Despite being called a bay, it's actual position is wedged between the Dry Reef and Moss Blanket. It is to the west of the map, and starts where those islands to the Moss Blanket are. This is basically a rendition of the Slime Sea, but as an entire biome. Some of the islands have to be moved so that they fit on the map.
The original areas are left in, they are just parts of the areas. Every biome becomes the size of the entire range.