Greetings, you are definitely onto something here!
I know very little about fishing, but I love the concept behind your game. The fact that it's turn-based is a very appropriate choice for a laid-back relaxing experience. The fish finder 3000 is a cool touch and the color palette works well.
There are several things that I wish were different:
1.Make it playable entirely with the mouse (including the boat movement)
2.The UI buttons on the bottom right are not very good, please do some research on mystery meat navigation and how to avoid it
3. Show the minimap above the fish finder, would be much more useful there
4.The graphics need work, I like the low-res style, but some of the sprites just look primitive
5. I want to see detailed pictures (preferably procedural) of the catch, including stats! That's my reward for playing, right?
Overall it's a great concept, I think the primary thing you should focus on is guiding players like me who know nothing about fishing. This sort of game is the perfect opportunity to teach people and share your elite fishing knowledge. For example, I have no idea what the difference is between the rods. I know there is a manual but this is a turn-based game, so you can just show me the tips in-game.
Great job, this is one of the most original and complete prototypes that I've played on here.