Fishing is one of many gameplay mechanics in Fields of Mistria, and like it or not, you'll need to fish in order to complete the Museum. There are three categories for fishing: Pond, river, and ocean. However, not every fish is available to catch year round. The fish you need for Mistria's Museum are all seasonal fish. One of these is the fall-exclusive Striped Bass. Not only does it only swim out in fall, you can only catch it in specific areas.