This paper investigates knowledge production in collaborations where the actors have different knowledge and interests. Building on boundary object theory, a conceptual framework is developed to analyse knowledge exchange in two stakeholder-led collaborations to make fishery management plans. The framework introduces boundary spaces to conceptualise the dynamic interaction between objects and activities. Within boundary spaces, actors can share, transfer and translate their knowledge, and common understanding can emerge. The collaborations analysed aimed to produce management plans for the Nephrops (Nephrops norvegicus) fishery in the North Sea and the boarfish (Capros aper) fishery in the Northeast Atlantic. Several boundary spaces were identified in each collaboration. During the production phase, the emerging management plans took on multiple representations as boundary objects that facilitated knowledge exchange. Activities were essential, as these created entry points for different actors to become part of the boundary spaces where they could contribute to knowledge production. Fishing industry representatives in the North Sea Advisory Council and the Pelagic Advisory Council played key roles in initiating and coordinating activities. The case studies demonstrate that Advisory Councils take on pro-active roles in initiatives that aim to expand the knowledge base for European fisheries management. Direct engagement was instrumental to create ownership of the problem addressed in the various collaborative settings that emerged during the management plan initiatives.