Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture

Abstract

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 10:385-399 (2018) - DOI: https://doi.org/10.3354/aei00276 Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture H. M. Jansen1,2,*, O. J. Broch3, R. Bannister1, P. Cranford4, A. Handå3, V. Husa1, Z. Jiang5, T. Strohmeier1, Ø. Strand1 1Institute of Marine Research, Nordnesgaten 50, 5005 Bergen, Norway 2Wageningen University and Research, Wageningen Marine Research (WMR), PO Box 77, 4400 AB Yerseke, The Netherlands 3SINTEF Ocean, Postboks 4762 Torgarden, 7465 Trondheim, Norway 4Fisheries and Oceans Canada, St. Andrews Biological Station, 125 Marine Science Dr., Saint Andrews, New Brunswick E5B 0E4, Canada 5Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, Shandong Province, PR China *Corresponding author: henrice.jansen@wur.nl ABSTRACT: The aim of this study was to define the waste plume dynamics around a salmon farm in Norway. Systematic water sampling and numerical modeling were implemented to define nutrient concentrations in the upper water column at long-term (seasonal) and short-term (between and within days) time scales. Nutrient enhancement was observed for ammonium only, while the concentrations of orthophosphate and organic wastes were never higher than the background values. The spatial magnitude of cage effluent dispersion was limited. Empirical results detected enhanced concentrations up to 100 m down-current of the farm when fish biomass was high. Model results showed that the zone of influence could occasionally reach to >1000 m. In the first year of production, when fish biomass was low, no enhancement was detected, and in April and September of the following year, average ammonium concentrations were respectively 0.2 and 0.8 µM above the background concentrations. Taking the ambient seasonal variability into account, this resulted in 1.6 times higher concentrations for both sampling months. The measured short-term temporal variability in nutrient concentrations near the cages varied up to 2 times from day to day and were 3.5 times higher in the evening compared to the morning. As seasonal investigations were performed in the morning, maximum enhancement was likely underestimated. The rapid decrease in nutrient concentrations with increasing distance from the cages suggests that the farm studied here is currently not causing significant degradation of surface water quality. Results of this study contribute to evaluating the potential for ecological mitigation of waste nutrients and provide directions for design of optimized integrated multi-trophic aquaculture facilities. KEY WORDS: Atlantic salmon · Farm scale · Nutrients · Nitrogen · Integrated multi-trophic aquaculture · IMTA · Pelagic · Environmental impact Full text in pdf format Supplementary material PreviousNextCite this article as: Jansen HM, Broch OJ, Bannister R, Cranford P and others (2018) Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture. Aquacult Environ Interact 10:385-399. https://doi.org/10.3354/aei00276 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 10. Online publication date: September 27, 2018 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2018 Inter-Research.