Editing Geography of Japan (section)

===Lakes and coasts===
[[File:20091015琵琶湖.jpg|thumb|Aerial view of [[Lake Biwa]]]]
{{main|List of lakes of Japan}}

The largest freshwater lake is [[Lake Biwa]] ({{convert|670.3|km2|sqmi|abbr=on}}), northeast of Kyoto in [[Shiga Prefecture]].<ref name=Tabata2016>{{Cite journal |doi=10.1002/ece3.2070 |title=Phylogeny and historical demography of endemic fishes in Lake Biwa: The ancient lake as a promoter of evolution and diversification of freshwater fishes in western Japan |year=2016 |last1=Tabata |first1=Ryoichi |last2=Kakioka |first2=Ryo |last3=Tominaga |first3=Koji |last4=Komiya |first4=Takefumi |last5=Watanabe |first5=Katsutoshi |journal=Ecology and Evolution |volume=6 |issue=8 |pages=2601–2623 |pmid=27066244 |pmc=4798153|bibcode=2016EcoEv...6.2601T }}</ref> Lake Biwa is an [[ancient lake]] and is estimated to be the 13th oldest lake in the world, dating to at least 4 million years ago.<ref name="marine-rutgers">{{cite web |title=Ancient lakes of the world |url=https://marine.rutgers.edu/~cfree/ancient-lakes-of-the-world/|archive-url=https://web.archive.org/web/20200209063201/https://marine.rutgers.edu/~cfree/ancient-lakes-of-the-world/|archive-date=February 9, 2020|access-date=20 January 2020 |publisher=Christopher M. Free |format=website}}</ref><ref name=Tabata2016/> It has consistently carried water for millions of years. Lake Biwa was created by plate tectonics in an active rift zone. This created a very deep lake with a maximum depth of {{convert|104|m|feet|abbr=on}}. Thus, it is not naturally filled with sediment. Over the course of millions of years, a diverse ecosystem evolved in the lake. It has more than 1,000 species and subspecies. There are 46 native fish species and subspecies,<ref name=fish>Kawanabe, H.; Nishino, M.; and Maehata, M., editors (2012). ''Lake Biwa: Interactions between Nature and People.'' pp 119-120. {{ISBN|978-94-007-1783-1}}</ref> including 11 species and 5 subspecies that are endemic or near-endemic.<ref name=Tabata2016/> Approximately 5,000 [[Anatidae|water birds]] visit the lake each year.

The following are the 10 largest lakes of Japan.<ref name="GSI-20172">[[国土地理院]] 平成29年全国都道府県市区町村別面積調 [http://www.gsi.go.jp/KOKUJYOHO/MENCHO/201710/f1_kosho.pdf 付1 湖沼面積（平成29年10月1日版）] {{Webarchive|url=https://web.archive.org/web/20180210003158/http://www.gsi.go.jp/KOKUJYOHO/MENCHO/201710/f1_kosho.pdf|date=2018-02-10}} 2018年2月10日閲覧。</ref>

{| class="wikitable sortable"
|-
! class="unsortable"|Rank
! Name
! Region
! Prefecture
! class="unsortable"|Municipalities
!Type
! class="unsortable"|Water [[salinity]]
! Area (km<sup>2</sup>)
! Max Depth (m)
! Altitude (m)
! Volume (km<sup>3</sup>)
|-
| 1 || [[Lake Biwa|Biwa]] || [[Kansai region|Kansai]] || [[Shiga Prefecture|Shiga]] || [[Ōtsu, Shiga|Ōtsu]], [[Kusatsu, Shiga|Kusatsu]], [[Higashiōmi, Shiga|Higashi-Ōmi]], [[Hikone, Shiga|Hikone]]<br />[[Nagahama, Shiga|Nagahama]], [[Moriyama, Shiga|Moriyama]], [[Ōmihachiman, Shiga|Ōmi-Hachiman]]<br />[[Takashima, Shiga|Takashima]], [[Yasu, Shiga|Yasu]], [[Maibara, Shiga|Maibara]]
|[[Ancient lake]], [[Lake|tectonic]], [[freshwater]]|| Fresh || 670.3 || 103.8 || 85|| 27.5
|-
| 2 || [[Lake Kasumigaura|Kasumigaura]] || [[Kantō region|Kantō]] || [[Ibaraki Prefecture|Ibaraki]] || [[Tsuchiura, Ibaraki|Tsuchiura]], [[Ishioka, Ibaraki|Ishioka]], [[Omitama, Ibaraki|Omitama]], [[Inashiki, Ibaraki|Inashiki]]<br />[[Ami, Ibaraki|Ami]], [[Kasumigaura, Ibaraki|Kasumigaura]], [[Namegata, Ibaraki|Namegata]], [[Itako, Ibaraki|Itako]], [[Miho, Ibaraki|Miho]]
|Warm [[monomictic lake]]|| Fresh || 167.6 || 7.10 || 0 || 0.85
|-
| 3 || [[Lake Saroma|Saroma]] || [[Hokkaido]] || [[Okhotsk Subprefecture|Okhotsk]] || [[Kitami]], [[Saroma, Hokkaido|Saroma]], [[Yūbetsu, Hokkaido|Yūbetsu]]
|[[Mesotrophic lake|Mesotrophic]]|| Brackish || 151.9 || 19.6 || 0 || 1.3
|-
| 4 || [[Lake Inawashiro|Inawashiro]] || [[Tōhoku region|Tōhoku]] || [[Fukushima Prefecture|Fukushima]] || [[Kōriyama, Fukushima|Kōriyama]], [[Aizuwakamatsu, Fukushima|Aizu-Wakamatsu]], [[Inawashiro, Fukushima|Inawashiro]]
|[[Tectonics|Tectonic]] lake|| Fresh || 103.3 || 94.6 || 514 || 5.40
|-
| 5 || [[Nakaumi]] || [[San'in region|San'in]] || [[Shimane Prefecture|Shimane]]<br />[[Tottori Prefecture|Tottori]] || [[Matsue, Shimane|Matsue]], [[Yonago, Tottori|Yonago]], [[Yasugi, Shimane|Yasugi]], [[Sakaiminato, Tottori|Sakaiminato]]
|[[Brackish]]|| Brackish || 86.2 || 17.1 || 0 || 0.47
|-
| 6 || [[Lake Kussharo|Kussharo]] || [[Hokkaido]] || [[Kushiro Subprefecture|Kushiro]] || [[Teshikaga, Hokkaido|Teshikaga]]
|Acidotrophic [[Volcanic crater lake|crater lake]]|| Fresh || 79.3 || 117.5 || 121 || 2.25
|-
| 7 || [[Lake Shinji|Shinji]] || [[San'in region|San'in]] || [[Shimane Prefecture|Shimane]] || [[Matsue, Shimane|Matsue]], [[Izumo, Shimane|Izumo]]
|[[Brackish water|Brackish]]|| Brackish || 79.1 || 6.0 || 0 || 0.34
|-
| 8 || [[Lake Shikotsu|Shikotsu]] || [[Hokkaido]] || [[Ishikari Subprefecture|Ishikari]] || [[Chitose, Hokkaido|Chitose]]
|[[Volcanic crater lake|Crater lake]]|| Fresh || 78.4 || 360.1 || 247 || 20.9
|-
| 9 || [[Lake Tōya|Tōya]] || [[Hokkaido]] || [[Iburi Subprefecture|Iburi]] || [[Tōyako, Hokkaido|Tōyako]], [[Sōbetsu, Hokkaido|Sōbetsu]]
|[[Oligotroph]]ic [[Volcanic crater lake|crater lake]]|| Fresh || 70.7 || 179.9 || 84 || 8.19
|-
| 10 || [[Lake Hamana|Hamana]] || [[Tōkai region|Tōkai]] || [[Shizuoka Prefecture|Shizuoka]] || [[Hamamatsu, Shizuoka|Hamamatsu]], [[Kosai, Shizuoka|Kosai]]
|[[Brackish water|Brackish]] [[lagoon]]|| Brackish || 65.0 || 13.1 || 0 || 0.35
|}

[[File:Seto_Inland_Sea.jpg|thumb|[[Seto Inland Sea]]]]
Extensive coastal shipping, especially around the Seto Inland Sea, compensates for the lack of navigable rivers.<ref name=loc/> The Pacific coastline south of Tokyo is characterized by long, narrow, gradually shallowing inlets produced by sedimentation, which has created many natural harbors.<ref name=loc/> The Pacific coastline north of Tokyo, the coast of Hokkaido, and the Sea of Japan coast are generally unindented, with few natural harbors.<ref name=loc/>

A recent global remote sensing analysis suggested that there were 765&nbsp;km<sup>2</sup> of tidal flats in Japan, making it the 35th-ranked country in terms of tidal flat extent.<ref>{{cite journal |last1=Murray |first1=N.J. |last2=Phinn |first2=S.R. |last3=DeWitt |first3=M. |last4=Ferrari |first4=R. |last5=Johnston |first5=R. |last6=Lyons |first6=M.B. |last7=Clinton |first7=N. |last8=Thau |first8=D. |last9=Fuller |first9=R.A. |title=The global distribution and trajectory of tidal flats |journal=Nature |date=2019 |volume=565 |issue=7738 |pages=222–225 |doi=10.1038/s41586-018-0805-8 |pmid=30568300 |s2cid=56481043 |url=https://www.nature.com/articles/s41586-018-0805-8 |access-date=2021-08-03 |archive-date=2021-11-24 |archive-url=https://web.archive.org/web/20211124213205/https://www.nature.com/articles/s41586-018-0805-8 |url-status=live }}</ref>