FishRent is an integrative bio-economic optimization and simulation model that helps to understand how fisher may respond to management options and natural variations (e.g. climate change). The original FishRent model was developed in Excel by several institutes during the EU project "Study on the renumeration of spawning stock biomass". The further developed version of FishRent 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. FishRent in its current version is a dynamic feedback model and is composed of several submodules. Different from many other models, this model not only considers a possible effort redistribution, it does account for the fact that economic conditions (e.g. revenues and fishing costs) will determine fishing effort and that management regulation itself will alter profitability and hence subsequent effort decisions by fleet segments, which in turn will impact the commercial fish stock.