Purpose: The decline in biodiversity caused by human activities is a major global challenge. An important driver of biodiversity loss, especially in the oceans, is seafood production. However, methods for quantifying biodiversity impacts in life cycle assessment (LCA) are currently heavily focused on terrestrial systems. This study aims to identify and evaluate methods addressing aquatic biodiversity loss relevant for LCAs of seafood and to provide recommendations to research and LCA practitioners. Methods: The methodology comprised four key phases. First, environmental impacts from seafood production were identified and linked to biodiversity impacts. Second, it was assessed which impacts were addressed in existing seafood LCAs. Next, available biodiversity impact assessment methods were identified through a literature review. Finally, the identified assessment methods were evaluated and matched against the identified environmental impacts from seafood production to evaluate the efficacy of current LCA practices. Results and discussion: A total of 39 environmental impacts linked to seafood production were identified. Of these impacts, 90% were categorized as causing biodiversity loss and included effects on genetic, species, and ecosystem level. Only 20% out of the impacts associated to aquatic biodiversity loss had been included in previous seafood LCAs, indicating a narrow scope in practice, as methods were available for half of the impacts. The available methods were, however, mainly focused on impact on species level and on the drivers pollution and climate change rather than the main drivers of marine biodiversity loss: exploitation and sea-use change. Conclusions: Although many of the impacts from seafood production were related to biodiversity pressures, LCAs which are widely used to describe the environmental performance of seafood, disregard most biodiversity impacts from seafood production. The most severe limitations were the lack of methods for the pressures of exploitation and sea-use change and for effects on ecosystem and genetic biodiversity. This study provides recommendations to practitioners on how to best account for biodiversity impacts from seafood depending on the studied system, geographic area, and dataset. Future research should progress methods for impact pathways within the drivers exploitation and sea-use change, and effects on ecosystem biodiversity and genetic biodiversity.