Fishing

Your tackle box is limited to 20 items. You'll need to use up some of those lobster traps before you can place any lures into it. Tap on any of the fishing spots where you'd place a lure. When the item menu pops up, click on the small gold circle with curved arrows on the bottom. This will take you to the second page of the menu where you'll find the traps and any nets you've made. Tap on a trap and swipe it into the fishing spot just as you'd do a lure. Now you've got an open space in your tackle box.

Just please don't tell me that you've not yet upgraded the lobster pot because, if you haven't, you won't be able to remove those lobsters from the lake, and you'll have to wait for the pot to be fixed and upgraded (it starts with room for one lobster and each upgrade adds room for one more up to a total of 6).

I usually keep 10 lures and 10 traps in my tool box. Since we need more fish than lobsters, if I choose to make a net, I trade a trap spot for it so I can keep my full supply of lures. When I set them out, I fill only 4 spaces with traps and leave the other 4 open for lure fishing. When I have a good supply of lobster, since I do need a greater supply of fish at all times, I will forgo lobster traps altogether now and then and lure fish in all 8 spots for a round or two and then return to my pattern of 4 and 4.

Hope this helps you get out of the corner you're backed into.