Purpose: Although life cycle impact assessment methods exist for quantifying land use and its impact on the environment in the “ecosystem quality” area of protection, the impact of sea use on ecosystems has been poorly assessed so far. This paper aims to propose operational characterisation factors for all global fisheries. Methods: For a given intervention, the characterisation factor is defined as the product of the fate factor (inverse of the fish stock growth rate) and the effect factor (depleted fraction of the stock). Characterisation factors are provided for 5000 fish stocks identified by the Food and Agriculture Organization. Both the marginal and average approaches are used, and characterisation factors compatible with the ReCiPe method and the international guidelines of the Life Cycle Initiative hosted by the UN Environment Programme are proposed. Results and discussion: Characterisation factors for regional and global assessments can be employed to address the endemic nature of a species. As an illustration, four contrasting fisheries are presented and compared with land animal production systems. Impacts varied between stocks and between regional and global assessment, particularly with highly endemic species exhibiting impacts comparable to or exceeding land-based animal products. Conclusions: Although in some cases associated uncertainty is large, the proposed method allows endpoint characterisation, in line with the ReCiPe methodology and Life Cycle Initiative, contributing the assessment of fishing impacts on ecosystem quality and a more holistic representation in food impact assessment.