Comparison of Atlantic salmon net pen and recirculating aquaculture systems: economical, technological and environmental issues

Abstract

The modern aquaculture industry is a rapidly developing sector of the fisheries industry. Among the fish species reared in marine waters Atlantic salmon (Salmo salar) shares a significant part. Nowadays, the largest salmon producing countries are Norway, Chile and Scotland. The common technology used in the salmon production is a sea cage, which is presented in a form of floating plastic rings or robust metal installations fastened to a barge. In both cases, the fish is placed in the net in the open sea, and therefore, production is highly dependent on the external factors, such as environmental conditions, disease and parasites presence. Recirculating aquaculture systems (RAS) have been used to supply smolts for further production of market-size salmon at sea. Nowadays, this system is suggested to provide the whole production cycle from smolt- to market-size in the closed environment with optimal biological conditions. Nonetheless, the existing projects require higher initial investment costs than the conventional net pen farm. In the present work, comparison analysis of net pen system and RAS has been performed on the basis of the economic analysis of salmon aquaculture farm suggested by Trond Bjørndal and Frank Asche in “The Economics of Salmon Aquaculture”, 2nd edition (2011) and report “Profitability analysis of the NIRI technology for land-based salmon farming” (2008) by Krisin Roll, Arve Gravdal and Asbjørn Bergheim. The analysis includes compilation of biological and bio-economical models for the both systems. Missing or out-of-date information has been replaced by new data from additional sources such as research articles, industrial reports and expert opinions. The net present value (NPV) and internal rate of return (IRR) are the main measures that have been used in analysis. The overall conclusion from the comparison has shown that RAS is around 12 mil NOK less profitable than net pen farm in ten years time horizon, while NPV in both cases is positive. However, other findings from the research revealed an unreliability of the scaling method in respect to RAS, without detailed description of the farm production capacity and equipment. Besides, investment costs estimation is dependent on many factors that are complex and require a thorough investigation. At the same time, in spite of scientific and industrial analyses show lower impact on the environment from RAS in comparison to the net pen aquaculture system, it may be questioned in terms of RAS location and power source use.