Most of these shots were taken in Osaka Aquarium, Japan.

Nomura jellyfish periodically "attack", or rather infest the warm Japanese seas. Some are 1 meter wide, with the largest reportedly being up to 4 meters in length. Wikipedia article documents the invasion. In the meantime coastal communities in Japan are doing their best to promote jellyfish as a novelty food, sold dried and salted, and some even turned into cookies.