Yes, jellyfish population is increasing and it's literally swarming the waters of Japan according to Yahoo News and likely, this is not an isolated case. It is also disturbing that the ones found lurking there are the big and venomous ones called Nomura's jellyfish.

I wouldn't worry much about jellyfish stings if they are the ones we found in Siargao; their jellyfish did not sting!

I have been more scared of jellyfish sting when I encountered some while on vacation with friendsin Palawan. We were swimming near the beach and suddenly a slight stingy almost electric feeling came to my leg. A friend felt it too so we immediately went out of the water feeling scared of something unknown. A few days after, we went swimming again on a different location and suddenly, a friend screamed in pain and hurriedly  went out of the water. We were worried and it was a good thing that there were experienced swimmers in that area and we were told to find some vinegar to pour on our friend's legs; that was when we saw this transparent jelly-like tentacles wrapped around her legs!

The tentacles left some red welts on her legs and she said she felt the sting like it was a painful electric current going through her legs up to her body. Her doctor told her she was lucky because some people died of heart attack because of these nasty jellyfish stings.

Our guardian angels were protecting all of us closely at that time. Thank goodness for that.