Five facts you need to know about the Lagoon of Venice
Aquatic and green: sea moss, twisting vines, saltwater, driftwood. This could be your first impression when you visit the islands in the Lagoon. But la Laguna Veneta - the Lagoon of Venice is so much more than a hidden cove of calm water (yet quite large!) warmed by the sun and sprinkled by lush greenery, the secret world of the famous, lesser-known, and forgotten islands.
Just imagine - your plane is landing at the Venice Marco Polo airport, located on the northern edge of the estuary, and the Lagoon is coming in sight. Depending on the weather you’ll make out various shades of color patterns:
Light blue and azure. Deep blue and marron. Olive and emerald-green. Call it ecomosaico – a mosaic of life making up the various ecosystems of the largest lagoon of the Mediterranean Sea. It’s actually 550 km² in size!
But did you know that it’s not just one Lagoon but actually two, and that they differ from each other considerably? The southern Lagoon is roughly 5000 years old and is called Laguna Viva. The northern Lagoon Laguna Morta was created later, when the sea level rose further around 1500 BC, submerging additional parts of the coastal plain.
And these differences have been visible ever since humans have settled in the Lagoon. The southern Lagoon has always been deeper and flushed with salt water. The northern part of the Lagoon has always been described as more shallow, where a long time ago, large saline (salt pans) were located just south of the island Burano, and the water was less saline as the rivers discharged huge amounts of debris and fresh water.
And now, we’ll let you into five secrets about the Lagoon:
#1 You can learn to read its colors, and thus its history
Taking a look at the Lagoon from above, you can make out large brown areas called barene (mudbanks). Barene are exposed to the tides, and often the home of sea lavender (limonium).
Green patches mean islands, deep blue means deep water (man-made shipping canals), and turquoise-maroon means shallow water (bassi fondali).
You can all see it in the image above! PS - I suggest we return to this image more often, and give further explanations about the ecosystem of the Lagoon. Actually, it contains a lot of information that we could also write a book about :-)
The city of Venice (centro storico) built on 118 islands at the geographical center of the Lagoon represents the border between these two Lagoon habitats, the northern and southern Lagoon, and also functions as watershed where sea and fresh water meet.
But then, the northern Lagoon called Laguna Morta doesn’t mean that this stretch water is dead. On the contrary, it’s the part less exposed to sea water and that’s why it’s always been used for extensive vegetable farming.
This area was given the name Laguna Morta by the engineers of the Republic of Venice, who 500 years ago fought the opposite problem that we have today:
The Lagoon turned very swampy and was in danger of disappearing in huge amounts of muds. People left the islands Torcello, Ariano and Santa Cristina due to malaria-carrying mosquitoes. The government of Venice had to act, and dams were built to change the direction of the rivers discharing debris into the Lagoon (Brenta, Sile, Adige). From that time, the picture has changed completely and the Lagoon must be monitored closely to prevent it turning into open sea.
#2 The barene (muddy sandbanks) are very much alive!
If you look closely, you can notice that the brown areas in the Lagoon, those sand and mudbanks I mentioned above, take on a purple color in late summer when sea lavender (limonium) is in bloom. In fact, almost one third of the shallow northern Lagoon, between Torcello and Treporto, towards the swamps of Jesolo is covered by sea lavender which blossoms from mid-July to late September, and sometimes early October.
#3 Venice won’t sink because the barene protect it
Now that’s a statement, but we’ll explain in a minute: The phenomenon called subsidenza (slowly sinking parts of the Lagoon, and of Venice) was slowed down considerably in the early 1990s when the industry facilities in Marghera stopped pumping freshwater from under the Lagoon. So Venice won’t sink because le falde acquifere (groundwater) isn’t disturbed any more by the industrial facilities, and also because exploiting natural gas has been stopped for good. Yet, the myth of the sinking city has endured to this day!
Of course, a very slight movement in the soil is always present as the weight of the buildings presses onto the islands whose soil becomes more compact as time is passing by.
The real danger for Venice is not that the city is sinking but actually the change in climate patterns. With sea levels rising overally, Venice is in danger (1) in case the sea level rises considerably due to climate change and (!) (2) additional barene are damaged by erosion.
So you can see, again, it’s the barene that help out Venice, by acting as a swamp around the islands, and soaking up excess waters. This system of Barene has also been used to defend the city of Venice from invaders coming from the sea:
While the northern Lagoon has always been very shallow by nature, during the times of the Republic, the engineers worked hard to create a sort of protecting line of barene with shallow canals around the inlets of the Lagoon. That’s been for a reason, to be able to prevent large enemy ships from entering the Lagoon.
I love this video by Francesco da Mosto showing how shallow the Lagoon really is, and how these unexpectedly shallow waters helped defend Venice from invaders for centuries - their ships would get stuck in the mud.
#4 The Lagoon is already a perfect “natural waterway” consisting of artificially made landscapes
Natural canals and submerged river beds are called ghebi and can be reached only by flat boats called sandali. There are these shallow canals also to prevent the islands from flooding - broad deep water canals, deep enough for oil tankers and cruiseships to pass, bring on huge amounts of water, and are the main reason for acqua alta these days!
The Lagoon was “sculpted” by the wise engineers of the Republic of Venice, and today is a paradise for growing herbs, wine and vegetables in the north (Laguna morta, with more fresh water), and fishfarming and catching vongole in the southern parts called Laguna viva.
Actually, there’s a wonderful stretch of fertile marshlands just east of the island Torcello towards the Cavallino Peninsula and Treporti called Orto dei Dogi - the vegetable gardens of the Doges.
And the barene are also famous for another culinary specialty: Lagoon honey from the flowering plants growing on the barene. As we’ve been asked several times, if you’re in Venice, you can buy this honey called miele di limonium at specialty stores in town, for example at Casa del Parmigiano at the Rialto Market.
So the Lagoon is extremely diverse and colorful: There are even olive groves thriving in the mild and humid climate of the Lagoon, on Torcello and on the island Sacca Sessola. Vineyards have always grown on Mazzorbo, artichokes and green vegetables on Sant’Erasmo, Le Vignole and on Mazzorbetto in former times. Tomatoes grow on the Cavallino peninsula (read more in an upcoming post in July).
#5 The Lagoon thus is a pianura liquida - liquid plain studded with barene overgrown with plants that fulfill an essential purpose
Le barene fulfill an important function for the Lagoon to survive. (Edible) herbs growing there, such as limonium and salicornia, filter water much like plants filter water in a swimming pond, keeping the ecosystem in balance.
In the 17th century, 255 km² of the Lagoon surface were covered with barene, (more than half the Lagoon which is 550 km²). In 1901, barene-covered areas were 170 km² and in 2003, just 47 km² were left. So what has happened?
The barene are endangered by those wide man-made deep shipping canals in the Lagoon (Canale dei Petroli, Canale Vittorio Emanuele), through which strong currents can enter, causing the barene to erode.
So in the end, it’s all about restoring and keeping up the healthy balance in the Lagoon. There’s a part on the south-eastern edge where industry is located. There’s a part where food is grown. And there’s only a certain amount of ships that can be tolerated to enter the Lagoon.
A lot to be done, and a lot of information also needs to be shared with (potential) visitors. There’s a good chance that we can save the Lagoon and preserve what we have come to enjoy today: Like, the quiet summer colors of the island San Francesco del Deserto surrounded by barene overgrown with limonium. Harvesting salicornia that you can see in the image below, along the marshy canals in a wonderful vineyard garden called Venissa.
And did you know that pink flamingos have come to stay in the Laguna morta?