The Senkaku Islands are isolated islands floating in the East China Sea and are inhabited by organisms that thrive in the subtropical oceanic climate and are biologically invaluable to the geological history of the islands. Many of the flora and fauna observed in the academic survey conducted in 1979 have been designated as endangered or near threatened species.
Grows on terrain such as the cloud belt and rocky areasof the windswept mountain peaks of Uotsuri Island. A woody shrub that grows to about 50 cm tall. The flowers, measuring 3 – 4 cm in diameter, grow on the tips of small branches. An endemic species of Uotsuri Island.
Photography: Yoshima Niiro
A shrub that sometimes grows as a creeper on windy terrain on the mountain peaks of Uotsuri Island. The flower is small and light purple in color, and grows densely in the tree canopy. Some flowers have been brought back from the islands and cultivated for ornamental uses.
Photography: Kazuharu Shinjo
Photography: Yoshima Niiro
A perennial herb that grows on the coasts and elevated coral reefs of Uotsuri Island. Exists in extremely small populations in its habitats, and is considered to be an endemic species of Uotsuri Island.
Photography: Yoshima Niiro
The population of albatross (Diomedea albutrus) has been on the rise since 1971, when their inhabitation of Minamikojima Island was confirmed by a research group from the University of the Ryukyus for the first time in 71 years. In recent years, surveys conducted mainly by Hiroshi Hasegawa have confirmed the continued propagation of albatross on Minamikojima and Kitakojima Islands. Even from a global perspective, the Senkaku Islands, along with Torishima Island, Izu, are invaluable breeding grounds for albatross and therefore should be protected.
Adult bird and chick (Minamikojima Island)Photography: Kunio Mizushima
Adult birds (Minamikojima Island)Photography: Kunio Mizushima
Chick (Kitakojima Island)Photography: Kunio Mizushima
The brown booby (Sula leucogaster plotus) on Minamikojima Island uses the entire slope of the rocky mountain that forms the main part of the island as its nesting site. Adults and their chicks would be found up on the main slope, and the adults would exhibit threatening behavior to anyone approaching their nests. In such cases, they may spit out fish, for example flying fish, and then take off into the air. However, as they are unable to fly up into the air immediately, they seem to almost stumble along the slope before gliding and flying away.
Brown booby brooding over its eggs (Minamikojima Island)Photography: Yoshima Niiro
Brown booby chicks (Minamikojima Island)Photography: Yoshima Niiro
Nesting site (Minamikojima Island)Photography: Yoshima Niiro
A survey conducted in 1955 found that one side of the slopes was used by sooty terns (Sterna fuscata nubilosa) as their nesting site. The area was so crowded then that there was hardly any space for the surveyors to stand in. However, according to a survey conducted in 1979, the number of sooty terns has declined drastically because of overhunting and other factors, while the grassland area has increased.
Nesting site (Kitakojima Island)Photography: Yoshima Niiro
Sooty terns nesting around the nesting site of the greater crested tern (Kitakojima Island)On Kitakojima Island, the entire grassland area used to be covered by sooty terns and greater crested terns (Thalasseus bergii cristatus) using the land as their nesting sites. The grass at the heart of the colonyhad withered and turned brown from being trod on by the birds as well as from the excrement they left. After they flew away, it was observed that countless eggs were left behind.
Greater crested tern colony (Kitakojima Island)Photography: Yoshima Niiro
Greater crested tern eggs (Kitakojima Island)Photography: Yoshima Niiro
A small mole belonging to the talpidae family. One mole was collected on the grassland near the coast of Uotsuri Island in 1979. It is an academically invaluable species that was formerly classified as a monotypic genus.
Photography: Okinawa Development Agency
Photography: Okinawa Development Agency
Goats were first introduced on Uotsuri Island when a Japanese private political organization brought a pair (one male and one female) over from Yonaguni Island in 1978. In a field survey of the island conducted in 1979, the presence of four goats was confirmed, and it was found that 24 species of plants had been eaten by the goats. The number of goats on the island today has been estimated at 300 or 500, and the feeding damage is worsening, particularly along the coasts and the southern slopes. This feeding damage is a serious problem, with impact extending to the deterioration of invaluable flora and fauna, changes to ecosystems, and deterioration of topographical features.
An adult goat and kid walking over the rocky areas on the eastern side of the island.
Photography: Haruo Ogi
Photography: Yoshihiko Yamada
Changes around the inlet on the western side of the island. It is evident that the grasslands, which were visible over the top of the elevated coral reef in 1978, had completely disappeared by 2003.
Photography: Geospatial Information Authority of Japan
Photography: Geospatial Information Authority of Japan
Feeding damage to plants, observed during the survey conducted in 1979 Barren areas as indicated by an analysis of satellite images.
The surface area of the barren land has increased over the past 30 years and is reported to cover approximately 8% of the whole of Uotsuri Island.
Changes to vegetation from the coast to the ridge. Based on photographs from 2012, we can see that grassland and shrubs have disappeared from the coast, and only the fountain palm (livistona chinensis) forest has survived.
Photography: Yoshima Niiro
Photography: Yoshihiko Yamada
The aerial photographs show that the increasing denudation of the land is particularly prominent on the southern slopes.
Southern slopes of Uotsuri Island
Vegetation on the steep slopes has been fed on by the goats, resulting in increasingly exposed cliffs and serious landslides.
According to research conducted in 2012 by the Tokyo Metropolitan Government, it was confirmed that significant amounts of marine debris had washed ashore and become scattered across the beaches of Uotsuri Island, Kitakojima Island and Minamikojima Island. Sea birds and sea turtles often mistake marine debris for food and eat it. This is a serious nature conservation issue.
Like the Yaeyama Islands, The Senkaku Islands are located in the stream of the Kuroshio Current and serve as a conduit for marine litter generated by neighboring countries. Since marine litter is not only difficult to treat but it may wash ashore in unlimited amounts, remote islands all over Japan are afflicted by this same problem. International efforts are needed to solve this issue.
Countless numbers of fishing gear (Styrofoam or urethane buoys, fishing nets), driftwood, and other waste wash ashore.
Photography: Haruo Ogi
A former base of business activities (former Koga Village). Marine debris is scattered across most of such flat land areas.
Photography: Tokyo Metropolitan Government
Large amounts of household waste, including styrofoam and plastic containers, can be seen.
Photography: Yoshihiko Yamada
Much of the plastic waste cannot be broken down and can cause damage to beach ecosystems.
Photography: Yoshihiko Yamada
The wreckages of several ships, believed to be from small boats shipwrecked on Minamikojima and Kitakojima Islands, have been found.
Photography: Koichi Yamamoto
Various objects, exposed to strong winds and rough waves, are thrown onto the shore.
Photography: Yoshihiko Yamada
