| Obama Bay | |
| Location: | Fukui Prefecture, Japan |
| Coordinates: | 35.5106°N 135.6893°W |
| Type: | Bay |
| Basin Countries: | Japan |
| Area: | 58.7km2 |
| Depth: | 13m (43feet) |
| Max-Depth: | 35m (115feet) |
| Volume: | 0.74km3 |
| Pushpin Map: | Japan |
| Pushpin Label Position: | left |
is a bay within Wakasa Bay in the Chūbu region of Japan, within the municipal boundaries of both Ōi and Obama. Its surface area is about 58.7km2, with a mean depth of 25m (82feet). Due to its clear waters and large beaches, it is a popular beach destination in the summer.
Obama Bay is bay within Wakasa Bay in the Chūbu region of Japan. Its mouth is bounded by Matsugazaki on the Uchitomi Peninsula on the east (part of Obama) and Ogasaki on the Ōshima Peninsula (part of Ōi) on the west. It covers an area of 58.7km2. It has a volume of 0.74km3, a maximum depth of 35m (115feet), and a mean depth of 13m (43feet). The bay has a ria coast, and part of the coastline borders Wakasa Wan Quasi-National Park.
The bay is a natural breakwater. Its water level is less affected by high tides, having a tidal range of less than 20cm (10inches). The bay has a single Class A river, the Kita, feeding into it. Two Class B rivers, the Tada and Minami, also empty into the bay, forming a delta within Obama Bay. Another delta is formed by the Saburi River within Ōi near Wakasa-Hongō Station. Its watershed has an annual precipitation of over 2000mm, and discharge into the bay is highest during March-April and June-September. Its alluvial plain has over 100 active artesian wells.
Its waters are very clear and it has many beaches, so it is a popular summertime beach destination.
Obama Bay is found within Fukui Prefecture, with the following municipalities bordering the bay:
The following rivers discharge into Obama Bay:
Major islands found in Obama bay include Ao Island and Kanja Island.
Flora include various phytoplankton and benthic microalgae, including the following:
Obama Bay contains a wide diversity of fauna: