You can prevent a bounce off the bottom by clicking to slow the fall just before the bar hits. If the green bar falls to the bottom, it will bounce (it will also bounce off the top of the range). If the progress bar hits 0, the fish gets away. Every time the fish 'escapes' the green bar, its progress bar falls (very rapidly in the early game). Your fish is caught when you’ve filled this bar right up to the top. It rises when the fish is within the green bar, and falls when the fish is outside that range. On the right of the mini-game is a vertical progress bar. So you control the green bar, by left-clicking to impart an upward acceleration to the bar - release the mouse and the bar will start to fall - half-second clicks will usually let you keep the bar hovering. The fish will fight you - it will go up and down - and you can only reel it in if you keep your green bar on it. Junk will reel in immediately, but for a fish you have to go into a mini game. Wait until something tugs on your line (you’ll see a yellow exclamation mark over your character’s head, and hear a melodic burr) and then click once to reel it in. Fish star quality depends on the distance the cast lands from walkable areas. You should find that your character casts the line into the water and waits. To catch a fish, find a source of water, walk to the edge and face the water wield your rod then left-click-and-hold with your mouse over the water. If you’re struggling with it, see the strategies below for coping with poor fishing skills. If you develop the Community Centre, you will need to develop this skill at least a bit by mid First Summer, but you can leave it alone after you have completed the Fish Tank Bundles. If you choose to side with Joja Corporation, you can still develop your farm without ever going fishing.

Fishing is the one skill with least impact on your game.

Stardew valley fishing guide