Subsidence and rising sea levels threaten Venice. The ‘Mose’ project can save the city, but will damage the lagoon environment.
Venice Italy is Sinking
A combination of rising sea levels and the steady sinking of a few centimeters every year means that the wonderful architecture of the city is under serious threat. Venice now floods more than one hundred times a year, compared with a century ago when it only flooded ten times a year. Urgent work is underway to protect the city from the rising water.
Venice Italy Mose Project
A huge structure (composed of 79 steel dams) is being strung from thousands of steel stakes where the floodwaters enter the lagoon from the Adriatic Sea. These dams are each 30 meters high and 20 long, and they will be raised into position every time a high tide threatens the city. The project is expected to cost in excess of 5 billion Euros, with annual maintenance at about 9 million Euros after completion in 2013. Obviously the intention is to hold back the water – but there is concern about the effect this will have on the fragile ecosystem.
Effects on Lagoon Ecology
- There has been one unexpected benefit from the construction of the flood barrier. It is providing an excellent habitat for sessile organisms, and there are now corals growing alongside other animals and plants usually found further south in the Mediterranean. This is thought to be due to the protection afforded by the structure, aided by the gradual warming of the sea due to climate changes.
- At the moment (before the barrier is complete) there is little interference with the natural circulation of water between the Adriatic and the Lagoon, but there are serious concerns over the effect the completed barrier will have. The lagoon could eventually become a huge stagnant pool!
In an effort to control the effect that encrusting (fouling) organisms such as mollusks and barnacles would have on the structure it is intended to use an anodic protection system. This would slowly release zinc into the water. Zinc accumulates in the environment and there are serious concerns for the future of the mollusk farming in the area. The ecosystem will certainly be affected, and the traditional fresh seafood menus of Venice might well disappear.
Architecture Versus Wildlife
There seems to be a very stark choice to be made here. Either the wonderful architecture of Venice is saved for the time-being, or the lagoon environment is allowed to thrive at the expense of the city. Venice is a major tourist attraction at the moment, but would it remain so if the buildings were crumbling further and the tourists had to do all their sightseeing by boat? Would Venice still retain its attractiveness if the architecture survived but it was surrounded by a stagnant lagoon and cut in half by a smelly Grand Canal? There is also the risk of losing the incredible locally-fished seafood dishes which many visitors (including the writer of this article!) adore. This is a difficult choice for the Venetians.
(See also: 'Marine Aquarium in Venice' and 'Venice Floods and the Controversial Moses Project')
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