Rationale 2.6

Eutrophication is caused by excessive nutrient inputs (especially nitrogen and phosphorus) to water bodies and is a major environmental issue. It disrupts freshwater and marine ecosystems, contributes to algal blooms and oxygen depletion, and affects the quality of water available to local communities and other resource users.3737Akinnawo, S. O. (2023). Eutrophication: Causes, consequences, physical, chemical and biological techniques for mitigation strategies. Environmental Challenges, 12, 100733.

Nutrient releases from aquaculture in the form of faeces and uneaten feed can lead to eutrophication and negatively impact oxygen availability and other water quality parameters.3838Chislock, M. F., Doster, E., Zitomer, R. A., & Wilson, A. E. (2013). Eutrophication: causes, consequences, and controls in aquatic ecosystems. Nature Education Knowledge, 4(4), 10. The severity of these effects depends on factors like water depth and current velocity, location and sensitivity of the waterbody to nutrient loading.

This Criterion focuses on ASC-certified farms minimising their contribution to eutrophication by monitoring water quality, managing nutrient releases, and engaging in collaborative information sharing in at-risk waterbodies.

Intent – The aquaculture industry minimises its contribution to eutrophication and the trophic status shift of waterbodies.