1 / 3

Venice Lagoon case study: The Problem

Venice Lagoon case study: The Problem. 1960s and 1970s Uncontrolled discharge of nutrients 1980s Hypereutrophic conditions Macroalgal density = 20 kg FW m-² loss of SAV beds and change in species abundance Severe anoxia in parts of the lagoon. Dissolved Oxygen 2004-2005.

dai
Download Presentation

Venice Lagoon case study: The Problem

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Venice Lagoon case study: The Problem 1960s and 1970s Uncontrolled discharge of nutrients 1980s Hypereutrophic conditions Macroalgal density = 20 kg FW m-² loss of SAV beds and change in species abundance Severe anoxia in parts of the lagoon

  2. Dissolved Oxygen 2004-2005 SAV distribution 2002 Venice Lagoon case study: The Solution • 1980s • Wastewater treatment plants (WWTP) built • P banned from detergents • 1990s to present • Decrease in nutrient loads and P concentrations • Macroalgae density now 0.5 FW m-² • SAV beds returning - since 1992: • Zostera marina increased (2.6 – 22 km²) • but Nanozostera noltii decreased (14 – 0.7 km²) • No anoxia – DO at 40% saturation, adequate for aquatic life • Future • New WWTP and phytodepuration plants planned • Industrial zone effluents closely monitored • Continued improvement expected

  3. Venice LagoonASSETS Application (early 2000s) ASSETS: HIGH Indices Overall Human Influence (OHI) ASSETS: 3 Overall Eutrophic Condition (OEC) ASSETS: 5 Determination of Future Outlook (DFO) ASSETS: 4 Methods Susceptibility Nutrient inputs Primary Secondary Future nutrient pressures Index Moderate LOW Improve Low Parameters Rating Expression Dilution potential Low High susceptibility Flushing potential Low High Chlorophyll a Low Low Macroalgae Low Dissolved Oxygen Low Submerged Aquatic Low Vegetation Low Nuisance and Toxic Low Blooms Future nutrient pressures decrease http://www.eutro.org/

More Related