If you see a fishing sign sparkling in The Sims 4, it means there’s a rare or valuable fish available at that fishing spot. It also means your Sim is less likely to pull up junk like seaweed instead of a fish.
The sparkle isn’t tied to your Sim’s Fishing skill. Even a Sim with Level 1 Fishing can find a sparkling fishing sign, while a Level 10 Sim can come across one too.
The sparkle depends on what’s currently available at that spot, not on your Sim’s skill level.
Your Fishing skill still matters, though. A higher skill level improves your chances of successfully catching the rare fish instead of losing the catch.
So while a sparkling sign gives you a better opportunity, having a skilled fisherman makes it much easier to take advantage of it.
If you have Island Living, there’s another reason you might see a sparkling fishing sign. A mermaid can use the Aquatic Lure ability at a fishing spot. The mermaid blows into a conch shell, and the spot then gets a temporary boost that makes rare fish more likely to appear and reduces the chance of catching seaweed.
It also gives Sims fishing there a temporary boost to their effective Fishing skill.
The sparkle isn’t a guarantee that your Sim will catch the rare fish. Your Fishing skill still makes a big difference.
A Sim with Level 10 Fishing will have a much easier time landing rare catches than a beginner, which can save you a lot of failed attempts when you’re trying to catch an Angelfish or Pufferfish.
It’s also handy when you’re trying to complete the Fish Collection without spending half your Sim’s life standing beside a pond.