The following article
details an event where a large number of a jellyfish creatures washed up on a beach in Australia. Mostly, the article is just about the alien and disturbing nature of the sight. However, the author claims:
It’s a sight we’re going to have to get used to in our warming world.
I understand jellyfish beaching is not all that rare, and seems mostly related to windstorms and tidal conditions conglomerating the creatures much in the same way weeds and garbage tend to wash up in bunches.
They give an explanation, which is that the jellyfish reproduce more in warmer waters, but I still remain skeptical there's been an increase, or that there will be an increase in the future.