The player pie_man has been very helpful indeed and sent me all his available data on Marshville, which means I can now finally add that area to the Area Fishing Guide. Go check it out =)
It's fun to discover new types of fish that are available as the season changes. Right now in Tombani Town for example, you can catch the Largemouth Yellowfish.
Also some minor updates have been made to the Fish Market Guide.
Have fun! =)