The recent rains will have taken care of them. Not sure if the fresh water kills them, sends them deep or on their way, but they vanish after a reasonable amount of rain, and it has rained a fair bit since last weekend.
Pica pica are the offspring of the thimble jellyfish. If exposed during one of these "blooms" you could be covered with several chicken pox like welts for up to 7 days. I've heard that a product "safesea" helps prevent the reaction.