Lake Mainit

Lake Mainit
Lake Mainit looking south from the northern shore
Lake Mainit is located in Philippines
Lake Mainit
Lake Mainit
Location within the Philippines
LocationMindanao
Coordinates9°25′57″N 125°31′22″E / 9.43250°N 125.52278°E / 9.43250; 125.52278
TypeOligotrophic Freshwater lake
28 creeks and rivers
Calinawan River
870.72 km2 (336.19 sq mi)
Basin countriesPhilippines
Max. length29.1 km (18.1 mi)
Surface area
170.6 km2 (65.9 sq mi)
Average depth
128 m (420 ft)
Max. depth223 m (732 ft)
Water volume
18 km3 (4.3 cu mi)
Shore length1
62.1 km (38.6 mi)
Surface elevation
42 m (138 ft)
Settlements
References
1 Shore length is not a well-defined measure.

Lake Mainit is an oligotrophic lake in Mindanao. It is the fourth largest lake in the Philippines, having a surface area of 170.6 square kilometers (65.9 sq mi). The lake is also the deepest lake in the country with maximum depth reaching 223 meters (732 ft). It is located in the northeastern section of Mindanao and shared between the provinces of Surigao del Norte and Agusan del Norte.

Etymology

The name of the lake is a Visayan word mainit, which means "hot".

Geography and hydrography

Lake Mainit is an oligotrophic lake shared between the provinces of Surigao del Norte and Agusan del Norte. It has a surface area of 170.6 square kilometers (65.9 sq mi) and is 29.1 square kilometers (11.2 sq mi) long.

The lake's 62.1-kilometer (38.6 mi) shoreline covers Mainit and Alegria of Surigao del Norte; and Jabonga and Kitcharao of Agusan del Norte.

Lake Mainit is also the reservoir of the Mainit-Tubay River Basin. The Kalinawan River is the main drainageway of the river basin moving water from Lake Mainit to the Butuan Bay.

It is the deepest lake in the Philippines with the maximum depth of 223 meters (732 ft). It has a mean depth of 128 meters (420 ft).

Relation to humans

Research

Despite Lake Mainit as being considered a major lake in the Philippines, the water body is understudied and receive less scientific attention than Lake Lanao. The possible first biological work was by S.R. Manacop in 1937.

Economy

Fishing is an important economic activity by settlements around Lake Mainit. The Glossogobius giuris or the tank goby or locally known as the pijanga and the Channa striata, locally called as the haluan are the primary fish resources in Lake Mainit. However the population of the pijanga has been noted to experience a decline from 2014 to 2024. due to overfishing.

The traditional boat cast net method of laya is often used by fishers of Lake Mainit.

In 2023, a hydroelectric dam was inaugurated in Jabonga.

The Philippine–Japan Friendship Highway traverse the land adjacent on the eastern side of Lake Mainit.

References

  1. ↑ "Philippine Lakes - Lake Look to Lake Pandin". Retrieved October 17, 2008.
  2. 1 2 3 4 "Physical Features of Lake Mainit". Lake Mainit Development Alliance. February 8, 2008. Archived from the original on September 15, 2009. Retrieved May 10, 2026.
  3. ↑ "Lake Mainit". BIMP-EAGA. Archived from the original on October 30, 2008. Retrieved October 17, 2008.
  4. ↑ Gatdula, Norvida. "Feature: Advancing sustainable fisheries and ecosystem management of Lake Mainit". National Fisheries Research and Development Institute. Retrieved May 10, 2026.
  5. 1 2 Tumanda, Marcelino Jr.; Roa, Elnor; Gorospe, Jessie; Daitia, Milan; Dejarme, Sonia; Gaid, Ruth. "Limnological and Water Quality Assessment of Lake Mainit" (PDF). Mindanao State University at Naawan – via Lake Mainit Development Alliance.
  6. 1 2 3 Mangadlao, Ivy Marie (December 6, 2025). "Special Report: Decline of Lake Mainit's popular pijanga linked to overfishing, illegal harvests". Retrieved May 10, 2026.
  7. 1 2 "LiDAR Surveys and Flood Mapping of Mainit-Tubay River" (PDF). UP Training Center for Applied Geodesy and Photogrammetryaga State University. p. 1. Retrieved May 10, 2026.
  8. ↑ Lewis, William M. (January 1973). "A Limnological Survey of Lake Mainit, Philippines" (PDF). Internationale Revue der gesamten Hydrobiologie und Hydrographie. 58 (6): 801–818. Bibcode:1973IRH....58..801L. doi:10.1002/iroh.19730580603. ISSN 0020-9309. Retrieved May 10, 2026.
  9. ↑ Laudiño, Francis Alizha R.; Agtong, Rhenzlyn Joy M.; Elvira, Marlon V.; Fukuyama, Mayuko; Jumawan, Joycelyn C. (May 2023). "Accumulation of heavy metals on the muscles of striped snakehead murrel Channa striata in Lake Mainit, Philippines, and the association of its consumption on human health" (PDF). Journal of Hazardous Materials Advances. 10 100269. Bibcode:2023JHzMA..1000269L. doi:10.1016/j.hazadv.2023.100269.
  10. ↑ Paglinawan, Rosannie Joy; Paylangco, Ruby; Paylangco, Jesiel Cris; Along, Archie; Almadin, Florence Jhun (September 30, 2022). "Association of size structure, diet composition, endo-parasites of Snakehead fish (Channa striata, Bloch), in Lake Mainit, Caraga Region, Philippines". Southeastern Philippines Journal of Research and Development. 27 (2): 1–22. doi:10.53899/spjrd.v27i2.135. ISSN 2718-9201.
  11. ↑ Panganiban, Chris (August 9, 2025). "Officials warn of declining stocks of native fish in Lake Mainit". Philippine Daily Inquirer. Retrieved May 10, 2026.
  12. ↑ Mangaluz, Jean (July 12, 2023). "Energy game-changer: Bongbong Marcos unveils Agusan del Norte hydro plant". Philippine Daily Inquirer. Retrieved May 10, 2026.
  13. ↑ "24.9MW hydro plant inaugurated in Agusan Norte". MindaNews. July 12, 2023. Retrieved May 10, 2026.
  14. ↑ "Lake Mainit hydroelectric power plant: From a beautiful trauma". Philippine Information Agency. July 27, 2023. Retrieved May 10, 2026.

Further reading