Eutrophication triggered changes in network structure and fluxes of the Comacchio Lagoon (Italy)

• Published in: PloS one Vol. 20; no. 1; p. e0313416
• Main Authors: Patonai, Katalin, Lanzoni, Mattia, Castaldelli, Giuseppe, Jordán, Ferenc, Gavioli, Anna
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.01.2025
• Subjects: Anthropogenic factors; Aquatic ecosystems; Biodiversity; Biology and Life Sciences; Biomass; Climate change; Coastal lagoons; Coastal management; Coastal resources; Coastal structures; Cyanobacteria; Cyanobacteria - physiology; Earth Sciences; Ecology and Environmental Sciences; Ecosystem; Ecosystem management; Ecosystem services; Ecosystems; Environmental changes; Environmental Monitoring - methods; Eutrophication; Fluxes; Food Chain; Food chains; Food webs; Forecasts and trends; Habitats; Influence; Invertebrates; Italy; Lagoons; Marine resources management; Medicine and Health Sciences; Natural resources; Network analysis; Nonnative species; Seawater; Submerged plants; Taxonomy; Vegetation; Italy; Adriatic Sea
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0313416

Coastal lagoons, which cover about 13% of coastline, are among the most productive ecosystems worldwide. However, they are subject to significant stressors, both natural and anthropogenic, which can alter ecosystem services and functioning and food web structure. In the Comacchio Lagoon (Northern Italy), eutrophication, among other minor factors, transformed the ecosystem in the early 1980s. Here, we compiled available data for the lagoon into trophic networks (pre- and post-transformation), analyzed the ecosystem using local and global network analysis, and computed trophic fluxes of the two periods. For comparability, the networks of two periods (i.e., pre- and post- transformation) were aggregated into food webs with 23 nodes. We found differences in the trophic networks before and after eutrophication, resulting in some decrease in complexity, increase of flow diversity, and an overall shortening of the food chain. A crucial aspect of this change is the disappearance of submerged vegetation in the lagoon and the increased importance of cyanobacteria in the post-eutrophication period. We provide an approach to better understand ecosystem changes after severe disturbances which can be extended to biodiversity conservation and for the management of coastal resources in general.