Mobile barriers collectively known as the Moses project are under construction across three channels accessing the Venice lagoon to protect the city's churches and piazzas from flood tides. Two of the barriers, which rise from the sea bed at high water, are protected by breakwaters which have inadvertently given Venice an instant barrier reef that boasts 150 species of fish, sea creatures and colourful algae.
"There are people already showing up to dive and I envisage tourists coming to Venice to see the canals before indulging in a spot of scuba diving," said marine biologist Andrea Rismondo.
Cuttlefish, starfish, crabs, jellyfish, molluscs measuring 30cm (1ft) and 50 types of fish are now making a home among the sponges and tree-like Cystoseira algae, which grow to 1.5m (5ft) in height along the rocky breakwaters stretching nearly a mile in water up to 14 metres deep.
"It is mostly sandy around here, so the breakwaters were a real chance for sea life to set up, but we were still surprised by the numbers," said Rismondo. "One hypothesis is that warmer water here due to climate change has helped."
The project, which has been contested by environmentalists, who fear for the lagoon's fragile eco-system, could now be turned into a marine park.
