Around 150,000 baby octopuses have been released off the coast of Italy to help stop invasive blue crabs from destroying local marine life.
The blue crab is originally from the Atlantic coast of America. In recent years, its numbers have surged along the Italian coast, especially in the Emilia-Romagna region. These aggressive crabs eat native shellfish like clams and mussels, causing serious harm to local ecosystems. Since 2022, the blue crab invasion has cost the regional fishing industry around £14.7 million.
To tackle the problem, aquaculture researchers Oliviero Mordenti and Antonio Casalini from the University of Bologna looked for natural solutions. Local fishers had noticed that common octopuses eat blue crabs. Laboratory tests confirmed this observation, showing that a single octopus can eat up to four blue crabs a day.
The researchers caught four male and four female octopuses from the local coast and kept them in special tanks that simulated ocean conditions. After the octopuses mated, the scientists collected 150,000 tiny larvae, each just one millimeter long. On August 24, they released the young octopuses into the waters near the coastal towns of Cesenatico and Riccione.
Because baby octopuses are very small and often eaten by fish, scientists estimate that only about one percent will survive to adulthood. However, even young octopuses weighing less than 800 grams are strong enough to hunt blue crabs. The regional government has also placed artificial shelters on the sandy seabed to give the octopuses safe places to live.
Scientists will work with local fishers to track the results until the end of the year. Some experts urge caution, pointing out that blue crabs grow very fast and prefer different habitats than octopuses. Releasing young larvae into the open ocean is a pilot experiment, but researchers hope it will boost native marine populations and protect local fisheries.