sparkly fishing sign
I've noticed fishing spots with sparkly signs. I've looked all over the internet! Some say it's in relation to mermaid sims. In response to that, some have said that they only have the base game and still see these signs. What do the sparkly signs mean? I've only noticed rainbow colored sparkles. Are there different sparkles that mean different things?
The sparkling fishing signs were introduced to the base game as part of the fishing overhaul with the pre-Island Living patch in June 2019.
It means that any sim with a high level fishing skill (8 and up) has an increased chance of getting rare fish at a location with a sign that sparkles, while at the same time decreasing the chance of catching seaweed.
And there is only one type of sparkle. It's the "rainbow" one you're seeing.
However, the same visual effect is triggered when a mermaid uses the Aquatic Lure special ability on a fishing sign, which also increases the chance of getting rare fish, lowers seaweed, but also boosts a sim's fishing level (this one obviously requires having Island Living installed).
In conclusion, it's basically always preferable to fish at locations that sparkle instead of those that don't.