Numerical modeling of aquaculture dissolved waste

Authors: Subhas K Venayagamoorthy Hyeyun Ku Oliver B Fringer Alice Chiu Rosamond L Naylor Jeffrey R Koseff

Publish Date: 2011/02/18

Volume: 11, Issue: 4, Pages: 329-352

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Abstract

Marine aquaculture is expanding rapidly without reliable quantification of effluents The present study focuses on understanding the transport of dissolved wastes from aquaculture pens in nearcoastal environments using the hydrodynamics code SUNTANS Stanford Unstructured Nonhydrostatic Terrainfollowing Adaptive Navier–Stokes Simulator which employs unstructured grids to compute flows in the coastal ocean at very high resolution Simulations of a pollutant concentration field in time and space as a function of the local environment bathymetry flow conditions tides and windinduced currents and the location of the pens were performed to study their effects on the evolution of the waste plume The presence of the fish farm pens cause partial blockage of the flow leading to the deceleration of the approaching flow and formation of downstream wakes Results of both the nearfield area area within 10 to 20 pen diameters of the fishpen site as well as farfield behavior of the pollutant field are presented These detailed results highlight for the first time the importance of the wake vortex dynamics on the evolution of the nearfield plume as well as the rotation of the earth on the farfield plume The results provide an understanding of the impact of aquaculture fishpens on coastal water quality

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