Human Controlled Wetland Project for Carbon Capture and Storage in the Venetian Lagoon, Italy

Greenhouse gas sink projects in lagoon environments are unlikely to generate carbon credits for the voluntary market, using current methodologies and standards such as VCS, Gold Standard etc. Now, thanks to new PdR UNI 99:2021 (Italian Organization for Standardization) and the Italian National methodology “BNeutral'', the sink of greenhouse gas CO2 in a human controlled Italian lagoon (Human Controlled Wetland or “valle da pesca”) can generate carbon credits for the voluntary carbon offset market. Twelve H.C.W. “valle da pesca'' has performed the project from 2013 in 4 different locations inside and outside the Venetian Lagoon. These places are located in the Italian Venetian Lagoon (UNESCO preserved area), in the Grado Lagoon, and in Comacchio Lagoon, all based in North Italy, Europe. The CO2 sink is regulated by the balance of autotrophic and heterotrophic activities. The sediment, with a very active anoxic denitrification and the benthic macroalgae production are basic tanks of CO2 in the wetland shallow waters. A multi-parameter chemical and biological approach has been issued. Data is recorded once a day for 364 days by a personalized continuous electronic device data logger installed inside the lagoon. A reduced light supply due to high turbidity caused by 1) natural meteo anomalies or bird/fish feeding, 2) fresh water inlet 3) low presence of algae, can reduce the carbon sink and the carbon credit generation. The H.C.W. have a surface range from 100 to 2.000 ha and a sink range from 5 to 25 kg of CO2 /m2 per year.