Italy releases young octopuses into Adriatic Sea to control blue crabs

 An invasive species of blue crab is threatening Italian fisheries, and to deal with it, the country has opted for an unusual solution: releasing thousands of young octopuses into the Adriatic Sea.

 

According to Scientific American, around 130,000 common octopus paralarvae, or newly hatched octopuses, have been released into waters off Italy as part of a project aimed at controlling the growing population of invasive blue crabs.

 

While blue crabs are a prized seafood species in the mid-Atlantic region of the US, they are considered invasive elsewhere. The crabs were first spotted in the Mediterranean Sea in the last century, but their population surged about a decade ago, threatening native biodiversity and the fishing industry.

 

 

The project, called Octo-Blu, is being led by researchers at the University of Bologna in collaboration with the Emilia-Romagna regional government.

 

The tiny octopuses are only a few millimetres long when released. If they survive and grow into adults, researchers hope they will help control the blue crab population. Under suitable conditions, a one-kilogram common octopus can eat up to four medium-sized blue crabs a day.

 

However, the project comes with a major uncertainty: most octopus paralarvae do not survive long enough to become adults.

 

Gianluca Sarà, a marine ecologist who is not involved in the project, said the idea behind it is “great”, but its impact could be “absolutely negligible”, Scientific American reported. Sarà said octopus paralarvae have a mortality rate of around 99.9 per cent, meaning only a small fraction of the released animals could eventually become predators of the invasive crabs.

 

Researchers do not expect octopuses to eliminate blue crabs from the sea. Antonio Casalini, an aquaculture research technician involved in the project, said, “We are not introducing a new species but working on strengthening the population of a native species already naturally present in the Adriatic,” according to Scientific American.

 

The researchers chose the common octopus because it is hardy and reproduces quickly, with females capable of producing hundreds of thousands of eggs. The team plans to release more paralarvae as they produce them, but the results of the project will only become clear in the long term, according to Scientific American.

 

The aim is not to eliminate blue crabs from the Adriatic Sea, but to help control their population alongside other measures, including existing fishing efforts. Whether the young octopuses can survive in sufficient numbers to make a difference remains to be seen.