The dispersal of zebra mussel (Dreissena polymorpha) in freshwaters of Eastern Europe, North America and West Asia [1], became a significant problem due to severe environmental consequences such as rapid colonization on new areas in the aquatic ecosystem [2], shifts in food web and its dynamics, loss of zooplankton species [3], changes in feeding ecology and trophic conditions of endemic fish species [4, 5], with remarkable economic consequences [6]. Zebra mussel has been the most aggressive freshwater invader in wide areas of freshwater ecosystems around the world and are the only freshwater bivalve species that attach to hard substrates in high densities and have a planktonic larval stage [7]. Although veligers can settle upon a variety of surfaces, survival is influenced by surface selection, and hard structures are usually suitable surfaces for attachment. Once it has attached to a surface, both eggs and larvae of zebra mussels are

The simulation of investment strategies with different farm-scale scenarios has been evaluated for best management plan in cage farming business for the establishment of a salmon production with either full capacity – or progressive investment. Economical revenues were analyzed with business risk assessment based on operating-and fixed costs for each of the four scenarios. In the theoretical model projected for the stimulation of best management plans, structural elements for the construction of an offshore Turkish salmon farm in the Black Sea were designed and investment costs for an annual production capacity of 4,000 tons were re-scaled by 25, 50 and 75% reduction, corresponding to 3,000, 2,000 and 1,000 tons per year, respectively. Economic variables of operational costs were comparatively evaluated with the revenues and annual profit conditions by sales of harvested fish. The break-even points for all investment strategies with different farm-scale scenarios were remarkably lower (on average 302,574.7 kg/year) than the harvest yields from the farms (on average 3,702,857.1 kg/year). Based on break-even points and margin of safety (MOS over 85%), all farms gained net profits with low risks in the first year, whether the farm received full investment, or initiated business with reduced investment expenditures for a gradual and progressive expansion plan. Findings of this study exhibit useful indications for farm management in understanding conditions of a step-wise establishment of business plans for salmon farming in offshore conditions.