With a growing emphasis on digital analytical approaches and digitization of archival material there is an ever-increasing need for Historians to consider the best practices for utilizing these new resources and approaches. The research field of Marine Environmental History have exploited these new methods for several decades to much benefit and provides a framework of very good as well as improvable cases of application of digital approaches in historical research. This thesis revolves around a throughout update and revision of the DanDoc database including a total overhaul of the metadata embedded in the database and a full rebuild of the search functionality structure. The DanDoc database, launched as part of the NorFish project (2016-2020), contains 3499 digitalized Danish chancery letters from the period 1536 to 1654 AD curated specifically on the relation to fishing, fisheries and trade and politics related to fisheries. In this thesis, a two-pronged approach is presented where the first part focuses on the methodological work of organizing the database on a structural level, applying useful and well considered metadata to the documents and providing a useful and advanced search functionality for the users of the database. The second part consists of an analysis of the content of the database using the newly added functionalities described to explore the fisheries of the Kingdom of Denmark-Norway in the period covered by the content of the DanDoc database. The analysis shows how major changes in availability following the collapse of the Bohuslän herring fisheries in ca. 1589 may have affected the valuations and quantities observed in Danish letters of benefice in the following years. The collapse of the Bohuslän fisheries have seen much attention by scholars, but this study further qualifies the impact of this event on the regional fish supplies, using the content of the letters of benefice. Moreover, an analysis of the occurrence of documents mentioning any species of marine animals are applied to the content of the database. This analysis finds that a gradual change occurs in which species are most frequently mentioned. Finally, the study finds a growing demand for exotic marine species in the latter part of the period covered by the documents of DanDoc database, indicating a change in consumption patterns of the royalty and nobles in this period.