Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

Article English OPEN
Mo Shuqing ; Zhang Xiufeng ; Tang Yali ; Liu Zhengwen ; Kettridge Nicholas (2017)
  • Publisher: EDP Sciences
  • Journal: Knowledge and Management of Aquatic Ecosystems (issn: 1961-9502)
  • Related identifiers: doi: 10.1051/kmae/2017034
  • Subject: snail | SH1-691 | coexistence | submerged plant | benthic algae | planktonic algae | Aquaculture. Fisheries. Angling
    mesheuropmc: food and beverages | fungi

Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails) were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN), total phosphorus (TP) and chlorophyll a (Chl a) concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.
Share - Bookmark