaceans.”
Another researcher Laura Gentile told The Independent the programme is an “experimental measure” and “not a solution” to the problem.
But she said: “We've also seen sub-adult octopuses actively going after blue crabs, including some fairly large ones, around 400 to 500 grams.
“That's an encouraging sign biologically, and it's what gave us the confidence to move to field trials.”
It’s hoped an adult octopus could eat up to four crabs a day.
The exact number of crabs across Italian coastlines is unknown, but it’s thought to be in the millions. A female blue crab can lay up to two million eggs a day, most of which hatch, according to the National Wildlife Federation.
Climate change has pushed up sea water temperatures, which caused the blue crab population to explode a few years ago.
Gentile said the team is researching other initiatives to tackle the invasion, including harvesting blue crab eggs and using them to feed European eels.
What to Watch
AI outlook — possibilities, not facts
If sub-adult octopuses continue to prey on blue crabs, field trials may expand to other affected regions.
Likely · Within months
Research into harvesting blue crab eggs to feed European eels may proceed as a complementary control measure.
Possible · Within months
Open Questions
- What is the exact current population of blue crabs along Italian coasts?
- How will the long-term ecological impact of introducing large numbers of octopuses be monitored?
- Are there risks to native species from the octopus release?
- What is the survival rate of the released juvenile octopuses in the wild?
