Effects of Nitrogen Emissions on Fish Species' Richness across the World’s Freshwater Ecoregions
The increasing application of synthetic fertiliser has tripled nitrogen (N) inputs over the twentieth century. N enrichment decreases water quality and threatens aquatic species such as fish through eutrophication and toxicity. However, the impacts of N on freshwater ecosystems are typically neglected in life cycle assessments (LCA). Due to the variety of environmental conditions and species compositions, the response of species to N emissions differs among ecoregions, requiring a regionalised effect assessment.
This study approaches this issue by establishing regionalised species' sensitivity distributions (SSDs) of freshwater fish against N concentrations for 367 ecoregions and 48 combinations of realms and major habitat types globally. Subsequently, effect factors (EFs) were derived for LCA to assess the effects of N on fish species richness at a 0.5 degree × 0.5 degree resolution. Results show good SSD fits for all of the ecoregions that contain sufficient data and similar patterns for average and marginal EFs. The SSDs highlight strong effects on species richness due to high N concentrations in the tropical zone and the vulnerability of cold regions. This study reveals the regional differences in sensitivities of freshwater ecosystems against N content in great spatial detail and can be used to assess nutrient-induced impacts in LCA more precisely and comprehensively.
Authors
Specifications
- Publication title
- Effects of Nitrogen Emissions on Fish Species Richness across the World’s Freshwater Ecoregions
- Publication date
- 22 May 2023
- Publication type
- Article
- Publication language
- English
- Magazine
- Environmental Science and technology
- Issue
- 57, 22
- Product number
- 5376
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