Laguna de Bay (Spanish for "Lagoon/Lake of Bay"; , ), also known as Laguna Lake, is the largest lake in the Philippines. It is located southeast of Metro Manila, between the provinces of Laguna to the south and Rizal to the north. A freshwater lake, it has a surface area of 911–949 km² (352–366 sq mi), with an average depth of about and an elevation of about one meter above sea level. The lake is shaped like a crow's foot, with two peninsulas jutting out from the northern shore and filling the large volcanic Laguna Caldera. In the middle of the lake is the large island of Talim.
The lake is one of the primary sources of freshwater fish in the country. Its water drains to Manila Bay via the Pasig River. Environmental issues such as water quality problems created by population pressure and industrialization, invasive species and overfishing are of concern for the lake, hurting its economic importance to the country. As population expands in the Bay, its expected to rely more heavily on the lake for freshwater supply, thus water quality directly affects human populations.
Etymology
Laguna de Bay means "Lagoon of [the town of] Bay" for the lakeshore town of Bay (pronounced Bä'ï), the former provincial capital of Laguna province. Alternate spellings of the town's name include "Bae" or "Ba-i", and in the early colonial times, "Bayi" or "Vahi". The town's name is believed to have come from the Tagalog word for "settlement" (bahayan), and is related to the words for "house" (bahay), "shore" (baybayin), and "boundary" (baybay), among others. The introduction of the English language during the American administration of the Philippines, elicited confusion as the English word "bay", referring to another body of water, was mistakenly substituted to the town name that led to its mispronunciation. However, the word "Bay" in Laguna de Bay has always referred to the town.
The Spanish word laguna refers to not just lagoons but also for freshwater lakes, aside from lago. This would make the lake's alternate name, "Laguna Lake", tautological. However, the "Laguna" in "Laguna Lake" refers to the province of Laguna, the province at the southern shore of the lake, and not the lake itself. The province, though, was in turn named after the lake and was originally called La Laguna until the early 20th century.
In the pre-Hispanic era, the lake was known as "Puliran Kasumuran" (Laguna Copperplate Inscription, 900 AD), and later by "Pulilan" (Vocabulario de la lengua tagala, 1613. Pila, Laguna).
Currently, the lake is often incorrectly called "Laguna Bay," including in government websites, or "Laguna Lake", which is used by the Laguna Lake Development Authority.
Geography
Laguna de Bay is a large shallow freshwater body in the heart of Luzon Island with an aggregate area of about and a shoreline of . It is considered to be the third largest inland body of water in Southeast Asia after Tonle Sap in Cambodia and Lake Toba in Sumatra, Indonesia. Laguna de Bay is bordered by the province of Laguna in the east, west and southwest, the province of Rizal in the north to northeast, and Metropolitan Manila in the northwest. The lake has an average depth of and its excess water is discharged through the Pasig River.
The middle part of Laguna de Bay between Mount Sembrano and Talim Island, is the Laguna Caldera believed to have been formed by two major volcanic eruptions, around 1 million and 27,000–29,000 years ago. Remnants of its volcanic history are shown by the presence of series of maars around the area of Tadlac Lake and Mayondon hill in Los Baños, Laguna, another maar at the southern end of Talim Island, and a solfataric field in Jala Jala.
Islands
Known lake islands include Talim, the largest and most populated island on the lake; Calamba Island, which is completely occupied by the Wonder Island resort in Calamba, Laguna; Cielito Lindo, a privately owned island off the coast of mainland Cardona, Rizal; Malahi Island which used to be the site of Maligi Island military reservation, near the southern tip of Talim; the nearby islands of Bonga and Pihan, also in Cardona; and Bay Island off the coast of Bay, Laguna, which is closely associated with the precolonial crocodile-deity myths of that town.