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 sq mi), 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 / 35.5106000°N 135.6893111°E |
| Type | Bay |
| Part of | |
| River sources | |
| Basin countries | Japan |
| Surface area | 58.7 km2 (22.7 sq mi) |
| Average depth | 13 m (43 ft) |
| Max. depth | 35 m (115 ft) |
| Water volume | 0.74 cubic kilometres (0.18 cu mi) |
| Settlements | |
Geography
editObama 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 sq mi).[4][6] It has a volume of 0.74 cubic kilometres (0.18 cu mi), 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
editObama Bay is found within Fukui Prefecture, with the following municipalities bordering the bay:
Major rivers
editThe following rivers discharge into Obama Bay:
Major islands
editMajor islands found in Obama Bay include Ao Island and Kanja Island.
Flora and fauna
editFlora include various phytoplankton and benthic microalgae,[1][6] including the following:
- Bacteriastrum hyalinum[3]
- Ceratocorys horrida[3]
- Chaetoceros:
- Protoperidinium:
- P. depressum (Peridinium depressum)[3]
- P. grande (Peridinium grande)[3]
- P. oceanicum var. oblongum (Peridinium oceanicum)[3]
- 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:
- T. candelabrum (Ceratium candelabrum)[3]
- T. fusus (Ceratium fusus)[3]
- T. mollis (Ceratium molle)[3]
- T. muelleri (Ceratium tripos)[3]
- T. pennatus (Ceratium pennatum)[3]
- T. ranipes (Ceratium palmatum var. ranipes)[3]
- T. sumatranus (Ceratium smatoranum)[3]
- T. trichoceros (Ceratium trichoceros)[3]
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]
- 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:
- 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]
References
edit- ^ a b c d e f g h i j k Kobayashi, et al (2017), page 2.
- ^ a b c d e Kobayashi, et al (2017), page 3.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Yamazi, Isamu (20 November 1954). "Plankton Investigation in Inlet Waters Along the Coast of Japan - XIII. The Plankton of Obama Bay on the Japan Sea Coast" (PDF). Publications of the Seto Marine Biological Laboratory. 4 (1). Seto Marine Biological Laboratory. Archived (PDF) from the original on 17 June 2022. Retrieved 10 January 2024.
- ^ a b c d e 37. 小浜湾 [37. Obama Bay] (in Japanese). 閉鎖性海域ネット (Heisa Seikaiiki Net). 1 April 2011. Archived from the original on 3 January 2024. Retrieved 2 January 2024.
- ^ a b c d e f g Hayashi (1982), page 1765.
- ^ a b c d e f g h i Utsunomiya, Tatsuya; Hata, Masaki; Sugimoto, Ryo; Honda, Hisami; Kobayashi, Shiho; Miyata, Yoji; Yamada, Makoto; Tominaga, Osamu; Shoji, Jun; Taniguchi, Makoto (June 2017). "Higher species richness and abundance of fish and benthic invertebrates around submarine groundwater discharge in Obama Bay, Japan". Journal of Hydrology: Regional Studies. 11. Elsevier: 139–146. Bibcode:2017JHyRS..11..139U. doi:10.1016/j.ejrh.2015.11.012.
- ^ a b c d e f g h i j k l m n Umezaki, Isamu (8 March 1984). "Ecological Studies of Sargassum hemiphyllum C. AGARDH in Obama Bay, Japan Sea". Bulletin of the Japanese Society of Scientific Fisheries. 50 (10). Japanese Society of Scientific Fisheries: 1677–1683. doi:10.2331/suisan.50.1677. Archived from the original on 28 July 2018. Retrieved 10 January 2024.
- ^ a b c d e f g h i j k Umezaki, Isamu (5 December 1983). "Ecological Studies of Sargassum horneri (TURNER) C. AGARDH in Obama Bay, Japan Sea". Bulletin of the Japanese Society of Scientific Fisheries. 50 (7). Japanese Society of Scientific Fisheries: 1193–1200. doi:10.2331/suisan.50.1193. Archived from the original on 2 November 2018. Retrieved 10 January 2024.
- ^ a b c d e f g h i j k l m n Hayashi (1982), page 1768.
- ^ a b c d Hayashi (1982), page 1767.
Works cited
edit- Hayashi, Isao (18 November 1982). "Distribution of Macrobenthic Animals on the Flat Bottom in Obama Bay". Bulletin of the Japanese Society of Scientific Fisheries. 49 (12). Japanese Society of Scientific Fisheries: 1765–1775. doi:10.2331/suisan.49.1765. Archived from the original on 27 April 2019. Retrieved 10 January 2024.
- Kobayashi, Shiho; Sugimoto, Ryo; Honda, Hisami; Miyata, Yoji; Tahara, Daisuke; Tominaga, Osamu; Shoji, Jun; Yamada, Makoto; Nakada, Satoshi; Taniguchi, Makoto (24 March 2017). "High-resolution mapping and time-series measurements of 222Rn concentrations and biogeochemical properties related to submarine groundwater discharge along the coast of Obama Bay, a semi-enclosed sea in Japan" (PDF). Progress in Earth and Planetary Science. 4 (6). Japan Geoscience Union. Bibcode:2017PEPS....4....6K. doi:10.1186/s40645-017-0124-y. ISSN 2197-4284. Archived (PDF) from the original on 10 January 2024. Retrieved 10 January 2024.
External links
edit
Media related to Obama Bay at Wikimedia Commons
