The environmental effect on the seabed of an offshore marine fish farm in the tropical Pacific

• Published in: Journal of environmental management Vol. 300; p. 113712
• Main Authors: Sanz-Lazaro, Carlos, Casado-Coy, Nuria, Calderero, Edwin Moncayo, Villamar, Ulises Avendaño
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.12.2021
• Subjects: Aquaculture environment interactions; Environmental impact; Macrofauna; Offshore aquaculture; Organic enrichment; Pacific ocean; Aquaculture environment interactions; Organic enrichment; Macrofauna; Offshore aquaculture; Environmental impact; Pacific ocean
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2021.113712

Marine aquaculture is expanding offshore, where the environmental interactions are not yet fully understood. We performed a benthic environmental assessment of an offshore fish farm on unconsolidated sediment. The physicochemical variables showed marked changes just under the fish farm, although the structure of the community and its bioturbation potential were not influenced. Under no or minimum influence from the fish farm, the physicochemical variables, including acid-volatile sulphides and redox, were notably different to those found in unaffected coastal areas. For this reason, classifications of the environmental status based on physicochemical variables should be adapted to offshore areas. Despite the low degree of impact detected, the organic matter carrying capacity should be carefully determined to avoid environmental drawbacks in terms of fine-grained offshore sediments. Offshore aquaculture could have a lower environmental impact than other types of aquaculture located closer to the coast, but further research is needed to obtain conclusive results. [Display omitted] •Physico-chemical parameters were only affected below the fish farm.•Macrofauna community was not influenced by the fish farm.•Environmental status classifications should be adapted to offshore areas.•Offshore fish farming can have a lower impact than other types of aquaculture.