World Heritage Identification Number: 1362
World Heritage since: 2011
Category: Natural Heritage
WHE Type: Natural Landscapes & Geographic Features
Transboundary Heritage: No
Endangered Heritage: No
Country: 🇯🇵 Japan
Continent: Asia
UNESCO World Region: Asia and the Pacific
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Ogasawara Islands: A Biodiverse Archipelago in the Pacific Ocean
The Ogasawara Islands, officially recognized as a UNESCO World Heritage Site since 2011, constitute a unique and captivating collection of over 30 subtropical and tropical islands scattered across the Pacific Ocean. Situated approximately 1,000 kilometers south-southeast of Tokyo and 1,600 kilometers northwest of Guam, this remote Japanese archipelago offers a diverse array of landscapes and thriving ecosystems that harbor a remarkable assortment of flora and fauna.
More to come…UNESCO Description of the World Heritage Site
The property numbers more than 30 islands clustered in three groups and covers surface area of 7,939 hectares. The islands offer a variety of landscapes and are home to a wealth of fauna, including the Bonin Flying Fox, a critically endangered bat, and 195 endangered bird species. Four-hundred and forty-one native plant taxa have been documented on the islands whose waters support numerous species of fish, cetaceans and corals. Ogasawara Islands' ecosystems reflect a range of evolutionary processes illustrated through its assemblage of plant species from both southeast and northwest Asia, alongside many endemic species.
UNESCO Justification of the World Heritage Site
Criterion (ix): The property's ecosystems reflect a range of evolutionary processes illustrated through its rich assemblage of plant species from both a Southeast Asian and a Northeast Asian origin. There is also a very high percentage of endemic species in selected taxonomic groups, resulting from these evolutionary processes. Within the flora it is an important centre for active, ongoing speciation. The Ogasawara Islands provide valuable evidence of evolutionary processes through their significant on-going ecological processes of adaptive radiation in the evolution of the land snail fauna as well as in their endemic plant species. The examples of fine-scale adaptive radiation between and sometimes within the different islands of the archipelago are central to the study and understanding of speciation and ecological diversification. This is further enhanced by the relatively low extinction rates in taxa such as the land snails. It is the combination of both the concentration of endemism and extent of adaptive radiation evident in the Ogasawara Islands which sets the property apart from other places illustrating evolutionary processes. When taking into account their small area, the Ogasawara Islands show exceptionally high levels of endemism in land snails and vascular plants.
Encyclopedia Record: Bonin Islands
The Bonin Islands, also known as the Ogasawara Islands , is a Japanese archipelago of over 30 subtropical and tropical islands located around 1,000 kilometers (620 mi) SSE of Tokyo and 1,600 kilometers (1,000 mi) northwest of Guam. The group as a whole has a total area of 84 square kilometers (32 sq mi) but only two of the islands are permanently inhabited, Chichijima and Hahajima. Together, their population was 2,560 as of 2021. Administratively, Tokyo's Ogasawara Subprefecture also includes the settlements on the Volcano Islands and the Self-Defense Force post on Iwo Jima. The seat of government is Chichijima.Additional Site Details
Area: 7,939 hectares
Number of Components: 19
Coordinates: 27.7183333333 , 142.0997222222
IUCN World Heritage Outlook
The 2025 Conservation Outlook on Ogasawara Islands reports the following assessment:
Source: International Union for Conservation of Nature (IUCN) · View assessment
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World Heritage Research
Discover scientific research and academic studies that deepen our understanding of Ogasawara Islands from its history and significance to its conservation, management, and contemporary challenges.
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New Species and New Distributional Records of the Genus Microvelia Westwood (Hemiptera: Heteroptera: Veliidae) from the Japanese Ogasawara Islands, with an Illustrated Key to Ogasawaran Species
A new species of water treaders, Microvelia (Pacificovelia) amphitrite, has been identified from the Ogasawara Islands, along with a correction to previous misidentifications involving M. douglasi and the confirmation of M. yoshitomii's presence across nine islands in the archipelago. Field surveys revealed that these species prey on arthropods, including alien species, highlighting their ecological role. The study provides an illustrated key to Ogasawaran Microveliinae species, aiding future taxonomic research.
MATSUSHIMA, R., HISASUE, Y., & WATANABE, K. (2026). New Species and New Distributional Records of the Genus Microvelia Westwood (Hemiptera: Heteroptera: Veliidae) from the Japanese Ogasawara Islands, with an Illustrated Key to Ogasawaran Species. Journal of the International Heteropterists’ Society, 3(1), 85–103. https://doi.org/10.11646/jihs.3.1.2
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Ctenochaetus striatus
Ctenochaetus striatus, commonly known as the striated surgeonfish, exhibits a broad distribution across the Red Sea and Indo-West Pacific regions, including notable occurrences in the Ogasawara Islands. This species has been documented in various locations such as the Gulf of Suez, Gulf of Aqaba, and the main basin of the Red Sea, with historical records spanning from 1825 to recent observations. The study highlights its presence in diverse marine environments, ranging from East Africa to central Japan, underscoring its adaptability and ecological significance. Despite its widespread distribution, Ctenochaetus striatus is currently classified as Least Concern by the IUCN (2012), indicating a stable population status without immediate conservation concerns.
Golani, D., & Fricke, R. (2026). Ctenochaetus striatus. Zenodo. https://doi.org/10.5281/ZENODO.19176773
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Coinvasional disruptions to island pollinator networks
Biological invasions can disrupt pollinator networks, but most studies focus on single invasive species. This study reveals that multiple co-occurring invaders—green anoles (a predator), western honey bees (a floral competitor), and invasive plants—synergistically reduce pollinator diversity and plant resource use in the Ogasawara Islands. Using structural equation models, researchers found that anole abundance had the strongest negative impact on pollinators, triggering cascading effects, while honey bee abundance directly reduced plant specialization. The degree of invasion influenced whether honey bees compensated for lost functions or exacerbated invasional meltdown. These findings underscore the need to evaluate invasions in a multistressor context to develop effective conservation strategies for vulnerable island ecosystems.
Quitián, M., Planas‐Sitjà, I., Morooka, M., Traveset, A., Tierney, S. M., & Cronin, A. L. (2026). Coinvasional disruptions to island pollinator networks. Conservation Biology, 40(5). Portico. https://doi.org/10.1111/cobi.70304
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Forecasting the Risk of Reinvasion by the Giant African Snail in Ogasawara, Japan
A study on the Ogasawara Islands, Japan, identifies high-risk areas for potential reinvasion by the giant African snail (Achatina fulica), despite its declining population since the 1990s. Researchers developed species distribution models (SDMs) using MaxEnt, leveraging data from Chichijima and Hahajima in Ogasawara, as well as Hualien County, Taiwan—both sites with high-density populations. The model trained on Hahajima data proved most accurate for predicting conditions on Chichijima due to similar environmental factors, pinpointing previously unsurveyed but vulnerable zones. This approach demonstrates the effectiveness of transferring SDMs across regions to improve risk assessment in data-limited scenarios, offering a proactive strategy for invasive species management and early intervention.
Matsumoto, M., & Osawa, T. (2026). Forecasting the Risk of Reinvasion by the Giant African Snail in Ogasawara, Japan. Biotropica, 58(3). Portico. https://doi.org/10.1111/btp.70207
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A ‘fish finder’ for birds? Route-dependent foraging behavior of the brown booby ( Sula leucogaster ) following a passenger ferry in the Ogasawara Islands, Japan
Brown boobies (Sula leucogaster) exhibit route-dependent foraging behavior around passenger ferries, suggesting that these vessels may act as 'fish finders' by disturbing surface-associated prey like flying fish. Research conducted in the Ogasawara Islands, Japan—home to one of the largest breeding colonies—revealed a directional asymmetry: significantly higher numbers of boobies accompanied ferries departing from the main colony island (Hahajima) compared to southbound trips. The behavior peaked during the chick-rearing period in August, with birds following the ferry immediately upon departure but only appearing mid-route when traveling toward the colony. This pattern hints at cognitive abilities such as spatial memory and associative learning. The study highlights the potential of low-cost observational methods from public transport for behavioral research, offering a scalable approach for citizen science.
Hayashi, R. (2026). A ‘fish finder’ for birds? Route-dependent foraging behavior of the brown booby ( Sula leucogaster ) following a passenger ferry in the Ogasawara Islands, Japan. PeerJ, 14, e21093. Portico. https://doi.org/10.7717/peerj.21093
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New records of five polydesmidan millipedes (Diplopoda, Polydesmida) from the Ogasawara Islands, Japan, with notes on the postembryonic development of Prosopodesmus spp. (Haplodesmidae)
Researchers have uncovered five previously undocumented species of polydesmidan millipedes from the Ogasawara Islands, Japan, including Prosopodesmus jacobsoni, P. panporus, Cryptocorypha ornata, Dyskolonius uniramus, and Solaenaulus butteli. These findings double the known millipede diversity in the archipelago, with all species representing new records for Japan. Notably, specimens previously misidentified as Prosopodesmus sinuatus were corrected to Cryptocorypha ornata, while Solaenaulus butteli was confirmed from Chichi-jima Island. The study also examined postembryonic development in Prosopodesmus species, suggesting potential heterochronic shifts in sexual maturation. This research advances understanding of terrestrial invertebrate biodiversity in remote oceanic islands and highlights the importance of systematic surveys.
Chiyoda, S., Hisasue, Y., Yoshino, H., Kuwahara, R., & Miura, T. (2026). New records of five polydesmidan millipedes (Diplopoda, Polydesmida) from the Ogasawara Islands, Japan, with notes on the postembryonic development of Prosopodesmus spp. (Haplodesmidae). Biodiversity Data Journal, 14. https://doi.org/10.3897/bdj.14.e194219
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Species Diversity and Distribution of Non-fumigatus Aspergillus Species in Ogasawara Islands, Japan
A study on the Ogasawara Islands reveals that soil environments significantly influence the distribution of non-fumigatus Aspergillus species, including sections Flavi, Nigri, and Terrei. Researchers isolated 172 strains from 18 sites across three islands—Mukojima, Hahajima, and Chichijima—and identified seven section Flavi, five section Nigri, and three section Terrei species using calmodulin gene sequencing. Notably, Aspergillus tamarii, A. nomiae, A. niger, and A. tubingensis were dominant in forests (>60% frequency), while A. floccosus prevailed in bare land and grassland (>40%). A. pseudonomiae exhibited high occurrence across landscapes. The findings mirror previous observations for section Fumigati, suggesting environmental factors shape the dominance of these pathogenic fungi.
Tachikawa, R., Hagiuda, R., & Hirose, D. (2025). Species Diversity and Distribution of Non-fumigatus Aspergillus Species in Ogasawara Islands, Japan. Medical Mycology Journal, 66(1), 1–6. https://doi.org/10.3314/mmj.24-00017
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