The Norwegian aquaculture is facing challenges in limited areas available for aquaculture and an efficient utilization of the carrying capacity is crucial. This necessitates combining different forms of aquaculture, and the first step in doing so is to es timate the carrying capacity for each cultivation form. This project will provide methods to determine carrying capacity for finfish farming, shellfish culture and sea ranching of lobster; all of which have huge potentials in Norwegian aquaculture. Finfis h farming may have substantial impact of the benthic fauna, but the effects on the trophic relations and the marine food web are not known. The project will provide methods for tracing fluxes and pathways of organic matter into the marine food web and sug gest threshold levels for acceptable impact. Farming and sea ranching of suspension feeding shellfish is a growing industry in Norway and a substantial increase in biomass are expected. We will develop and couple existing numerical models and thereby prov ide scientific knowledge, competence and modelling capacity that can beet the demands on assessments of carrying capacity of bivalve suspension feeders. Sea ranching is an extensive form of aquaculture and has through the Act and licenses given become a c ommencing industry. The juvenile density n the release area is a limiting factor for the carrying capacity in sea-ranching lobster, and the project will provide knowledge of the optimum stocking density.