Increasing interest exists in understanding how climate variabilities will influence natural resources, consequently impacting fishing behaviour and fleet economics. The question how distribution changes of highly migratory species, induced by ocean warming, will affect key fishing opportunities will be addresses by applying an integrative optimization and simulation bio-economic model, FishRent. The model includes the economics of multiple fleet segments, the impact of fishing on stock development and the spatio-temporal interplay of fleet segments and fish stocks. Besides, it integrates possible effort redistribution as well as accounting for the fact that ecological and economic conditions will determine fishing effort. The model considers that management regulations itself may alter profitability, hence also subsequent effort decisions by fleet segments, in turn affecting the commercial fish stock. By applying this model to the Northeast Atlantic mackerel and North Sea herring fishery, current management plans and two alternative scenarios will be tested: The “World Market”-Scenario will focus on a rather unsustainable exploitation, whereas the “Global Sustainability”-Scenario places emphasis on sustainable fisheries by integrating management measures such as MPA’s. All scenarios will be combined with both significantly increasing (RCP 8.5) and low-level (RCP 4.5) CO2-emissions, simultaneously considering the increasing north-westerly spawning and feeding distribution of Northeast Atlantic mackerel and poor post yolk-sac larvae survival of North Sea herring due to potential mismatches of spawning time and plankton blooms. As the fleet economics of both European and Non-European countries are affected, IIFET represents a perfect opportunity to introduce and discuss further aspects of this case study.