Abstract—Fish-feed is a major cost component of operating expenses for any aquaculture farm. Due to soaring prices of fish-feed ingredients, the need for better feeding schedule management has become imperative. On such factor that influences the utilization rate of fish-feed are sea currents. Up to now, practical monitoring of fish- feed loss due to sea currents is not exercised. This paper gives a description of an economic methodology that aims at quantifying the amount of fish-feed lost due to sea currents and draws on data from a Mediterranean aquaculture farm to formulate the associated model. Keywords—Aquaculture, economic model, fish-feed loss, sea currents. I. INTRODUCTION ISH-feed is perhaps the most crucial cost factor for any aquaculture company’s operating expenses. It is generally accepted that fish-feed cost represents from 50 to 70% of total aquaculture production costs [1],[2]. As the ingredients of fish-feed soar caused by the rise of their respective commodities’ value, (typical ingredients are soybean, corn, fishmeal, fish oil, rice and wheat) [1] so does its impact on the operating costs. Apart from the aspect of economic loss, if large quantities of uneaten fish-feed sink to the bottom beneath the cages they may also have an unfavorable impact on the marine environment. Water quality will be affected, fish stock will be threatened and deleterious impacts will be created on the surrounding marine environment. This is because oxygen depletions may occur due to decomposition of accumulated waste materials in addition to fish feces. As a result, aquaculture companies try to balance their feeding strategies to ensure maximum utilization of fish-feed, thus minimizing loss. Feeding too little results in low fish-feed cost but also less growth [3]. Conversely, feeding too much in order to achieve greater growth leads to feed wastage, a pure economic loss, and of course greater waste output [3],[4]. Maximizing fish-feed utilization comes as result of an iterative procedure with the use of formal and empirical ways. Formal ways come in the form of theoretical biological models [4], economical models or of feeding charts provided by feed manufacturers or found in various publications [3]. Empirical ways have the form of empirical biological models based on specific case studies (farm, species reared, environmental parameters etc.) see [5], and as [3] states, Vassiliou Vassos, Charalambides Marios and Menicou Michalis are with Frederick Research Centre, 1303 Nicosia, Cyprus (e-mail: eng.vv@fit.ac.cy; bus.cm@fit.ac.cy; eng.mm@fit.ac.cy). common sense, the so-called human heuristic. Yet the simplest factor that a producer can monitor in order to minimize the fish-feed loss, is the prevailing environmental conditions at the farm site at the time of feeding. While prevailing environmental conditions in respect to aquaculture enclose a number of parameters such as wind, waves, currents, water temperature, oxygen levels etc., a producer can narrow those down to just about two groups, (a) winds and waves and (b) sea currents. Even though the former is easy to understand how it affects the fish-feed loss, the latter is not as obvious. It is possible for strong currents to exist without the coexistence of high waves and/or strong winds. Currents, in terms of depth of occurrence, speed and direction, even though are necessary for adequate water exchange and waste dispersion, need to be within defined values. Strong currents will apparently drift the feed pellets away from the cage before the fish have time to eat. This eliminates the adequate opportunity, in terms of time, for fish to consume the determined ration and achieve their growth potential [3]. Consequently, this paper presents a straightforward methodology for quantifying how much fish-feed is lost due to sea currents. All associated input parameters are explained and their nature is described. Note that the terms aquaculture sites and fish farms are going to be used interchangeably in this paper. II. LITERATURE REVIEW In aquaculture industry, the amount of fish-feed lost is addressed as part of pollutants dispersion models generally develop to monitor organic waste and their impact on the marine environment, which include fish-feces [6], and antibiotics [7]. One such commercial model is called MOM which stands for Modelling - Ongrowing fish farms-Monitoring and it is used to adjust the local environmental impact of marine fish farms [8]. The MOM model is composed out of five sub- models, the most important of which is the dispersion sub- model. This simulates dispersion and sedimentation rates of excess feed and fecal pellets [8]. In particular, as [8] states, from the current variability, and the estimated sinking time for the organic waste, the model calculates how waste from a single net cage spreads over the bottom. Another well-known model is the DEPOMOD. This commercial model was developed in Scotland to predict organic deposition under finfish aquaculture sites [9]. It is a computer particle tracking model and it is used for assessing Minimizing Fish-feed Loss due to Sea Currents: An Economic Methodology F V. Vassiliou, M. Charalambides, and M. Menicou World Academy of Science, Engineering and Technology International Journal of Animal and Veterinary Sciences Vol:7, No:3, 2013 170 International Scholarly and Scientific Research & Innovation 7(3) 2013 scholar.waset.org/1307-6892/11220 International Science Index, Animal and Veterinary Sciences Vol:7, No:3, 2013 waset.org/Publication/11220