Mafia mussel: the fight to save a mollusc from the mob

As poaching of date mussels wrecks Naples' reefs, police joined biologists to find the gangs behind it

After a three-year investigation into two organised crime groups in Italy's Campania region that included wire taps, surveillance and nearly 100 suspects, police cracked down with a dozen arrests in March - not for offences linked to drugs or prostitution, but for the illegal harvesting of a small mollusc.

Known as date mussels, Lithophaga lithophaga are cigar-shaped shellfish that make their homes inside limestone, secreting an acid that slowly carves out a tunnel in the rock. They take decades to grow - anywhere from 18 to 36 years to reach just 5cm in length - and can live for more than 50 years.