An exceptional and fragile biodiversity
In addition to the city of Venice, the Unesco World Heritage Site also includes the lagoon and its man-made natural environments. More than 70,000 hectares of the lagoon are of ecological interest, notably as breeding grounds or habitats for some 200 species of migratory and sedentary birds. Biodiversity is characteristic of wetlands: canals, marshes, islands, lais and river mouths. The lagoon is home to populations of redshanks, terns, avocets, little egrets and shelducks. As for aquatic species, the lagoon is home to various fish populations, whose diversity is steadily diminishing as a result of the various pollutants affecting the site, and overfishing. The lagoon's flora is also remarkable: for example, Venetian glasswort can be found in the lagoons, and sea rush in the less brackish waters.
Gardens and natural spaces
When it comes to green spaces, Venice and its lagoon will delight lovers of nature and tranquillity. The city boasts numerous public and private gardens, some of which are open to visitors. The garden of the Carmes Déchaux Fathers, for example, is hidden from view and comprises various parterres (orchard, vegetable garden, medicinal garden, vineyard, "mystic" garden). Among the public parks, the Napoleonic Gardens or Biennale Gardens, built in the 19th century, offer a place to stroll and relax along the south bank of the Castello district. Other, more intimate gardens offer charming havens of peace, such as the Papadopoli Gardens, the Villa Groggia Park and its romantic ruins, the Parco delle Rimembranze, under pine trees and along the water's edge, and the Savorgnan Gardens. Private gardens include palace gardens: Cappello Malipiero Barnabò, Malcanton, Nani, Zenobio, Contarini dal Zaffo, Soranzo Cappello, Gradenigo; and the Ca' Tron garden within a university, or the garden of the Cloister of San Francesco della Vigna. Other places outside the city are ideal for discovering biodiversity, such as Lido Island, with its long beach. Less frequented, we recommend a visit to the Ca'Roman nature reserve, accessible by footpath from the southern end of the island of Pellestrina.
Flood risk and mitigation projects
Is Venice definitively doomed by rising sea levels? One thing is certain: the rising waters have been increasing for several centuries. It is linked to the geological and geographical nature of the site, which is subject to two mechanisms: eustasy on the one hand, i.e. variation in sea level, and subsidence on the other, which means the subsidence of the ground. The phenomenon is amplified by global warming. Add to this the winds - the bora and the sirocco - which accentuate flooding during acque alte, and extreme events are the result. This is precisely what happened in November 2019, when a terrible autumnal acqua alta flooded a large part of the city. Solutions to slow down this type of phenomenon now rely primarily on the MoSe (MOdulo Sperimentale Elettromeccanico), a 20-year project that is finally operational. This artificial dam is made up of 78 gates distributed over four barriers across the lagoon's channels. It is programmed to rise with every tide predicted to exceed 1.10 metres. Other solutions have been put forward to reduce the risk of flooding in Venice, such as the restoration or recreation of certain degraded natural areas, which would allow a better distribution of water in the lagoon. Another idea put forward was to modify the course of certain rivers, which had previously been diverted, in order to return them to the lagoon and generate a sediment supply.
Anthropogenic risks
All human activities have the effect of weakening biodiversity and the city itself: intensive farming upstream, overfishing, industrial activities, mass tourism, etc. These activities have also led to pollution.
In particular, they have generated pollution: pollution linked to pesticide-laden agricultural water, and aqueous and atmospheric discharges from industrial activities. For example, the Porto Marghera petrochemical plant, now closed, discharges several thousand tonnes of toxic effluent and sludge into the lagoon and Adriatic Sea every year.
Mass tourism: a real risk
Mass tourism exerts considerable pressure on the environment and causes numerous nuisances for local residents. The millions of visitors every year have an impact in terms of drinking water consumption and treatment, energy consumption, waste generation and traffic in the city. The carbon footprint of visitors (particularly in terms of transport) is also an issue. The question of cruise ships has become a highly sensitive issue, particularly since a cruise ship collided heavily with a Venetian quay in 2019. Since 2021, ships over 25,000 tons are no longer welcome, particularly on the Giudecca Canal. They are invited to sail further back in the lagoon. The municipality has also recently taken an even more drastic and comprehensive measure to control the risks associated with mass tourism. Starting in 2025, it plans to introduce a €5 visitor's tax at the entrance to the city for all "day" visitors (not just cruise passengers), with a test phase in 2024 running from April 25 to July 14 for daily tourists.
Towards the sustainable city
A number of initiatives have recently been launched to make the city more liveable and "sustainable". Slow tourism" initiatives have been developed, such as the closure of certain streets to tourists, to contain traffic flows in the city. The range of organic products on offer is growing, and a Sustainable Tourism Charter for the North Lagoon of Venice promotes eco-responsible tourist activities. Finally, efforts are being made in waste management, water effluent treatment and the redevelopment of brownfield sites. Time will tell whether all these measures are effective. It's up to the various players to contribute to environmental protection.
