This is an underwater zone. It features all the restrictions and special mechanics of underwater adventuring. Amongst other things, this means this zone has a -50% penalty to meat drops and item drops.
Banishing all three of the shrimp, wild girl, and broctopus will result in tumbleweeds appearing (and any unbanished quest monsters). Adding extra copies of the target quest monster, such as with Transcendent Olfaction, will result in an increased encounter rate.