Omura Bay - Omurawan

A bay in the center of mainland Nagasaki Prefecture. At first glance it appears to be an inland lake, but in fact to the north of the bay are Haiki Seto and Harioseto (Inoura Seto), making it a large inlet that connects to the open sea. It is about 26 kilometers north to south and 11 kilometers east to west. It is also known as Kotonoumi or Kinkai. The undersea topography within the bay is shallow on the east side, with a water depth of around 10 meters in the center of the bay and 25 meters on the west side, with a water depth of around 30 meters in Harioseto, which connects to the open sea, and just around 3 meters in Haiki Seto. The bay is dotted with islands such as Mishima, Usushima, Shikanoshima, Yokoshima, and Takashima, and around Mishima, close to the city of Omura on the east side, the water is only about 5 metres deep, making it easy to build the Airport Bridge to Nagasaki Airport. There is a record in the Hizen no Kuni Fudoki of white pearls being found in the bay, and pearl production has been carried out since ancient times. Pearl farming has also been practiced since the Meiji period, and the National Pearl Research Institute was located at Kushimazaki on the east coast. Kashima in the southern part of the bay is the birthplace of Ikiriki mandarin oranges. Fishing within the bay is mainly done by line fishing, small-scale bottom trawling, and small-scale fixed net fishing.

[Yasuyoshi Ishii]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

長崎県本土の中央部にある湾。一見すると内陸湖の観を呈するが、実は湾の北方に、早岐瀬戸(はいきせと)と針尾瀬戸(はりおせと)（伊ノ浦瀬戸）があって外海に通ずる一大湾入である。南北約26キロメートル、東西約11キロメートル。琴湖(ことのうみ)または琴海(きんかい)の別名がある。湾内の海底地形は、東側が浅く、湾の中央部で10メートル内外を示し、西側では25メートルの水深を示し、外海に通ずる針尾瀬戸では30メートル内外、早岐瀬戸ではわずかに3メートル内外である。湾内には箕島(みしま)、臼(うす)島、鹿(しか)ノ島、横島、鷹(たか)島などの島嶼(とうしょ)が散在し、東側の大村市街地に近い箕島付近は、水深5メートル内外で、長崎空港への空港大橋もその架橋が容易であった。湾内では『肥前国風土記(ひぜんのくにふどき)』に白珠(しらたま)が採取された記録があり、真珠生産は古くから行われ、明治以後は真珠養殖も行われ、東岸の玖島(くしま)崎には国立真珠研究所があった。湾の南部の鹿島は伊木力(いきりき)ミカン発祥地。湾内漁業は一本釣り、小型底引、小型定置網漁を主としている。

［石井泰義］

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