The Luzon Strait (Tagalog: Kipot ng Luzon, ) is a strait in the western Pacific Ocean between Luzon in the Philippines and Taiwan, serving as a passage from the Philippine Sea to the South China Sea.
It is further divided into a number of smaller channels: the Babuyan Channel between the Luzon mainland and the Babuyan Islands; the which then separates the Babuyans from the Batanes Islands, and the Bashi Channel which separates the Batanes from Taiwan."Southeast Asia Map" . CIA World Factbook. Retrieved on June 20, 2011. It should not be confused with the Taiwan Strait, the shallower strait which passes between Taiwan and the Asian mainland.
The Luzon Strait is a major biological and ecological hotspot because its deep water channels allow the deep ocean layer flow of nutrient-rich Pacific water (called the Kuroshio Current Intrusion) into the northern part of the South China Sea, and because it is a major marine ecological corridor, serving as a migratory path and home to 18 migratory and resident seabird species and essential foraging grounds for marine mammals such as the humpback whale.
It is economically and geopolitically important as one of the world's major maritime choke points between the Americas and various important East Asian ports, and as the site of many submarine communications cables provide important data and telephony services to East and Southeast Asia.
Description The Luzon Strait is approximately wide containing a number of islands belonging to the Philippines that are grouped into two: the islands comprising the province of Batanes and the Babuyan Islands, which are part of the province of Cagayan.
The strait is divided into a number of smaller channels. The Babuyan Channel stretches from the northern shoreline of Cagayan Province on the Luzon mainland to Fuga and Camiguin de Babuyanes Islands which are the southernmost of the Babuyan Island Groups. The stretches from the main Babuyan Island to Sabtang Island in the Batanes Island Group, with the seven small, uninhabited Balintang islands in the middle. Lastly, the Bashi Channel has Mavulis Island in the Batanes Island Group as its southern boundary, and Orchid Island and Cape Eluanbi on the Taiwan mainland as its northern boundary.
Bathymetry The depth of the strait reaches the 3,500 m and 4,000 contours in north–south trenches in the middle and south-western edge. At a mean depth of 2200m, it is significantly deeper than the nearby Taiwan Strait, which has a mean depth of only 60m.
Physical oceanography Some of the largest ocean waves in the world, at times over 170 meters in height and stemming from tides and ocean currents, are found in the north of the strait. These waves or currents are underwater and rarely break the surface, thus posing no danger to shipping but are sometimes visible to satellites. The oscillation is largely prompted by a long north–south ridge which covers almost all of the strait, then amplified in the northern section by a second parallel ridge.Oskin, Becky (January 9, 2014). "Ocean's Huge Hidden Waves Explained"". LiveScience.com. Retrieved on 2014-01-13.
Kuroshio Current Intrusion
At various times of the year, the Kuroshio current - a powerful north-flowing western boundary current that transports warm equatorial water poleward and forms the western limb of the North Pacific Subtropical Gyre - leaks up to 13.7 Sverdrup... into the Luzon Strait after having flown along the eastern Philippine coast, before continuing along the Japanese coast. This affects the heat and salt budgets and circulation and eddy generation mechanisms in the South China Sea.
The deep sub-surface layers of this current bring nutrient-rich water into the northern South China Sea, enriching its dissolved organic matter stores and enhancing its ammonia oxidation. Bacteria and phytoplankton use these resources to grow and support their biogeochemical activities.
The Kuroshio current intrusion also oxidizes and increases the salinity of the sedimentary environment northwest of Luzon Island. The intrusion transports sediment high in illite and chlorite concentrations from around Taiwan southwestward into the deep sea environment. Pearl river sediments, high in concentrations of kaolinite and titanium, are also transported southwestward by the intrusion
Ecological significance
The Luzon strait and the islands covered by it includes diverse habitats including coastal and island ecosystems, pelagic and open ocean habitats, and deep sea and benthic environments.Biodiversity Management Bureau, Department of Environment and Natural Resources. (2016). Philippine Biodiversity Strategy and Action Plan (2015–2028): Bringing resilience to Filipino communities (C. Cabrido, Ed.). United Nations Development Programme; Global Environment Facility; Foundation for the Philippine Environment. https://www.cbd.int/doc/world/ph/ph-nbsap-v3-en.pdf
Biodiversity The Luzon strait serves as home to numerous migratory and resident seabird species and essential foraging grounds for marine mammals.
The Batanes Islands are specifically recognized as a key study area because of their location along migratory paths, and the Babuyan Island Group is particularly recognized as a marine Key Biodiversity Areas (mKBA) of the Philippines.
The strait contains the Philippines' only known breeding ground for Humpback whales (Megaptera novaeangliae).
Significance to global maritime traffic The Luzon Strait is the shortest possible shipping node for maritime traffic originating from the nations of Southeast Asia; combined with the collective Maritimes Southern East Asia of China, Hong Kong, Macau, and Taiwan, who are all sharing the South China Sea and it's complex economic network, with maritime traffic reaching across South and North America, wherein the Luzon Strait is the most necessary chokepoint for these two centers of gravity for economic activity.Systemic impacts of disruptions at maritime chokepoints By Jasper Verschuur and Jim HallManila-Acapulco Galleon Trade and Maritime Silk Road: Parallels and Nexus[atlas-report.com/what-is-the-luzon-strait-the-important-strategic-choleneck-in-the-south-china-sea-between-taiwan-and-the-philippines What is the Luzon Strait? The Important Strategic Choleneck in the South China Sea Between Taiwan and the Philippines By Lohanna Reis on 27 October 2025] The Luzon Strait in particular is the quickest sea lane possible, for ships travelling to and fro; Southern China and Southeast Asia, and; the Panama Canal plus South America.
Significance to global communications
Many submarine communications cables also pass through the Luzon Strait. These cables provide important data and telephony services to: mainland China, Hong Kong, Taiwan, Japan and South Korea.Greenlees, Donald and Arnold, Wayne (2006-12-29). . CNET News.com. These cables also connect to Southeast Asia: Singapore, Malaysia, Brunei, Vietnam, and Thailand. The Luzon strait also hosts cables that span Southeast Asia and the Western coasts of the Americas, mainly: the United States, and Mexico.
History Precolonial era
The Luzon Strait is believed to have been crossed by early human populations during the neolithic period. As the obvious maritime transport route between Taiwan and the Philippines, as well as the genetically and linguistically linked indigenous peoples of Taiwan and of Northeastern Luzon, the Luzon Strait looms large in theories of migration to the Philippines, sometimes eliciting controversy as in the case of the debate between the "Out of Taiwan" and "Out of Sundaland" models.
World War II
The Luzon Strait was part of the Japanese invasion route during the Second World War. On December 8, 1941 (the same day as the Japanese attack on Pearl Harbor, due to the International Date Line), forces of the Empire of Japan landed on Batanes. By December 10, they had occupied Camiguin de Babuyanes in the Babuyan Islands (not to be confused with the island-province of Camiguin off northern Mindanao) in a soon-abandoned attempt to establish a seaplane base, and on the same day landed at Aparri, Cagayan on Luzon.
Subsequently, during the Second World War, many US submarines hunted Japanese convoys passing through the strait on their way from the East Indies to Japan.
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