My first ever (somewhat presentable) overunder photo, portrait format taken with a rental camera with underwater housing., I tried some landscape format versions but they all failed. Jellyfish Lake, Republic of Palau, Micronesia.
The jellyfish evolved in the lake without any predators, and over time grew vegetarian and lost their ability to sting. Their red color is a result of an algae diet. The water in the lake is salty and connected underground to the ocean but not even the tiniest jellyfish can get in or out.