The cultural, economic and environmental facets of Venice have come to be more and more in competition with each other: what is palliated on one side becomes a disadvantage to another. This conflict of interests within a same organism makes for a baffling panorama of contradictions.

Northwestern part of the lagoon,
usually unknown to tourists
BY Stephanie Sears

Mauro Bon of the Museo di Storia Naturale reports that levels of dioxin and diesel in both air and water are high and that historical Venice suffers particularly from the sulfur emanating from fossil fuel. During summer the whole lagoon is negatively affected by the circulation of thousands of boats; yet new menaces loom ahead. One is a project to enlarge the existing port’s capacity that already receives three hundred meter ships like the Emerald Princess cruise liner. This project, according to Mauro Bon, goes against common sense when one considers the damage already caused by ships in the Canale dei Petroli, a main passageway leading to and from the Malamocco entrance where levels of pollution are high and ship waves erode the barene.

During a field trip with the ISMAR marine geologist Luca Zaggia and his team, our two boats are anchored one behind the other, aligned with the incoming current between the Lido and Cavallino barrier islands. Nearby, the MOSE work in progress shows its impressive proportions. The goal of the research coordinated by Corila (Consorzio Ricercha Laguna) is to determine the effect of the MOSE dredging and construction on water quality, and how already in-place submerged structures affect hydrodynamics and transference of sediment. An Acoustic Doppler Current Profiler and a Laser In Situ Scattering and Transmissometry (Lisst100x) respectively measure the speed and direction of the current, the amount of the sediment transported and the grain size. On the other boat the more grueling and tedious task of plunging, retrieving and emptying “sediment traps” (bags), at regular intervals, capture the bed load in order to identify the weight of the sediment, its grain size and the organic matter content.

A later field trip with ISMAR biologist Davide Tagliapietra serves to determine the conditions that favor, or not, the small but destructive Teredini bivalve that eats into the wood piles or bricole that stud the lagoon to signal the navigable channels. Once inside the wood the mollusk stretches out of its shell and worm-like eats its way right through the bricole. In parts of the lagoon plastic piles have begun to replace the traditional ones which Davide hopes to save and reinstate through his research. It becomes nonetheless evident that the lagoon has already other prosthetic replacements, namely artificial barene and reinforcements around natural ones.

A half-submerged hunter’s cache on a small barene
BY Stephanie Sears

The lagoon also gradually shows itself to be an open scientific laboratory where high tech artifacts appear like alien objects dropped from space such as the odd R2-D2-like current monitors on stilts (Centralina multiparametrica per le acque servizio antinguinamento del magistrato alle acque), and trihedral corner reflectors planted on mudflats receiving radar signals that measure the degree of subsidence of the lagoon floor.

Further northwest, the lagoon seems almost left to itself. Sea lavender is blooming and among the reeds appear graceful white egrets and motionless Grey Herons. Migrating Cormorants, going east, form myriad geometries in the pellucid sky. Large square nets hang over our heads like festive canopies and an occasional fisherman in his small boat plies his hand net through the water amidst an extraordinary quietude. Thanks to the flow of the Dese river through this part of the lagoon, the water is meschizza, in other words, a fluctuating mixture of fresh and salt water which endemic flora thrives on; as do the birds that suddenly seem more numerous in contrast with other parts of the lagoon where this brackish mixture is mostly replaced by sea water.

The best-preserved areas in the lagoon, according to Davide, are the privately-owned valli di pesca or fish farming areas concentrated in the north and south west of the lagoon next to the mainland. They extend over 9000 hectares of the whole lagoon surface and serve to capture young fish migrating inland from the sea in spring. A more centralized management than in the rest of the lagoon has better preserved nature in these areas and offers a more favorable terrain for a burgeoning eco-tourism.