Crabs are a contentious topic in Venice right now. The moeche, or soft-shell crabs - normally harvested from lagoon mudflats to star on local menus for a few short weeks in October and April - have all but vanished this year.

It’s blamed on a combination of rising temperatures, overfishing and invasive alien species – chiefly, the far larger Atlantic blue crabs, which have no natural predator here in the Adriatic. Populations of jellyfish and bluefish are similarly exploding in the warmer waters.