Originally published 2020-03-19.
In mid-March 2020, a few days after Italy shut down to slow the spread of Covid-19, photos of Venice's canals began racing around social media. The water, usually a cloudy green-brown churned by boats, looked glassy and see-through. You could spot small fish, weed on the canal floor and the stone edges of buildings disappearing into the water.
The short answer to why: the water was clearer, but not because it had suddenly become clean. With almost no motorboats, water taxis or delivery barges moving, the fine sediment that boat traffic normally stirs up was allowed to settle on the bottom. A spokesperson for the mayor's office explained it to CNN in exactly those terms, saying the water now looks clearer because there is less traffic on the canals, allowing the sediment to stay at the bottom.
That distinction matters, because some of the most shared posts from those weeks mixed a real change with a few things that were not true at all.
What actually changed in March 2020
Italy became the first European country to impose a national lockdown, in early March 2020. Venice, a city that normally welcomes an estimated 20 to 30 million visitors a year while fewer than 50,000 people live in its historic centre, went silent almost overnight. Cruise ships, tour groups and most commercial boat traffic stopped.
Venice's canals are shallow, and their beds are covered in soft silt. Every passing propeller and wake lifts that silt back into the water column, which is a big part of why the canals usually look murky. Take away the boats and the particles drift down. Light then reaches further, and things that were always there, such as small fish, crabs and seaweed, become visible from the bank.
Air quality also improved across northern Italy during the lockdown. Satellite measurements from the European Space Agency showed a sharp fall in nitrogen dioxide, a pollutant that comes mostly from traffic and industry, over the Po Valley in March 2020. That was a genuine side effect of fewer cars, factories and flights.
Clearer water is not the same as cleaner water
Transparency is only one measure of a waterway. Venice's canals also carry the city's wastewater, since much of the historic centre still has no modern sewer network and relies on septic tanks that drain into the lagoon. Stopping the boats did nothing to change that. And no one can judge bacteria levels, chemical pollution or oxygen content simply by looking at how transparent the water is.
So the honest version of the story is narrower than the viral one: fewer boats meant calmer, clearer water for a few weeks, and the fish that had been living in the canals all along were easier to see. It was a striking sight, but it was not proof that the lagoon had healed.
Images of the clear canals were shared widely in March 2020. With boat traffic halted, sunlight reached the canal floor and passers-by could watch fish and plant life near the walls.
The swans, dolphins and other viral claims
Alongside the genuine photos came several that did not show what people thought. National Geographic looked into the most popular ones and found:
- The "returning" swans were photographed on Burano, a small island in the Venice lagoon where swans are regular residents. They had not come back to the city's canals.
- The dolphins in a widely shared video were filmed at a port in Sardinia, hundreds of kilometres from Venice, where dolphins are not unusual.
- The clearer water was the one part of the story that held up, though for the sediment reason above.
One of the most liked tweets of the period, posted by a user in New Delhi, combined the clear water with the swan pictures. She later told National Geographic that she had put together photos she had seen online and did not know the swans lived on Burano anyway. Another tweet, from a user in Sardinia, listed several sightings at once, including dolphins in the port of Cagliari. That one is a good example of how a true local observation can blur into a bigger, less accurate story once it is shared out of context.
Boars in the middle of my hometown, dolphins in the port of Cagliari, ducks in the fountains in Rome, Venice canals have now clear water full of fishes. Air pollution dropped. Nature is reclaiming its spaces during quarantine in Italy. #COVID19 #COVIDー19 pic.twitter.com/dr6QILfF9V
— Francesco Delrio (@Cosodelirante) March 15, 2020
(This post is no longer available on X.)
Here's an unexpected side effect of the pandemic - the water's flowing through the canals of Venice is clear for the first time in forever. The fish are visible, the swans returned. pic.twitter.com/2egMGhJs7f
— Kaveri 🇮🇳 (@ikaveri) March 16, 2020
(This post is no longer available on X.)
Both tweets have since disappeared from X, but they show how quickly the "nature is healing" idea spread during the first weeks of lockdown.
Why "nature is healing" caught on
It is easy to see why people wanted these pictures to be true. In March 2020 the news was relentlessly frightening, Italy was one of the hardest-hit countries in the world, and millions of people were confined to their homes. A photo of a clear canal felt like a small piece of good news, and it fed a hopeful idea that the planet was recovering while humans stayed indoors.
The phrase "nature is healing" soon became an internet joke, with people posting obviously fake "returning wildlife" pictures. The joke worked precisely because so many earnest posts had overstated what was happening. Comments on Facebook at the time ranged from people suggesting an annual month-long lockdown to give nature a break, to others simply enjoying an unexpected bright spot.
The lesson is a useful one for any viral image: check where and when it was taken, and look for the simplest explanation. Animals that seem to "return" are often animals that were always nearby and are simply easier to notice when people are absent.
Quiet canals in central Venice during the lockdown. Photo credits as given with the original images: barnyz on Flickr and Venice photographer Marco Capovilla on Facebook.
What Venice did next
When tourists returned, so did the boats, and the canals went back to their usual colour. But the empty city sharpened a long-running debate about overtourism. In the following years Venice took several concrete steps:
- Cruise ships: from August 2021, ships over 25,000 tonnes were barred from the Giudecca Canal, keeping the biggest vessels away from St Mark's Basin.
- Flood defences: the MOSE barrier system, built to close the lagoon inlets during extreme tides, was raised for the first time on 3 October 2020, less than a year after a 1.87-metre flood in November 2019 covered most of the city.
- Day-tripper fee: a €5 entry charge for day visitors on peak days began on 25 April 2024, with exemptions for residents of the Veneto region, hotel guests, workers and students.
None of these measures will make the canals as clear as they were in spring 2020, because a working city needs boats. They do show, however, that the lockdown photos helped push a conversation about how many visitors and vessels the lagoon can realistically handle.
Myths and facts in brief
Myth: the canals became clean during lockdown. Fact: they became clearer because sediment settled; pollution sources such as wastewater did not stop.
Myth: dolphins swam into Venice. Fact: the famous dolphin footage came from Sardinia.
Myth: swans returned to the canals. Fact: the swan photos were taken on Burano, where swans already lived.
Fact: air pollution over northern Italy did drop measurably while traffic and industry were reduced.
Sources: National Geographic: fake animal news during the pandemic; CNN: Venice canals clear water; Wikipedia: Venice. Photos: barnyz (Flickr) and Marco Capovilla (Facebook).
COMMENTS