Obama Bay
Bay in Fukui Prefecture, Japan
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Obama Bay (小浜湾, Obama-wan) 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 58.7 square kilometres (22.7 mi2), with a mean depth of 25 metres (82 ft). Due to its clear waters and large beaches, it is a popular beach destination in the summer.
| Obama Bay | |
|---|---|
| 小浜湾 (Japanese) | |
Aoshima (island) in Obama Bay. | |
  Obama Bay | |
| Location | Fukui Prefecture, Japan |
| Coordinates | 35°30′38.16″N 135°41′21.52″E |
| Type | Bay |
| Part of | |
| River sources |
|
| Basin countries | Japan |
| Surface area | 58.7 km2 (22.7 mi2) |
| Average depth | 13 m (43 ft) |
| Max. depth | 35 m (115 ft) |
| Water volume | 0.74 cubic kilometres (0.18 mi3) |
| Settlements | |
Geography
Obama Bay is bay within Wakasa Bay in the Chūbu region of Japan.[1][2] 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.[3][4][5] It covers an area of 58.7 square kilometres (22.7 mi2).[4][6] It has a volume of 0.74 cubic kilometres (0.18 mi3), a maximum depth of 35 metres (115 ft), and a mean depth of 13 metres (43 ft).[6] 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 20 centimetres (7.9 in).[1][6] The bay has a single Class A river, the Kita, feeding into it.[1][2][3][5] Two Class B rivers, the Tada and Minami, also empty into the bay, forming a delta within Obama Bay.[1][2][3][5] Another delta is formed by the Saburi River within Ōi near Wakasa-Hongō Station. Its watershed has an annual precipitation of over 2,000 millimetres (79 in), and discharge into the bay is highest during March-April and June-September.[1][6] Its alluvial plain has over 100 active artesian wells.[1][6]
Its waters are very clear and it has many beaches, so it is a popular summertime beach destination.[4]
Border communities
Obama Bay is found within Fukui Prefecture, with the following municipalities bordering the bay:
Major rivers
The following rivers discharge into Obama Bay:
- Kita River[1][2]
- Minami River[1][2]
- Saburi River
- Tada River
Major islands
Major islands found in Obama Bay include Ao Island and Kanja Island.
Flora and fauna
Flora include various phytoplankton and benthic microalgae,[1][6] including the following:
- Bacteriastrum hyalinum[3]
- Ceratocorys horrida[3]
- Chaetoceros:
- Protoperidinium:
- Pseudo-nitzschia seriata[3]
- Pyrocystis pseudonoctiluca (Pyrocystis noctiluca)[3]
- Sargassum:
- S. confusum[7]
- S. coreanum[7]
- S. gigantifolium[8]
- S. hemiphyllum[7]
- S. horneri[7][8]
- S. macrocarpum[7]
- S. micracanthum[7][8]
- S. miyabei[7][8]
- S. muticum[7]
- S. patens[7][8]
- S. piluliferum[7][8]
- S. ringgoldianum[7][8]
- S. sagamianum[8]
- S. serratifolium[7][8]
- S. siliquastrum[7]
- S. thunbergii[7][8]
- S. tortile[8]
- Thalassionema nitzschioides[3]
- Tripos:
Obama Bay contains a wide diversity of fauna:
- Acartia:
- Ascidiacea[9]
- Apoprionospio dayi (Spionidae)[9]
- Asian date mussel (musculus senhousia)[10]
- Black seabream[6]
- Corycaeus (Corycaeidae)[3]
- Euterpina acutifrons (Euterpe acutifrons)[3]
- Gammarids (various)[1]
- Ampelisca brevicornis (Ampeliscidae)[5]
- Glycera chirori[9]
- Hermit crab[6]
- Holothuria[9]
- Japanese sea bass[6]
- Linopherus (Pseudeurythoe)[9]
- Lumbrineris longifolia[9]
- Magelona japonica[9]
- Mediomastus[9]
- Microsetella:
- Nannocalanus minor (Calanus minor)[3]
- Nephtys paradoxa[9]
- Notomastus[9]
- Oithona:
- Oncaea:
- O. media[3]
- O. venusta[3]
- Paracalanus parvus[3]
- Paraprionospio[9]
- Polydora flava orientalis[5][10]
- Prionospio ehlersi[9]
- Spiophanes kroyeri (Spionidae)[9]
- Tambalagamia fauveli (Nereididae)[9]
- Terebellides stroemii[10]
- Theora lubrica[5][10]
- Timoclea micra (Veremolpa micra, part of Veneridae)[5]
- Turban snail[1]
