AEI 1:33-46 (2010)  -  DOI: https://doi.org/10.3354/aei00005

ABSTRACT: Benthic organic enrichment due to sedimentation of waste feed and fecal matter released from salmon and other marine finfish aquaculture facilities has traditionally been measured by observing changes in benthic macrofauna assemblages. Sediment oxygen consumption, dissolved nutrient fluxes and variables such as redox potentials (normalized to hydrogen potential, Eh_NHE) and dissolved ’free’ sulfides (Σ S^2–, HS^–, H₂S) (S) are also sensitive chemical indicators of benthic enrichment effects. Hypoxic or anoxic sediments are formed when high rates of organic matter (OM) sedimentation stimulate anaerobic metabolic processes such as sulfate reduction. General changes in Eh_NHE, S, OM flux and indices of macrofauna diversity in sediments as a result of increased organic enrichment around salmon aquaculture sites have been described in numerous studies. Some of the results are summarized here in empirical regressions that relate changes in sediment chemical and benthic biological variables to increased OM supply. The equations are descriptive of the data for salmon aquaculture sites where the studies were performed and further investigations are required to determine if the relationships provide general quantitative expressions for changes in sediment geochemical conditions and macrofauna community structure due to benthic organic enrichment.

KEY WORDS: Sediment organic enrichment · Redox potentials · Sulfides · Sulfate reduction · Macrofauna · Diversity

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Cite this article as: Hargrave BT (2010) Empirical relationships describing benthic impacts of salmon aquaculture. Aquacult Environ Interact 1:33-46. https://doi.org/10.3354/aei00005 Export citation Share:    Facebook - - linkedIn