Nature-based aquaculture (NbA) is gaining attention as a pathway for aligning aquatic food production with climate mitigation, climate adaptation, biodiversity conservation, and human wellbeing, yet its evidence base remains fragmented across species groups, production systems, and outcome domains. Preliminary evidence mapping shows that NbA research is concentrated on seaweed, bivalves, rice-aquaculture systems, crustaceans, mangrove- and wetland-associated aquaculture, and echinoderms. Reported outcomes span climate mitigation, climate adaptation, economic performance, and food and nutrition security, highlighting the potential for NbA to deliver multiple benefits while also revealing uneven evidence across outcome categories. Guided by the identified species groups and outcome domains, we refined the search strategy to systematically assess the global NbA evidence base. Searches in Web of Science and Scopus identified 23,008 records, after which a validated large language model-assisted screening process retained 7,344 records for manual review. Following manual title and abstract screening, 1,253 articles were selected for full-text screening and potential inclusion in meta-analysis. The ongoing quantitative synthesis will evaluate the performance of NbA across climate, economic, and nutrition outcomes and identify the key systems, species groups, and contextual conditions that shape synergies, trade-offs, and evidence gaps. By combining large-scale evidence mapping with meta-analysis, this study provides a systematic basis for clarifying whether and how aquaculture systems can function as a nature-based solution for climate-smart and sustainable aquatic food systems.